Bowling Bash

The Great British Bake-Off

noreply@blogger.com (gentimouton) — Sun, 26 Mar 2017 06:57:00 +0000

The Great British Bake Off (GBBO) is a 10-episode show that started in the UK in 2010.

It is hugely popular. The finals of October 2016 were the most-watched show that year, with 14M viewers. For context, it's up there with the England vs Slovakia soccer game of June 2016 (14M viewers), the World Cup soccer finals of July 2014 (15.0M viewers), and the Queen's Diamond Jubilee of 2012 (14.7M viewers).

I think the show is so popular because of its format. It keeps some parts from MasterChef, introduced in the 1990s, but also adds its own twist. The MasterChef format is: cooking meets reality TV's cutthroat competition fueled by drama. It features professional chefs judging and eliminating contestants every episode. It's a recipe for great entertainment.

GBBO keeps the competitive structure from MasterChef, but makes it is much friendlier, and it tones down the ruthlessness and drama. The judges themselves admit that it appeals to children, grannies, workers, everybody, because it's gentle. For example, when a MasterChef contest starts, the contestants run throughout the kitchen to grab tools and ingredients right away. In contrast, the GBBO contestants are given their own appliances and ingredients, and choose their own recipes for their Signature and Technical Challenges. They are often caught on camera comforting each other and joking with the two comedians, who add comic relief to stressful situations (although some viewers could find their humor cringeworthy at times). In the finals, they keep 3 contestants as opposed to only 2, so that losers congratulate the winner right away instead of being disappointed.

GBBO has only two judges, not three. Other competition shows like Britain's Got Talent have three because they vote on accepting or rejecting a contestant. This vote is public and recorded on camera sometimes with much drama. The GBBO judges on the other hand are always deliberating privately, and nearly always reach a consensus on who they're kicking out.

Another appealing feature of GBBO is the setting of the competition. MasterChef takes place in a warehouse, with lots of steel accessories. It looks stressful. GBBO takes place in a luminous tent placed in a very green and bucolic countryside. The transitions between Challenges are shots of sheep and tree leaves. It's a much more pleasant viewing experience.

The protocol at the end of each GBBO episode also focuses on the positive parts. They first announce this week's Star Baker, which awards a silver Sheriff star to the week's best baker (Star Baker was added in Season 2). Star Bakers wear the star in the next episode, until the next Star Baker is announced. After the Star Baker is announced, they call the contestant who is eliminated. At that point the two comedians and a bunch of the other contestants hug them, sometimes in tears.

Another appealing feature (probably) introduced by MasterChef is that viewers can see multiple amateurs making the same dish in their own ways. Amateur contestants and professional judges offer practical advice, and show the recipe in action. GBBO's twist is the addition of nice illustrations of each contestant's Signature and Showstopper Challenges before they start making them. This gives the audience a visual expectation of each recipe. For the Technical Challenges, GBBO shows a standard professional version of the expected bake.

GBBO's Technical Challenges are also interesting because the two professional chefs judge blindly. This tells the audience that there are no favorites in the show.

Because GBBO focuses on the presentation and the contestants, they do not dig too deep in the details of the recipes. This has led critics of the first season observe that viewers learnt next to nothing about how they were actually making them. I think this is another reason for the show's success: the target audience is not bakers looking for new recipes, it's viewers looking for amazing-looking breads and pastries with a zest of drama.

Shop Heroes - Opaque UI

noreply@blogger.com (gentimouton) — Thu, 04 Feb 2016 02:57:00 +0000

Shop Heroes is an item-shop game released on mobile and Kongregate in mid 2014 by CloudCade. The gameplay consists of crafting equipment for heroes, who then go on quests to find materials, which are used to craft more equipment. Players can gather in Towns to share the costs incurred by leveling up buildings, which unlock more heroes and quests.

CloudCade advertise striving for useability and superior gameplay. I understand that when they launched Shop Heroes, they were still a small studio. But their UI needs more work: it has too many screens, too many taps to start an action, too much information, and fragmentation/duplicate information. Sometimes, information is not just missing or duplicated. It's purposefully hidden, misleading, or manipulative.

Manipulating emotions

An example of UI manipulating emotions is the Roulette, which gives players one random award among 12. The UI shows each award equally likely to happen - 1 in 12, or 8% each. Yet the actual chance of keys, gems, and blueprint fragments is less than 1%. Why raise players' hopes so high if it never delivers? So they get 10 seconds of fiero after 10 months of frustration? It's as if a slot machine displayed the jackpot symbol with the same chance as others, but was actually rigged to nearly never stop on it. The gambling industry actually forbids such machines. One could argue that the Roulette is a minor mechanic in Shop Heroes, and that players may understand that it's rigged. A sincere UI would make the area of a reward on the wheel proportional to its likelihood.

Hidding information

An example of UI purposefully hidding important information can be found in the screen where players build their quest teams. Players send heroes on quests dozens of times per day. When heroes are strong enough to tackle the quest, a green smiley is displayed above their head. When they are not strong enough, the smiley turns to yellow or red, showing that they are more likely to be injured. Injured heroes are unusable for several hours, so players strive for green smileys. But each of the 8 equipment slots of each hero has a 1-10% chance to break during a quest. Therefore players equip their heroes with just enough equipment to reach green smileys, so as to minimize the costs incurred by broken equipment.

Yet players noticed discrepancies in the odds of injury. They asked on the forum whether increasing power above green smiley reduces the chance of injury. The community manager did not answer clearly at first, saying it's fun for those playing to figure out, and that it's impossible to create a tutorial for every single detail in the game. Players replied that 1) they are not asking for a tutorial but for explicit numbers to be displayed, 2) core mechanics should not be hidden, and 3) discovering 1%-likelihood mechanics is annoying and time-consuming. The community manager eventually cleared the matter, but why was this important information not explicitly provided inside the game? The in-game UI should, and can, do a better job at displaying the chance of injury, however small it is. One way would be to display the green smiley only when the chance is exactly 0%. Another way would be to display the percentage number, rounded up (0.123% would be 1%). Providing feedback through numbers is the only way that hardcore players can theorycraft and reverse-engineer the most intricate mechanics.

Powerball lottery - Boosting jackpots to boost sales

noreply@blogger.com (gentimouton) — Thu, 28 Jan 2016 03:06:00 +0000

The January 2016 jackpot reached $1.5B because the carried-over jackpot increased faster than ever before in the streak of 19 drawings without winner. To show this, the table below compares the $1.5B jackpot to the $564M jackpot of February 2015, which concluded a streak of 20 drawings without winner.

Streak	Jackpot amount ($M)
Streak	Jan'16	Feb'15
15	255	208
16	300	230
17	334	261
18	529	289
19	948	317
20	1,500	395
21	-	564

Streak	Tickets sold (M)
Streak	Jan'16	Feb'15
15	26	24
16	41	28
17	54	29
18	176	37
19	440	48
20	635	73
21	-	190

The February 2015 jackpot reached half a billion dollars after 20 consecutive drawings without winner. The January 2016 jackpot reached three times that amount in one drawing less. In fact, it is surprising that the January 2016 jackpot could triple from $529M to $1.5B in two drawings. What happened?

Funding Powerball's jackpot

To understand how jackpots build up, we have to understand some of the inner workings of the Powerball lottery. The 2015 Powerball group rules published by the Multi-State Lottery Association (MUSL) managing Powerball are sometimes ambiguous, so this section may not be perfectly accurate. To keep it simple, the Power Play option is ignored.

Although MUSL runs Powerball, each state lottery is in charge of advertising, selling tickets, and giving non-jackpot prizes to their respective winners. Each state lottery keeps half of ticket sales, which probably directly goes into the state's budget. The other half funds MUSL's four accounts: the prize pool, jackpot pool, bootstrap pool, and reserve.

The prize pool (aka Powerball Set Prize Pool) is filled weekly by each state lottery to pay the small prizes. Ignoring Power Play, it should receive at least $4 / 38.32 + ... + $1M / 11.7M = 32 cents per ticket to be able to pay out the prizes. In-between two drawings, its balance is close to zero.

The jackpot pool (aka Grand Prize Pool) holds the jackpot money. When the other pools (usually the bootstrap pool) need to be topped-up, up to 5% of sales is transferred from it to them. By the time the jackpot reaches $110M annuity/$70M cash, ticket sales have filled all other pools, and the jackpot pool receives the full 68 cents per ticket.

The bootstrap pool (aka Set-Aside Account) backs up the jackpot pool when the jackpot is won at the beginning of a streak. For example, every streak starts with a jackpot of $40M annuity/$25M cash. These drawings usually sell 10 million tickets, ie $20M in sales. The state takes $10M, small prize winners $3.2M (32 cents per ticket), and so there is only $6.8M left to pay the $25M jackpot. The extra $18.2M comes from this pool. Fortunately, 10M tickets have only 4% chance to win the jackpot, so the bootstrap pool is rarely emptied. It is filled by "taxing" the jackpot pool 5% of sales, ie 10 cents per ticket, until it has reached its $20M cap.

The reserve (aka PRA and SPRA) exists so that MUSL does not get bad press for not paying winners their full prize. This could happen because of a system error, miscalculation, or because all other pools are depleted. When the reserve itself is depleted, prizes stop being fixed (eg $1M or $7) and become parimutuel to prevent breaking the bank. Until the reserve reaches its $40M cap, filling it takes precedence over the other pools.

January 2016 vs February 2015

To illustrate how these pools work, we can use the streak of 20 drawings leading to the jackpot of $1.5B annuity / $930M cash as an example. The streak starts on November 7, when 374k 2-dollar tickets and 101k 3-dollar tickets won small prizes. Ticket sales (estimated) are 24.87 * (374k * $2 + 101k * $3) = $26M. The state takes $13M, and small-prize winners $4M. Let's imagine that the reserve is full. The jackpot had reached $90M cash on November 4, so the bootstrap pool should be full, but to illustrate its workings, let's assume it is empty. Since the jackpot is not won, the bootstrap pool receives 5% of sales = $1.3M. The jackpot pool receives the remaining $7.7M. This process goes on until December 19, when the bootstrap pool reaches its $20M cap. All these numbers are listed in the first table below.

On closure day, January 13, when the $930M cash jackpot is won, the ten-week streak has raised a total of $3.4B. Around $623M has been paid to small-prize winners, $930M shared between the jackpot's three winners, and $1.7B kept by the states. As for the February 2015 jackpot, the states only received $679M in roughly the same amount of time (ten weeks and a half). Judging from these two jackpots only, the 2015 tweaks seem to have tripled Powerball's profits.

Pool amounts (in $M) leading to the $1.5B annuity jackpot
date	jackpot (cash)	ticket sales	prize pool	jackpot pool	bootstrap "tax"	bootstrap pool
11/7	25	26	4.2	7.6	1.3	1.3
11/11	32	22	3.0	15	1.1	2.4
11/14	38	28	4.1	23	1.4	3.8
11/18	44	24	7.7	26	1.2	5.0
11/21	50	27	6.4	32	1.3	6.3
11/25	57	28	3.1	41	1.4	7.7
11/28	63	28	4.8	49	1.4	9.1
12/2	69	32	3.7	59	1.6	10.7
12/5	80	38	8.2	68	1.9	12.6
12/9	91	33	5.5	78	1.7	14.3
12/12	103	38	7.4	88	1.9	16.2
12/16	113	39	6.2	99	2.0	18.2
12/19	127	51	9.6	113	1.8	20
12/23	143	58	9.9	132	full	20
12/26	161	54	6.3	153	full	20
12/30	189	84	14	181	full	20
1/2	210	118	21	219	full	20
1/6	333	375	66	341	full	20
1/9	597	963	159	663	full	20
1/13	930	1,374	274	1,077	full	20
closure	930	3,440	623	0	NA	20

Pool amounts (in $M) leading to the $564M annuity jackpot
date	jackpot (cash)	ticket sales	prize pool	jackpot pool	bootstrap "tax"	bootstrap pool
12/3	26	22	2.2	7.7	1.1	1.1
12/6	33	26	4.4	15	1.3	2.4
12/10	39	25	4.1	22	1.2	3.6
12/13	46	27	4.8	29	1.3	5.0
12/17	52	25	4.4	36	1.2	6.2
12/20	59	32	10.2	40	1.6	7.8
12/24	65	35	9.2	47	1.8	9.6
12/27	72	32	10.3	51	1.6	11.1
12/31	78	38	8.4	59	1.9	13.1
1/3	85	35	4.6	70	1.7	14.8
1/7	95	35	5.0	81	1.8	16.6
1/10	105	41	10.2	90	2.1	18.6
1/14	114	38	7.0	100	1.4	20
1/17	126	48	16	108	full	20
1/21	135	52	12	122	full	20
1/24	150	62	18	135	full	20
1/28	170	60	11	154	full	20
1/31	188	74	15	176	full	20
2/4	206	100	18	209	full	20
2/7	257	151	30	255	full	20
2/11	381	401	74	381	full	20
closure	381	1,358	278	0	NA	20

The Powerball tweaks have only been implemented for three months now. With little data to rely on, it is not guaranteed that profits will stay triple what they were before. Profits may have soared this time because of the buzz surrounding the record-breaking jackpot. The next billion-dollar jackpot may see mediocre sales because people got tired of Powerball or found other games to play. Will the next billion-dollar jackpot generate a billion dollars in profits? Will players adapt to the new odds? We will probably find out within a year.

Powerball lottery - Tweaks

noreply@blogger.com (gentimouton) — Wed, 27 Jan 2016 03:00:00 +0000

The jackpot fatigue theory

The Powerball mechanics have been tweaked several times since it started in 1992. Starting in January 2012, the game had 59 white balls and 35 red balls so that a billion-dollar jackpot would happen every 10 years. No such jackpot happened until the rules changed again in 2015, but as the table below shows, the jackpot reached half a billion several times.

Jackpots above $300M, 2012-2015
Date	Jackpot ($M)	Tickets (M)
2/11/2012	336	89
8/15/2012	337	86
11/28/2012	588	286
3/23/2013	338	80
5/18/2013	591	243
9/18/2013	399	93
2/19/2014	425	86
2/11/2015	564	191
9/30/2015	310	51

Powerball sales dropped 19% nationally in 2014. Lottery officials suggested two explanations: the lack of a huge jackpot in 2014, and jackpot fatigue: lotteries need increasingly bigger jackpots to attract the casual players who only buy tickets when the jackpot is huge.

The table above confirms that there was only one jackpot above $300M in 2014, but it rejects the fatigue theory. For jackpots between $300M and $350M, the number of tickets sold decreased from 89M in 2012 to 51M in 2015. And for the three jackpots between $550M and $600M, the number of tickets sold went from 286M in 2012 to 191M in 2015. Sales from the biggest jackpots lost 35% in three years.

Yet, the fatigue theory made New York state lottery officials shift their focus from jackpot-driven games, where jackpots get very big too rarely, to instant scratch-off games with more frequent prizes. New York state is a major actor in the Powerball lottery: it ranks third in ticket sales, after California and Florida. So it's likely that the tweaks of October 2015 were an attempt to address jackpot fatigue.

October 2015 tweaks

In October 2015, white balls increased from 59 to 69, and red balls decreased from 35 to 26. Thus the odds of winning a prize increased from 1:32 to 1:25, but the odds of winning the jackpot decreased from 1:175M to 1:292M. Lower jackpot odds means longer streaks until the jackpot is won, ie bigger jackpots. Projections made in 2012 suggested that a billion-dollar jackpot would happen every 10 years. Data from November 2015 to January 2016 suggests that billion-dollar jackpots should now happen every year or so, and there is a 63% chance for one to show up within 5 years. This tweak is similar to the British National Lottery tweak of June 2015: 5 balls used to be picked among 49, which was raised to 59, resulting in the £58M jackpot of January 2016, the largest in the National Lottery's history.

Decreasing the odds of winning the jackpot decreases the expected value of a ticket. This expected value is plotted in the graph below, against the jackpot value. Before the rule change, the jackpot had to reach $200M for a ticket to be worth $1. Based on drawings data from 2015, $200M jackpots were expected to occur every 24 weeks. Now, after the rule change, a ticket is worth $1 when the jackpot reaches $450M, which is expected to happen every 34 weeks.

Long story short, the October 2015 tweaks increased the chance of winning a consolation prize, but decreased the chance of winning the jackpot and the expected value of a ticket. Since the expected value of a ticket estimates how much each lottery ticket costs to the organizers, their profits must have increased!

Powerball lottery - Odds, expected value, and billion dollar jackpots

noreply@blogger.com (gentimouton) — Tue, 26 Jan 2016 02:58:00 +0000

Basic odds and expected values

Wikipedia has a good introductory page about lottery mathematics. In short, the number of possibilities for drawing 5 white balls among 69 and one red ball among 26 is C(69,5) * C(26,1) = 292M. Despite these very low odds, 14 people won the jackpot in 2015, and 72 from 2011 to 2015. The chances of winning prizes are listed in the table below. The expected value column is the product of a prize by its odds.

Match	Prize	Value	Odds	Expected value
5 whites + red	Jackpot	$40M to $1.5B	1 in 292M = .00000034%	$0.14 to $5.14
5 whites	Match-5	$1M	1 in 11.7M = .0000085%	$0.09
1-4 whites + red or 3-4 whites	Consolation	$4 to $50k	1 in 24.7 = 4.04%	$0.24

The Powerplay mutliplier applies only to consolation prizes. Taking into account the probability of each multiplier, their expected value becomes $0.65. Power Play also doubles the Match-5 prize by 2, so the Match-5 expected value becomes $0.17. While Power Play does increase values, it does not increase them by enough to cover the $1 cost of the Power Play option. Power Play is not worth it.

Huge jackpots do not justify buying a ticket

Intuitively, the January 16 2015 jackpot of $1.5B is so huge that it may seem statistically worth it to buy a ticket: you spend $2 to receive $1.5B / 292M = $5.14. Each ticket would net $3.14. Put another way, one could earn $1.5B after investing 292M * $2 = $584M. The theory is promising, but it has flaws.

First, 635M tickets were sold. An alternative way to find this number is to mutliply the number of winners by the odds of winning: 26.11M * 24.87 = 650M tickets. Based on the method described here, there is an 89% chance that there is another winning ticket. More specifically, the chances of having exactly 0, 1, 2, 3, 4, and 5 winners among the 650M tickets already sold are 11, 25, 27, 19, 11, and 5%. Taking these probabilities into account, $5.14 becomes $5.14 * (11% / 1 + 25% / 2 + 27% / 3 + ... ) = $2.09. So, buying a Powerball ticket is still (barely) worth it. Second, there is a 40% federal income tax on lottery winnings. That brings it down to $1.26 per $2 ticket. Buying a ticket for the $1.5B jackpot is not statistically worth it anymore.

Last, all tickets have to be bought in person. Since Powerball drawings happen twice a week, one would have to buy 70M tickets per day, or 845 per second. CNN reports that in February 1992, an Australian consortium tried to corner a $24 million Virginia Lotto jackpot. But the group was only able to purchase 2.4 million of the 7 million combinations before time ran out.

Billion-dollar jackpots every year

Could the jackpot get big enough that buying a ticket will be statistically worth it? There is no data point after $1.5B, so we can't say. But we can compute the expected time until such a jackpot appears again.

First, For the jackpot to reach $1.5B after 20 drawings, all 957 million tickets from the previous 19 drawings had to be losers. That is a 4% chance. Then, we can adapt the coin-toss method, using ticket sales and jackpot values for the 20 drawings leading to the $1.5B jackpot, to compute the expected time until the jackpot reaches $1.5B. Unless my math is wrong, I found that the expected number of drawings to reach 19 consecutive drawings without winner is 421. With two drawings a week, that means a $1.5B jackpot should appear every 4 years. A billion-dollar jackpot requires 18 consecutive drawings without winner, which can be expected every year.

Powerball lottery - Rules and patterns of play

noreply@blogger.com (gentimouton) — Mon, 25 Jan 2016 02:57:00 +0000

On January 13 2016, the Powerball lottery made the news by reaching a jackpot of $1.5B, the largest in US history. Lotteries are interesting because they are a gambling game used by governments to raise funds without raising taxes. Let's have a closer look at the rules, odds, and profits made by lotteries, using Powerball as an example since it's one of the lotteries with highest sales.

Basics

The official simplified rules stipulate that five white balls are drawn among 69, and one red ball among 26. The jackpot is won by matching all five white balls in any order and the red Powerball. The jackpot starts at $40M, and increases every drawing by at least $10M until won. Combined with the minuscule odds of being won, this mechanic makes it possible for the jackpot to become huge. The match-5 prize, worth $1 million, is won by matching five white balls in any order. Consolation prizes, worth $4 to $50k, are won by matching at least three white balls or at least the red Powerball. Tickets cost $2. Players can buy as many tickets as they want.

Drawings happen twice a week, on Wednesdays and Saturdays. The boxplot below plots the median number of tickets sold per drawing. Data consists of drawings with jackpots below $200M, from April 13 2013 (right after California joined the Powerball group) to January 20 2016. Drawings sell an average of 14.0 million tickets on Wednesdays, versus 15.4 millions on Saturdays (p=.0001).

Jackpots predict sales

Ticket sales are very predictable from the jackpot amount. This is shown in the graph below. For jackpots under $300M, the number of tickets sold increases quadratically with the jackpot. Above $300M, we do not have enough data to build a model, but the trend seems logarithmic, probably because ticket sales grow much faster than the jackpot.

Optional features

Power Play is an optional feature that launched in 2001. As of 2015, it multiplies the value of non-jackpot winnings by 2 to 10 by paying an extra $1 per ticket. A wheel determines the multiplier for each drawing (24/43 chance for 2x down to 1/43 for 10x). Interestingly, Power Play used to have a 1x multiplier, but it was removed within a year. Why have a bonus that is sometimes not a bonus?

Random picks: Players can choose their 6 numbers themselves, or have the computer pick them randomly. About 70% to 80% of purchases are computer picks.

Annuity vs cash

Jackpot winners can choose to receive their share of the jackpot immediately through a 30-year annuity, or immediately in cash. When winners choose the cash, they immediately receive the advertised cash amount, which is usually 60-70% the annuity amount. That is why the lottery organizers advertise the jackpot's annuity, and not its cash.

When winners choose the annuity, they immediately receive 1/30th of the cash amount. The organizers invest the rest into government bonds or securities. Every year for 29 years, they sell 1/29th of the bonds and give the proceeds to the winner, with a 5%-interest per year. Choosing the annuity prevents people from blowing through all their money quickly. Yet only one jackpot winner out of 72 chose the 30-year annuity from 2011 to 2015.

Hearthstone - match-making and bottom-feeding

noreply@blogger.com (gentimouton) — Fri, 20 Nov 2015 04:10:00 +0000

Most players play every day to win their daily quest. Most daily quests involve winning in PvP matches. Thus, many players end up bottom-feeding: they keep their PvP ranking low so as to win more easily and complete their daily quest faster. That's why 90% of Hearthstone players are below rank 10 in ranked mode.

To reach the number of wins for their daily quest faster, players may want to concede and start another game when they see they have no chance in the current one. There are several techniques to gauge an opponent and the likelihood to lose:

A golden hero protrait indicates the player has won 500 games with that hero. It is a veteran player, most likely with lots of good cards.
Decks composed of 4+ legendary cards, especially Sylvanas, Dr. Boom, or Alexstrasza, are from players who spent a lot of money.
Purchased heroes means the player has certainly spent a lot of money on card packs as well.
A legendary card back indicates the player was dedicated enough to reach the top .25% of the player base.
Old card backs indicate the player is a veteran, and must have good cards.
Heroic dungeon card backs are awarded for clearing a dungeon in heroic mode, which requires many good cards.

Having players with different skill levels playing together is problematic. Veteran players tend to have better cards and more skill than beginners. As a result, beginners may frequently go on long loss streaks. Loss streaks are very unpleasant, and come to mind faster than win streaks. So when players talk to their friends about Hearthstone, they are more likely to complain than to brag. That won't encourage their friends to start playing.

There are solutions to bottom-feeding. One solution is to pool beginners together so they don't get beaten up too quickly. Another solution currently in place in Casual Play, Tavern Brawl, and legendary-rank games, is using a ranking hidden from players such as MMR. Hiding player's rank from them prevents them from knowing where they stand, and the average skill and cards to be expected from their opponents. But players can easily cheat the system and drop their MMR by conceding games before they even started.

A great solution would be to consider both the player's ranking (as is currently the case) and the rarity of the cards in their deck. In fact, websites listing Hearthstone decks already take into account the rarity of the cards in a deck by providing a dust cost. Epic and legendary cards cost a lot of dust, and are either useless (and therefore unused), overpowered (and therefore always used), or the keys to unlocking synergies in a deck (which is where the game is interesting). I think it would make sense to at least take them into account when matching players together.

Hearthstone - grinding for cards

noreply@blogger.com (gentimouton) — Thu, 19 Nov 2015 04:08:00 +0000

Players who spend $0 in Hearthstone (whom I call free players) can only obtain new cards from coins. Coins come from daily quests. Most daily quests involve winning 3-5 games against other players. Because PvP involves so much luck, winning games is about trying long enough. Thus the only way for free players to obtain new cards is to grind. How long is the grind for new cards?

The first step in obtaining new cards is unlocking the Naxxramas and Blackrock dungeons. How much time does that take a free player? Each dungeon costs 3500 coins. Daily quests give 50 coins per day, so unlocking them both takes 5 months. And that is assuming that during these five months, the free (yet dedicated) player is not buying any card packs with coins. I could understand that the less committed free players would quit out of desperation. Blizzard may have realized that too, so they introduced two new ways to obtain card packs: Tavern Brawl, awarding one pack per week, and Watch and Learn, a daily quest awarding a card pack for spectating a battle.net friend winning a game. Watch and Learn actually killed two birds with one stone, since it also was the first (and still is the only) incentive to socialize.

Once the dungeons are out of the way, free players receive a card pack every other day. After 3-4 months, nearly all commons and half of all rares have been acquired. But players eventually need specific legendary cards to increase their win ratio. How much time does it take a free player to get a specific legendary card? Since a legendary card costs 1600 dust, and a card pack awards 90 dust on average, it takes a free player 5 weeks to gather enough dust to buy one specific legendary card. And that is assuming that the player trashes all cards found in packs, including those of rare, epic, and legendary rarities. If they keep the epic and legendary cards, a card pack only awards 39 dust on average, and obtaining a specific legendary card takes 6 weeks.

Not all legendary cards are worth keeping. Competitive decks require 2 to 4 legendary cards, ie 5 months of grinding. Moreover, there are 9 classes in Hearthstone, each with different legendary card requirements. Since Blizzard releases new cards every 6 months, no free player can seriously think of collecting all the cards in Hearthstone.

Hearthstone - crafting

noreply@blogger.com (gentimouton) — Wed, 18 Nov 2015 04:07:00 +0000

Hearthstone has a soft currency called dust. Dust is used to purchase a desired card from Blizzard. Common cards cost 40 dust, legendary 1600. Dust is obtained from trashing cards: 5 for common cards, 400 for legendary. Players who want a specific legendary card are very unlikely to find it in a card pack. But they can trash the cards in the card pack for dust, and use that dust to buy it.

Blizzard gave a special name to purchasing with dust and trashing cards for dust: crafting and disenchanting. Yet this mechanic is far from the crafting we are used to in RPGs: no additional material is required beside dust, and all cards follow the same recipe. Rarity only increases cost. So why calling it crafting/disenchanting, and not buying/trashing? Why make a fancy UI, pretending that players are actually creating a card themselves, and not buying it from the store? I think it was so that players perceive dust as a regular game element, and not a currency. That way, players don't feel like they are purchasing dust (through card packs) with real money at all.

Blizzard actually introduced direct-purchasing (aka crafting) as a solution to what they say is a common trading-card game issue: when players obtain a rare card, they want to keep it, and they'll never trade it with other players. But that rationale is flawed. People who buy card packs will sell their duplicates if the game provides them an auction house. Blizzard probbaly did not want to go that route after their Diablo 3 auction house was overrun by gold farmers.

Hearthstone - luck-based mechanics

noreply@blogger.com (gentimouton) — Tue, 17 Nov 2015 04:06:00 +0000

I covered Hearthstone in a previous post, but there is more to say. Hearthstone is a collectible card game (CCG) for Windows, iOS, and Android, by Blizzard. Its gameplay is very similar to Magic: The Gathering, and its theme is World of Warcraft. It is free to play, but players can purchase coins, which are spent to acquire card packs or unlock certain cards. Hearthstone launched in March 2014.

Influx of new players

Hearthstone has seen 30M players and generated $250M as of May 2015. Hearthstone had 25M registered players in January 2015. That means 15% of the player base (5M players) have been playing for less than 6 months. This is very good: a constant influx of new players keeps a game alive.

Luck-based mechanics

Many mechanics in Hearthstone are based on luck. Very few mechanics help manage that luck.

Mechanics involving luck in Hearthstone
Mechanic	Description	Solution
Topdeck	Drawing by luck the right card at the right time	Filtering cards like Tracking
Starting hand	3-4 cards out of a deck of 30	One Mulligan (redrawing unwanted cards)
Card effects	E.g. deal 2 damage to a random enemy, or get a random beast.	Anticipating all possible outcomes
Card packs	After 2 months, most cards from packs are already owned and redundant.	One card per pack is guaranteed to be rare or above. Convert redundant cards into crafting dust. Collect golden cards.
Match-making	Random opponent decks that may be very (in)effective against yours	Tavern Brawls with pre-made decks. Best-of-3 in championships.
Match-making	At rank 15-20, opponent skill varies greatly.	Provide incentives against bottom-feeding.

When playing for skill, all luck aspects can be annoying. In my experience, topdecking and random card effects have been the most frustrating: a strategy works, it's about to win against an opponent, but the opponent draws the right card, or receives by chance the one perfect card to counter the strategy. Some decks such as Oil Rogue even rely on making a combo of 4 particular cards in the same turn. If these cards are in the starting hand, these combos fire after a couple turns, and the loser feels like the game was over before it even started. Unlike in Dominion, strategy in Hearthstone is too heavily mitigated by chance.

Gravity EU changes XP rates to prevent botting

noreply@blogger.com (gentimouton) — Fri, 30 Oct 2015 01:49:00 +0000

Gravity Europe is the company running the European Ragnarok Online (euRO) server. Players can play on euRO for Free or by subscribing to a Premium account for 5 euros per month. Premium accounts also provide perks such as more character slots, more space to store items in the game, and a lower XP penalty on character death.

Gravity EU sent an email on October 22, 2015 to notify their players of a change in XP and drop rates:

Dear Adventurer,
As we have been aware that bots are polluting our server more and more every day, we've decided to act and make botting less attractive than it has been so far. From now on, the XP and Drop rates will change for both our Free and Premium users. Indeed, below you will find the comparison between previous and new rates:
Previous rates: Free Players: 100% XP and 100% drop. Premium Players: 150% XP and 100% drop.
New rates: Free Players: 75% XP and 75% drop. Premium Players: 175% XP and 150% drop.
As you can see, we also increased the Premium rates as a thank you to our loyal players and we hope that these changes will make our server a better place to live and play on, for everyone.
Enjoy your time on Ragnarök Online!
Gravity Europe Team

This decision is wrong for several reasons:

Reducing the drop and XP rates for bots from 100% to 75% does not solve the botting problem. Bots on Free accounts are now simply 33% less productive, while bots on Premium accounts 50% more so. Bots are still here.
The gap between the Premium and Free rates was moderate. Now it is more than 2x. Why would anyone play for free now?
Using botting as an excuse to change the rates is a marketing ploy. If Gravity EU had increased the rates without mentioning botting, and only as a thank you to our loyal players, it would have felt like they were forcing players to go Premium. In contrast, by justifying their change with botting, Gravity EU is telling their players: go Premium to fight the bots!
RO came out in 2002, so its graphics and game mechanics are a bit outdated. Yet, like any MMO, RO must attract new players for its community to survive. Having made the game free was a good first step, but Gravity EU also has to work on players acquisition. Most new players start playing the game for free, to try it out. Reducing the drop rates for the free players certainly hurts day-1 retention.
The decision to change the rates is framed as a loss for Free accounts and a small gain for Premium accounts (and not as a solution against bots). The decision could have been framed as a large gain for Premium players and no change for Free players. Make it a reward! In fact, the Premium Service page frames it as a 100% vs 230%, not a 75% vs 175%. Why was it not framed that way in the email?

Finding a solution to botting is actually easy. Some private RO servers implemented periodic captcha popups: every 30 minutes, the game kicks out the players who fail to answer a random but easy test (such as 1+2=?). A bit inelegant, but very effective.

Habits

noreply@blogger.com (gentimouton) — Sun, 13 Sep 2015 21:55:00 +0000

Notes from a French magazine called Ca m'interesse from January 2014. One article talked about choices, habits, and routines. Some findings are applicable to game design.

Richard Weiseman, a psychologist, followed 3000 people taking New Year resolutions. Half say they will hold their resolution on day 1. 12% manage it after one year. Weiseman gives tips on how to keep your resolutions, such as telling others about your resolution (to put peer pressure on yourself), avoiding previous (failed) resolutions (to prevent frustration), breaking it in smaller achievable steps (to prevent hopelessness), and giving yourself rewards for achieving these steps (positive reinforcement). It's been covered elsewhere too.

Based on previous research, Philippa Lally, another psychologist, suggests that it takes around two months working effortfully on new behavior to turn it into a habit.

Future hypothetical rewards (e.g. slim body in a month) are higher to accept than instant gratification (e.g. eat tasty food right now) because they require an effort of imagination. Solution: make future rewards more visible.

Baba Shiv, professor of marketing, asked 165 undergrads to pick either a chocolate cake or a fruit salad. The chocolate cake has a positive affect and negative cognition, ie it's emotionally appealing but you know you should not take it. The fruit salad is the opposite: negative affect and positive cognition, ie it's the rational healthy choice. In both groups, participants were asked to remember a number throughout the experiment. One group was given a 2-digit number (low cognitive load, ie high processing resources) and the other a 7-digit number (high cognitive load, ie low processing resources). 41% of the 2-digit group picked the tasty cake vs 63% in the 7-digit group. Under heavy cognitive load, people are more likely to choose options that are immediately pleasing. As a side note, when the presentation of the choice was through photos rather than the actual items, the difference between the two groups disappeared.

If I perceive a task as more difficult, I will expect a higher reward. It is not just about being strong-minded, but also about my perception of the task's difficulty.

Game of War

noreply@blogger.com (gentimouton) — Fri, 07 Aug 2015 00:24:00 +0000

Game of War is a mobile game currently making $1.2M/day and having 2.2M daily active users. Its developer, Machine Zone, is valued at $3 billion (while Zynga is valued at $2.7 billion and Supercell at $5.5 billion.).

The game is quite high up the charts of the App Store, only surpassed by Clash of Clans' $1.7M/day and 4M daily active users and probably Candy Crush as well. CoC and GoW are similar in that they are both free-to-play empire-builder war games for mobile. Whereas I find CoC to be a polished game with elegant mechanics, Game of War is said to be everything wrong with mobile monetization. Let's have a look!

Copycats

In an interview in 2012, Gabriel Leydon, Machine Zone's CEO, said they are making games that are very, very special and unique in the market. But in the same interview, he also said If you want to scale fast and you have the ability to do it cheaply, you just clone. With GoW, they did not go the special/unique route: they cloned 99.9% of their gameplay and UI from Kabam's The Hobbit (which launched for mobile in October 2012). Shameless cloning is a common practice among mobile games, and The Hobbit itself had cloned a lot of its gameplay and UI from Evony (a Flash game from 2009), which itself had cloned most of its gameplay from Civilization.

Going back to GoW, the trailer features a battle in real time scene that actually never happens in the game. In the game, the player can see their armies move in real time, but when battles happen, the player only sees a report of the troops expended and resources gained. No visual battling actually happens. So the game launched with a lot of hype and exaggeration. Since it's a clone of The Hobbit, the marketing team had to exaggerate to compete.

Translation vs innovation

When GoW launched in July 2013, Venturebeat wrote they were using advanced technology, including a real-time translation engine, a sophisticated communications platform where players can send threaded emails, text chat, make comments, and share their feats on social forums. There really is nothing new or sophisticated with in-game emails. The translator, however, is GoW's unique attribute, what the game is known for. How good and useful is that famous translator?

When typing on the miniature keyboard of their iPhone, people use slang and make spelling mistakes. So the translator has to crowd-source a lot of sentences to players. For example, let's say a French player says "lu, a va bi1?". To translate this for American players, I think the sentence is first automatically-translated into English, leaving non-translatable words untouched: "read, have go bi1?". This gibberish is then given without context to 4 players who are told they'll receive in-game currency if they can fix the sentence. The first player fixes the sentence into "I read you, I have to go", the second suggests "Read (what I wrote above), I have to go and buy one", and so on. A fifth player receives the four tweaked sentences and is awarded some in-game currency for picking the sentence he thinks makes most sense. The player who wrote the chosen sentence receives coins, whereas the other three receive a thank you message with no reward.

This sounds like a good idea, but there's a reason why after all these years Google Translate still sucks, and why translator is still a job. "lu, a va bi1?" in proper French is "Salut, ça va bien?", which Google can translate easily to "Hi, how are you doing?". But most French players can write "hello" by themselves. In Kings of the Realm, a game very similar to GoW, I've seen many American players write to Russian players in Russian. In Hearthstone, the game has 6 emotes (for "hello", "well played", and so on), and needs no translation system whatsoever. Did GoW focus on and boast its (mediocre) chat translator at launch because it was the only thing that differentiated it from The Hobbit?

Cash grab

MachineZone was actually called Addmired when it started. They were developing dating apps. Maybe the name made sense at the time, but even for a dating app, it's a terrible name: are users going to get mired in ads? That no founder flagged the name as inappropriate tells a lot about the company's business model.

GoW reminds players that they can spend money every time they login. The first screen showed when logging in is the one below. The font is inelegant, reminiscent of Asian mobile games like Puzzle and Dragons. The fireworks at the bottom obstruct one of the products offered in the bundle. The bundle name is "Summer MEGA GOLD Sale!!!". And a timer of 30 minutes pretends that the sale will end within 30 minutes. In fact, the player only needs to log back in to get spammed by the sale again...

In Clash of Clans, no upgrade takes longer than 14 days. The game provides 5 builders, so the most intense players have something to upgrade roughly twice a week. In GoW, the longest upgrade times is 23 years. Nobody would wait 23 years for an upgrade to finish! The designers do not expect players to wait 23 years. Everybody understands that year-long waiting times are here only to make players skip them with money. No surprise that some players report having spent $9,000 in the game. A kid in Belgium even spent $46,000.

Sexy advertising

GoW spent $40M to run an ad where model Kate Upton shows her cleavage during the Superbowl. Some people were outraged, but this advertising strategy was already used heavily in 2009 by Evony. Using sex in ads is not new, but that does not excuse it. It's interesting that a company valued at $3 billion has only one product, and the content of and advertising for that product were both 99.9%-copied from another company's product. In contrast, Clash of Clans' core gameplay may not be original but the ad they ran during the Superbowl was funny, silly, and just more elegant.

In fact, GoW's ads could be worse. For example, Evony's advertising strategy was much more questionable than GoW's. Through iEvony, they rewarded players with game coins when they referred a friend or when a friend they referred purchased game coins with real money. In order to bootstrap the pyramid scheme, iEvony was invite-only. Evony also used any search-engine optimization trick they could, stole ad photos and game art, and showed soft-porn images that have nothing to do with the game. So GoW still has some way to go!

Why do GoW (and CoC) use ads? After all, they have so many players already that word-of-mouth should bring them more. In practice, only a small percentage of new players will keep playing the game past the one-week mark. An even smaller number will spend money. Thus these games aim at attracting as many players as possible, so as to increase the number of spenders. But there will come a time when there will be no more new players to draw to the game. But since 2013, the cost for attracting new players outweighs the average amount spent by players ($2.73 vs $1.96). Since players get tired of games eventually, these greedy business models are unsustainable.

Conclusion

GoW is an over-the-top cash grab using sex [ads] to fuel a game where sex really isn’t a factor. The game has a terrible UI plagiarized from another game, and a horrible gameplay also plagiarized from others. This is the kind of game that gives a bad name to free-to-play mobile gaming. I'm disappointed that millions of players follow the ads and don't see that it is so crappy.

Samurai Jack stories

noreply@blogger.com (gentimouton) — Sat, 14 Mar 2015 07:06:00 +0000

1: Haku was sealed by Jack's father, but returns when Jack is a kid. Jack's father is taken by Haku, but his mother and himself escape with the only sword harmful to Haku. Jack's mother sends Jack to hone his combat skills with tribes all around the world. She keeps the sword until Jack returns as a man.

2: Haku sends Jack to the future to avoid losing the fight. Jack lands in an ultra modern city. He enters a bar full of thugs, and meets archeologist talking dogs who explain that Haku has enslaved many worlds. Jack accepts to free their people from Haku.

3: Haku sends a thousand robot beetles against the dogs. Jack organizes their defense (traps, tools), and defeats all the robots by himself while the dogs are watching.

4: In the jungle, small blue guys tell Jack that the big elephant-like creatures they are using are dangerous, and should be punished. A priest of the elephants explains to Jack that the elephants have actually been enslaved by the small blue guys. Jack breaks the orb used to enslave the elephants.

5: In a pine forest, Jack meets the human scientists who designed Haku's beetle robots. They are good guys, and want to escape to the past in a spaceship. They build a jet-pack and cosmonaut suit for Jack. In space, Jack protects them from Haku's wasp-like robots, but realizes that by doing so, he will miss the time travel.

6. Mysterious female warrior comes to help Jack. She needs a jewel to free her Dad, captured by Haku. Jack could use the jewel to go back in time. They collaborate, save each other, flirt. When they find the jewel, she breaks it and Jack realizes she was Haku.

7. Magic well giving one wish is protected by 3 archers. Jack realizes they are blind but perfectly accurate because they use the noise made by people when they walk in the snow. Jack wears a blindfold and sees the world like them, through noises. He beats them, but the well is cursed, so Jack destroys it.

8. Jack is mad because bounty hunters keep harassing him. Haku uses Jack's anger to create an evil clone of him. Jack beats the evil clone by doing yoga to calm himself down, thereby absorbing him.

9. Submarine city said to have a time machine. Inhabitants are slave of Haku, want to give Jack to Haku to gain freedom. Haku breaks his promise, so they regret giving Jack, and help him fight Haku. After Jack frees them, they explain the machine rumor was a lure.

10. Jack called by a voice to a mountain core. At the core, lava golem = warrior trapped in stone by Haku. Only way to free him: Jack kills him after a fair fight so he joins Valhalla.

11. Shaky, ridiculously long bridge. Jack meets with Scotsman in the middle after 2 days walking on it. Arrogant Scotsman demands that Jack backs up, because he has bounty on his head. Jack refuses, Scotsman trolls with bagpipe, they fight for 2 days. Bounty hunters show up for them both, so they fight together and become friends.

12. Capone-like gangsters from the 20s want to steal magic Water Jewel and gift it to Haku. Jack seizes the opportunity to meet with Haku and teams up with gangsters. Jewel protected by fire, wind, and earth guardians. Jack beats them by making them mix. When Jack meets Haku, gangsters knock him on the head before he can attack Haku.

13. Haku wants to improve his propaganda. Goes to school, tells kids classic tales like Red Riding Hood or 3 pigs, in which Jack is the bad guy. Kids deny them.

14. Jack teaches a jungle tribe to defend itself against evil gorillas. They teach him to "jump good" by attaching weights to him. When they remove the weights, he jumps above trees.

15. 3 tales. 1) Jack is lost. Giant double-headed magic worm says: "One of my head always says the truth, the other always lies. Solve enigma and we show you the path". Jack solves, but the worm eats him anyway. 2) Robot family, want to eat everything, but prefer metal (Jack's sword). When Jack rips one apart, they realize they are made of metal, and eat each other up. 3) Wish fairy protected by gargoyle. Jack frees her but his hand gets locked with hers. Gargoyle wakes up, Jack kills it, gargoyle laughs because only he knew the magic word to remove the manacles. Jack has no other choice but to say "I wish we were free".

16. Jack captured, gladiator for the Dome of Doom. Beats his opponents, asks for everyone to be free.

17. Scotsman's wife kidnapped. Jack and Scott rescue her, but are overwhelmed by the robots. Master of robots calls her fat, she goes berserk and kills everything.

18. Scientist makes 8 robots, trains them to kill Jack, powers them through Haku. Haku tells them to destroy scientist's city, so scientist gives Jack a power gauntlet to kill the robots. Jack kills 7/8, but then gauntlet runs out of power. Jack prays and gains power.

19. Jack visits his old city in ruins. Visions of the past. No action.

20. Jack is hopeless. 3 monks tell him to go to top of a very high mountain. Near the summit, Jack is about to abandon, but realizes he has to go on. He makes it to the top, and regains confidence in his quest.

21.Medieval village tormented by periodic stench. Jack realizes stench comes from dragon farts, goes inside dragon bowels, finds out baby dragon is spitting fire inside.

22. Haku asks 4 legendary hunters to capture Jack. They manage it, but Jack was their best hunt ever, so they grant him freedom instead.

23. Demon, minion of Haku, steals warrior souls and spawns them at will. Jack beats the souls, but the demon keeps spawning them. Only solution: Jack goes inside the demon and frees the souls.

24. Alice in Wonderland-like world. Jack takes a bath, gets his sword stolen by a white rabbit. Jack runs after white rabbit throughout the town, finds out it's only a girl with white-rabbit-looking backpack. She wanted to sell sword for money.

25. 300-like episode. Spartans fight against massive army. Jack shows them secret path to mastermind's citadel, they beat the boss, end of war.

26. Transformers-like robots/motorcycles break Jack's wooden sandals. He tries tennis shoes, heels, goth spiky black shoes, but he has problems with all of them when he tries to beat the robots. He has wooden sandals made in Asian shop, and beats them.

27. Jack stumbles into grumpy wizard in the street. Wizard turns him into a chicken. Jack gets captured, and his master enrolls him into underground coq fights against toxic critters and mini robots. One day, master and Jack walk in the street, master bumps into the wizard. Master turned into chicken, Jack back to human.

28. Graveyard, Haku-controlled zombies, and banshee. Banshee gets control of the sword, Haku appears, stabs Jack with it, but fails: the sword can only do good.

29. Techno music coming from the woods mesmerizes village kids. Jack discovers evil DJ plays Haku songs, defeats him, and frees kids.

30. A Western of robots. Big strong cowboy and his Cancan wife team up to capture Jack. They nearly succeed, but she ends up betraying her husband, and Jack beats both.

31. Haku awakens the 3 minions of Seth. To beat them, need to assemble together 3 pieces of scarab. While pursued by the minions, Jack finds the scarabs and summons Thot, who kills the minions.

32. Magic lake where people can't swim, only sink. Loch Ness monster transports Jack to the island. Series of monsters transport Jack until a time-travel portal. A buffed human guardian protects the portal, awaiting the Chosen One. The guardian wins because the Chosen One is not Jack right now, but Jack in the future.

33. Big, goofy, and peaceful creature follows Jack. When Jack finds time travel jewel, the creature eats it. Jack is furious, but creature still follows. 4 robots come and beat Jack. The creature goes berserk, transforms into something horrible, and kills the robots.

34. Haku disguised as hermit asks Jack for the 3 gems of Chronos, ie the power to travel in time. One temple for each gem. When Jack picks the first gem from its pedestal, water floods the room from a small orifice. Solution: use gem to plug the orifice. Second temple is wind-based. Third gem is inside a glass greenhouse that only opens at sunrise. Soon, the sun rays go through the glass and threaten to burn Jack. Solution: use gem to deflect sun rays and break the glass.

35. Spooky mansion. Jack gets flashes of the past: a dragon/wolf demon possessed ate the soul of the house's inhabitants. The demon eats Jack's soul too, but Jack beats him inside. Very few words are spoken.

36. Giant spiral tower has time travel portal on the top. Jack goes with 2 Shaolin monk friends. Thousands of stone warriors attack them on the way. When they find the portal, the monks are outnumbered and tell Jack to go, but he can't let them die. The portal disappears.

37. Jack wants to steal the jewel inside a pyramid filled with traps. Another thief, using spy tools, enters the pyramid at the same time. They go their own ways, pass similar traps in different ways. When they pick the jewel, robots appear, they are outnumbered, the thief leaves Jack behind, but regrets, goes back, and saves him. Outside, they argue so much over the jewel that they break it.

38. Haku hires ninja. Ninja lures Jack inside a hollow tower filled with wooden planks. Ninja hides in the shade of the planks, Jack hides in the light. All is black or white. As the sun sets, Jack loses ground. Solution: Jack blinds ninja with his sword and kill him by throwing his sword at him.

39. Mondobot, a 100 meter-tall robot, used to protect a city of robots. After it started to attack the city, the citizens tell Jack to find a legendary Power Ranger-like megabot hidden underwater. Jack goes inside, becomes the megabot. Mondobot fires guns at megabot, useless. They sword-fight until both swords break. Then fist fight, Jack wins.

40. Inn. Funky groovy Black guy says he is the real Jack. He duels Jack, they go outside, Jack asks to use bamboo swords, Jack wins. Haku robots show up, Jack kills them. They re-assemble behind Jack's back, the impostor sees it and warns Jack, who kills them again, and thanks the impostor.

41 and 42. Haku's origins. 3 original gods fought evil in space, but did not clean well. Tiny part falls on Earth, a big black pool of goo, passive but evil. Brave Asian emperor uses magic potion to clean the pool, but it only transforms into Haku. The gods send a horse to ride the emperor to a magic forge. At the forge, they make a sword able to kill Haku, and banish Haku in the ground.

43 and 44. Scotsman on a steamboat meets a waiter who looks like Jack, but denies he is Jack. To make him remember, he makes the lookalike fight bounty hunters, but he is weak and loses. Scotsman abandons, until singing sirens lure the ship, its crew, and Jack to their island. They hypnotize everyone. Scotsman on the ship is immune, says "his wife sings better", and plays the bagpipe to wake up everyone, including Jack.

45. Haku was sick, and unknowingly gave Jack his virus. Jack becomes angry and evil, and is neutralized by monks. While locked at the monastery, he fights Haku inside himself.

46. 5 bounty hunters, with their own idiosyncrasies, gather at a place rumored to have Jack. They team up and make a complex plan to ambush him. When Jack shows up, Jack is too fast/strong and ruins all parts of their plans.

47. Aliens land on Earth, need their ship fixed. Haku captures them while Jack was watching. Jack frees them.

48. Haku asks for a duel against Jack without his sword. Jack agrees only if 1) no shape shifting, 2) no minions, 3) no super power. Jack beats Haku, so Haku cheats and changes shape. Jack goes to pick up his sword, but a minion grabs it before him. Jack knew Haku would cheat, so he hid thousands of copies of his sword around. Haku loses his temper and leaves.

49. Summer: Jack hallucinates in the desert heat, fights shadows, gets tired. He concentrates on his qi and finds a real oasis. Fall: mad scientist makes potion to kill Jack, pours it into a well. Jack shows up, cautious, but only pretends to drink. Mad scientist does not understand, drinks, and dies. Winter: grim blacksmiths forge epic sword in a long process, and give it to their champion to beat Jack. First hit, Jack cuts the sword in two. Spring: a spirit lulls Jack to rest and sleep. He agrees, but keeps thinking of Haku. The spirit tries to force him to stay, Jack fights and beats it.

50. Robot with emotion chip, in love with his dog "Loulou, sweet thing". Haku kidnaps the dog, forces robot to attack Jack. He gets beaten by Jack, but asks him to take care of Loulou.

51. Jack as a child, sent to an African tribe to learn their martial arts. Makes friend with chief's child. One day, villagers imprisoned by evil men paid by Haku. Jack learns how their weird weapon works, and frees the villagers. Then the villagers beat the evil men.

52. Jack finds a baby without his mother. Baby whines, so Jack has to find milk, cure the kid, and fight off trolls who want to eat it. The baby's eyes see everything. When the mother comes, the baby has Jack's serious look on his face.

The Dropbox Space Race

noreply@blogger.com (gentimouton) — Tue, 10 Mar 2015 00:27:00 +0000

The Dropbox Space Race program ended on March 4 2015. This was a marketing event to get as many students as possible to install and use Dropbox. The more students of your university sign up, the more space Dropbox will give you. It was quite effective: the National University of Singapore had more than 20k students enroll, TU Delft 13k, MIT 11k, and so on. While the help page currently says that the extra space goes away after 2 years, it was not as clear at the time. So Dropbox sent an email early March 2015, titled Your Dropbox Space Race promotion has now expired, get Dropbox Pro.

I think the Space Race was a great marketing idea when it launched. It promoted school spirit as students united for a common cause. It was framed as a challenge. And it was free and fun. But Dropbox is pulling the space away, and I think it is a terrible move for several reasons. First, Dropbox gave a toy to the kids, and is taking it back just to make money. Students are realizing that the whole Space Race was a marketing scam. It was too free to be true. Second, I expect that most people were not even filling half of their Dropbox. What is the point of taking away something people are not even using? Third, the Space Race only involves cheap and broke students. How many are actually going to pay, rather than grudgingly shrink their Dropbox to fit 4 GB? And last, what does 8 GB of space cost Dropbox? Google offers 15GB for free, so if space really mattered to me, nothing prevents me from switching from Dropbox to Google Drive. I am giving a try to Copy, Barracuda Network's version of Dropbox, offering 20 GB for free. I don't need 20 GB, but Dropbox's move made me try others. My research lab switched to BTSync, with our own servers backing up our data.

So the Dropbox Space Race is like cheap wine: exciting at first, but bitter at the end.

Hearthstone

noreply@blogger.com (gentimouton) — Sat, 28 Feb 2015 00:35:00 +0000

Hearthstone is a trading card game released by Blizzard in March 2014. It's available on PC, Mac, iOS, Android, and more platforms because it is built on top of Unity. Hearthstone had 25 million registered players in January 2015. If you come from a traditional pay-to-play sector of the game industry, you could say that Hearthstone has twice more players than World of Warcraft, and be impressed. But if you come from the free-to-play sector of the game industry, you know this number means nothing: the game is free, so players will eventually try it out. In the mobile F2P market, nobody reports "registered players": what matters is the number of monthly users, and the average revenue per user. In fact, if we look at Hearthstone as a free-to-play mobile game, it is an outlier in several ways. And it's not necessarily a bad thing.

First, the business model. Players can earn coins, a soft currency in the game, by completing daily quests. One new quest becomes available per day, each quest takes 1-2 hours to complete, and grants 40-60 coins. Players can also get coins by winning games against other players. The amount is much smaller though: 10 coins every 3 wins (a match takes 10-15 minutes). Each pack of five cards cost 100 coins or $1-$1.5 if bought with real money. Cards can also be crafted from dust, another in-game currency. Dust can be acquired (nearly) only from cards bought with real money. So the game is free to play, but with 5 new cards roughly every 2 days, non-payers will find it excruciatingly slow to progress compared to other free-to-play games.

Second, mudflation. Some cards from the Gnome vs Goblin expansion set clearly outclass cards from the base set. For example, the Murloc Raider from the base set, has 2 attack, 1 HP, and costs 1 mana. The Clockwork Gnome from the expansion has the same stats, AND gives a 1-cost utility card to its owner when killed. I admit that this kind of outclassing also happened between the free cards and paid cards from the base set. For example, the River Crocolisk from the free base set is outclassed by the Amani Berserker and the Bloodsail Raider (both paid/crafted cards). So balance-wise, it's as if the set of paid cards was the first expansion, and Gnome vs Goblin cards the second. Either way, non-payers can't compete against players who purchase (expansion) cards.

Last, the daily quests. Blizzard first came up with daily quests in World of Warcraft, 6-7 years ago, to give people things to do while waiting for the next content patch. They had removed the cap of daily quests completable per day, and realized that "that really leads to burn out". Mobile free-to-play games started using daily quests as a way to retain players, 3-4 years ago. And now, Blizzard is back to using daily quests to retain players. But this time, they cap the quests to 3. Compare this to the dozens of achievements in Clash of Clans, where there's always something to look ahead for. Players could play hours at a time to push for Clash of Clans achievements. But in Hearthstone, quests run out quickly, so there is little reason for players to stay longer than necessary (except maybe leveling up or winning, but the rewards are so much lower than daily quests that they don't seem worth it). I also suspect that players eventually get tired of doing the same quests again and again. Cleaning up Naxxramas brings a good change of pace, and has very interesting mechanics, but each aisle cost 700 coins, so it only happens once every 2 weeks. Too bad ... So daily quests: somewhat good for day-to-day retention, but probably bad for session duration.

The search bar of Firefox 34

noreply@blogger.com (gentimouton) — Mon, 15 Dec 2014 20:29:00 +0000

When I use my web browser, I am usually doing a search. I am rarely typing a URL from memory. Also, I try doing everything through my keyboard. Using my mouse means thousands of back-and-forths with my right hand every day, which cost me time and energy. And sometimes I have to look at the mouse to grab it, which makes me lose my focus on the things I was doing on the screen. For what I do, all-keyboard is better.

Up to Firefox 33, my typical web-search steps were: 1) alt-tab to web browser, 2) ctrl-K to focus on the search bar, 3) ctrl-down to select the appropriate search engine, 4) type query and enter. Step 3) is a power user step. Its goal is to save time by not using the mouse and skipping a web page load. For example, I want to know who Seth Green is. I could run the search through Google or DuckDuckGo, and then click the Wikipedia link (usually in the top 3 results). But if I select Wikipedia as my search engine, I directly land on the page for Seth Green. So ctrl-down saves me a page load and a mouse click. Some users even have more than 30 engines!

In their new search interface, called Find it Faster, FF34 basically replaced ctrl-down by a mouse click on tiny buttons. FiF saves me a page load, but it's at the cost of a mouse click. Below is a GIF demonstrating the new search feature.

Average users do not switch search engines - they always use the default one. So FiF is a feature targeted to power users, and yet it apparently forces them to use their mouse. Obviously, the feature has annoyed many users, including me.

There are two solutions. A first solution is rejecting the change: go to about:config, and switch browser.search.showOneOffButtons to false. Another solution is learning the change: the search steps used to be 3) ctrl-down, then 4) type query and enter. Now the steps are 3) type query, then 4) press tab to switch search engines, and enter. This new process is not as good as the old one: switching search engine after having typed, rather than before, loses the benefit from autocomplete/search suggestions anymore. Anyway, Mozilla should emphasize on their FiF release page that tab replaces ctrl-down.

Edit 3/17/2015: to disable it, go to about:config, and turn

browser.search.showOneOffButtons

to false.

Diablo's randomness: competition vs variety

noreply@blogger.com (gentimouton) — Mon, 17 Nov 2014 02:27:00 +0000

In Diablo 3, randomness is everywhere: in item rolls, maps, monster types, critical hit chance, and more. This randomness bothers competitive players. Greater Rifts (GR) are the platform where competition takes place. GR are random in several ways: their maps are generated randomly, their monsters picked randomly, and the monster density also happens to be random. Therefore, ranking high on the leaderboards is mostly a matter of luck, not skill.

Blizzard probably launched the first season as a sort of test drive. They figured players would still find some exploits during season 1. I think Blizzard learned many lessons from season 1. I thought one of them was that they should level out, or even remove, the sources of randomness in GR. For example, I really expected that they would remove pylons from GR. Others expected the same. But Blizzard has decided to keep pylons inside GR for season 2. I was bewildered: why keep a luck-based mechanic in a competitive setting? I can now see at least two reasons.

One reason is that Diablo 3 is not about player skill, but about grinding. I think looting a full set of decently-rolled gear takes around 50 hours. Then the game is all about looting better-rolled gear and acquiring decently-rolled ultra-rare gear such as Tasker and Theo or Wand of Woh (both below 0.2% chance from Kadala). Crafting a good Hellfire Amulet, another end-game yet crucial piece of equipment, can take months. The hardcore players who compete on the leaderboards have acquired all this gear. While they may object to the contrary, they love grinding, or they would never have obtained such great gear. Thus re-rolling GR for slow and benign Risen Deads instead of fast and dangerous Winged Assassins may be less boring to them than it is to me.

Another reason for keeping randomness in a competitive setting is variety. The developers admit that they use randomness in Diablo III to increase the replayability, Greater Rifts included. Pylons can be a hell of a lot of fun to encounter in game, and that’s one of the big reasons we added them to Greater Rifts. The great majority of players do not compete seriously for the leaderboards, so they actually really enjoy the occasional Conduit Pylon in GR. Moreover, even competitive players may become bored if the GR were completely standardized: they would always know where to go, which monsters to avoid, and so on.

In short, Blizzard is probably right to keep pylons inside GR, but they should definitely look at 1) leveling out monster density across GR, and 2) leaderboards that measure player skill by their ability to deal with randomness.

Network Algorithmics by Varghese

noreply@blogger.com (gentimouton) — Wed, 15 Oct 2014 19:30:00 +0000

I skimmed Network Algorithmics by George Varghese (2005). This book presents common tricks used at the OS, hardware, and architecture levels to prevent network bottlenecks. Here are 15 principles listed on the first page.

Number	Principle	Example
1	Avoid obvious waste	Zero-copy interfaces
2	Shift computation in time
2a	Precompute	Application device channels
2b	Evaluate lazily	Copy-on-write
2c	Share expenses, batch	Integrated layer processing
3	Relax system requirements
3a	Trade certainty for time	Stochastic fair queuing
3b	Trade accuracy for time	Switch load balancing
3c	Shift computation in space	IPv6 fragmentation
4	Leverage off system components
4a	Exploit locality	Locality-driven receiver
4b	Trade memory for speed	Processing, Lulea IP lookups
4c	Exploit existing hardware	Fast TCP checksum
5	Add hardware
5a	Use memory interleaving and pipelining	Pipelined IP lookups
5b	Use wide word parallelism	Shared memory switches
5c	Combine DRAM and SRAM effectively	Maintaining counters
6	Create efficient specialized routines	UDP checksums
7	Avoid unnecessary generality	Fbufs
8	Do not be tied to reference implementation	Upcalls
9	Pass hints in layer interfaces	Packet filters
10	Pass hints in protocol headers	Tag switching
11	Optimize the expected case	Header prediction
11a	Use caches	Fbufs
12	Add state for speed	Active virtual circuit list
12a	Compute incrementally	Recomputing CRCs
13	Optimize degrees of freedom	IP trie lookups
14	Use bucket sorting, bitmaps	Timing wheels
15	Create efficient data structures	Level-4 switching

Diablo 3 - item sets

noreply@blogger.com (gentimouton) — Tue, 14 Oct 2014 15:00:00 +0000

Modern item games like Diablo 3 (D3) use a mechanic called sets: when used together, certain items unlock particular bonuses. For example in D3, Litany of the Undaunted increases attack speed, The Wailing Host increases crit chance, and used together they give 15% extra gold from monsters. Item sets is an old mechanic - the Diablo 2 expansion already had some in 2001.

Sets in D3 are a great mechanic for at least two reasons. First, sets let developers encourage the use of certain skills. Since the bonuses from set items nearly always provide more damage than regular non-set items, players use them. For example, the Marauder set for Demon Hunters requires the use of sentries, a skill that would not be used otherwise because its AI for picking a target is unpredictable. Second, set items are a great mechanic also because they give players a goal. When I dropped my first set item and saw the set bonuses, I immediately wanted other items in the set.

Sudden increase in power

End-game starts after reaching level 70. Reaching level 70 by yourself takes roughly 15 hours. Difficulty from then on can be measured by the Greater Rift (GR) level your character can reach. Set bonuses are so powerful that they make your character jump multiple GR levels at once. For example, going from 5 set items to 6 can double your character's effective damage or toughness, and make you reach 5 or 6 GR levels higher. This explains why the Ring of Royal Grandeur, which reduces the number of items needed for set bonuses by 1, pretty much a wild-card for all your sets, is such a game-changer. These sudden increases in power sometimes surprise players, but I think each bump makes them suddenly feel very powerful. Interestingly, back in 2013, sets used to be as good as non-set legendary items.

Vague descriptions or hidden mechanics?

The descriptions of D3 set bonuses are often vague, and require the player to check the forums and Youtube videos for details. Here are two examples.

Marauder set

This is a Demon Hunter set. The 2-piece bonus is straightforward: it gives 500 dexterity (on top of the approximately 500 dexterity already contributed by each set piece).

The 4-piece bonus makes the Companion skill call all possible companions (instead of only one). Do passive effects from the Companion skill (e.g. the boar increases life regeneration) apply as well? And do all active effects trigger when I use the skill? The answers are not written in the description, but people figure it out quickly by trying.

The 6-piece bonus reads: Sentries cast your equipped Hatred spenders. After trying it out, I realized that sentries have a different rate of fire for each spender: Cluster Arrow (massive area damage) seems to happen only every 5 shots, whereas Elemental Arrow (small multi-target damage) the rest of the time. Looking at high-level Demon Hunters, most wear Tasker and Theo, which increases the attack speed of your pets by 40-50%. Are sentries pets? (Yes!) And how can I make my sentries use Cluster Arrow more often? (You can't!) Theorycrafters figured it all out by analyzing game frames one by one and sharing their findings. But is the average player supposed to read the forum to improve their character?

Zunimassa set

This is a Witch Doctor set. The 2-piece bonus gives 250 intelligence and grants 30 Mana per Kill. Is it only when my character performs the killing blow on a monster? Does it also work when it's one of my pets? Does it also work when it's another player?

The 4-piece bonus reads: Your Fetish Army (FA) lasts until they die. This is straightforward, and it made me think about the passive skill Fetish Sycophants (FS). FS seems to combo well with FA: When you hit enemies with your spells, you have up to a 10% chance to summon a dagger-wielding Fetish to fight by your side for 60 seconds. There are several problems with this apparent FA-FS synergy.

First, why the up to? What makes the rate be less than 10%? That is where theorycraft comes to the rescue. The community found out that one can have at most 15 active FS at the same time. So the rate of FS trigger is 10% until 15, at which point it becomes 0%. The description of FS should also mention this cap of 15.

A second problem is the easy confusion between the two types of fetishes. 1) Witch Doctors can have many pets: a Gargantuan, zombie dogs, FA fetishes, FS fetishes, and mimics. FA and FS are both fetishes, so intuitively, they must benefit from the same bonuses. 2) Why excluding FS from the 4-piece bonus when the effect from the Carnevil helm applies to both FA and FS? 3) The distinction between FA and FS is not for game balance: in practice, it's very easy to maintain 15 FS active all the time by speeding through monsters.

Why so vague?

I can see several reasons:

Practicality: the developers want to be able to modify the bonus (through hotfix or patch) without modifying the description.
Brevity: a precise description may require too much space in the item tooltip.
Practice: figuring it out by trial is more visceral than by just reading the description.
Theorycraft: explaining everything spoils the fun of theorycrafters.

Uselessness, sub-optimality, and combinatorics

Some sets are clearly underpowered compared to others. The Witch Doctor Invoker set and the Demon Hunter Shadow set are only useful when your character gets hit. Sadly, in D3, the best defense is offense: the goal is to kill monsters quickly enough that they don't kill you. Therefore these sets end up never being used (except the 2-piece Shadow set in hardcore mode, maybe?).

The Natalya set is not useless, but rather suboptimal. Both the 2-piece and 3-piece bonuses increase damage slightly and enhance mobility (more discipline means more Vaulting). The 4-piece bonus reduces the cooldown of Rain of Vengeance by 2 seconds for each enemy you kill. RoV has a base cooldown of 30 seconds, and does 1000% area damage for 5 seconds, so the set seems very interesting. In practice however, it is difficult to keep monsters grouped in an area for 5 seconds. So while some players use the 2- and 3-piece bonus, nobody cares about the 4-piece bonus. I wonder if the set would be more used if the cooldown was reduced by 2 seconds for every enemy hit (instead of killed).

ArcheAge boasts 120 classes, but it's only because players can pick 3 skill trees among 10, ie C(10,3) = 120 different combinations of skill trees. I don't think that all combinations are efficient, but ArcheAge achieves such diversity simply by leveraging combinatorics on 10 coherent sets of skills. In D3, a player using a Demon Hunter can pick 6 active skills among 24, so that's a total of C(24,6) = 134k different builds. Add to this that each active skill has 4-5 runes, and that there are also another 4 passive skills (5 if we count the Hellfire Amulet) to pick among 18. That's billions of combinations! Yet the only sustainable Demon Hunter builds actually played are minor variations around the same 6 skills. That is because the Marauder set forces players to pick these skills. Moreover, I really liked combining multiple 3- and 4-piece sets together, but the 6-piece Marauder took all the spots. I wish D3 had 1) more 4-piece sets and fewer 6-piece sets, and 2) combinations between sets, not just between sets and legendary items (e.g. Marauder and Tasker and Theo)

Diablo 3 - the item game

noreply@blogger.com (gentimouton) — Tue, 14 Oct 2014 00:48:00 +0000

In item games, the main goal of players is to continuously upgrade their gear. Diablo 3 (D3) is the perfect example: kill monsters in order to drop better gear in order to kill monsters faster. Bungie just released Destiny, an item-game FPS budgeted with half a billion dollars. Yet Destiny could learn from Diablo 3. So here are some thoughts about the item game in D3.

Prevent farming ...

In D3, like in D2, the drops are completely random: with a few exceptions, nearly any item can drop from any monster or wreckable object (e.g. jars). The odds are just higher for harder monsters, and way lower for wreckable objects. The exact drop rates are secret (except the 10% legendary drop rate from Kadala). This secrecy has led to various rumors and tinfoil hat theories about how loot can be influenced.

D3 has, or used to have, farming spots such as the Decaying Crypt, but they were mostly for XP, not for drops. In D3, farming boss monsters actually brings fewer drops than farming normal or elite monsters. This contrasts with Diablo 2, where players were grinding bosses like Baal or Diablo for XP and loot. So in a way, the grind in D3 is less boring than in D2.

... Yet allow farming

As of October 2014, there are 2 exceptions to what I just wrote: 1) bounty rewards like RoRG or Helltrapper, and 2) Hellfire Amulet.

The RoRG was introduced in February 2014. It is a mandatory item to reach the game's highest difficulty levels. Players have to camp Act-1 bounties to get one with good rolls. To farm as quickly as possible, players join co-op games to split farm: instead of spending 15-20 minutes completing the 5 bounties together, they each complete a bounty in 5 minutes. I am surprised that the developers did not see it coming: split farming is very clearly not how we want players to play the game. Yet nearly a year later, they still have not changed the bounty system.

The Hellfire Amulet is not as mandatory compared to the RoRG. But its bonus is so useful that all of the top players have it. Farming it is somewhat more fun than farming for RoRG, since it is a quest in itself: a) hunt for the 4 Keywardens on the game's largest maps to obtain 4 keys, b) combine the 4 different keys into a portal, c) kill 2 super bosses at once, a somewhat more difficult task than the Keywarden hunt, and d) combine 4 super bosses' loots to obtain a Hellfire Amulet.

The Reaper of Souls expansion

From launch in May 2012 until the retirement of the Auction House (AH) in February 2014, players were mostly buying their gear from the AH, and sometimes grind-crafting it. They nearly never dropped it themselves. Legendary weapons had 7-8 affixes. After the AH retired, Loot 2.0 arrived, and the expansion Reaper of Souls (RoS) shortly after that. Legendary weapons now have 4 primary and 2 secondary affixes. Secondary affixes do not matter much (e.g. more XP when killing a monster), so RoS drastically reduced the item entropy.

The expansion also reminded me of Blizzard's somewhat elegant solution to a common MMO problem. Most MMOs in the early 2000s had the same problem: players who have been playing for a year have too much of a head start compared to players who have been playing for 3 months. New players are hopeless, especially in PvP situations. World of Warcraft solved this problem with what I call expansion gating: WoW vanilla capped the character level at 60 and item level at 92. Until the first expansion came out to increase these two caps, players were gated there. The advantage of expansion gating is that it gives the same chance to old and new players. The main drawback (if any) is mudflation. Diablo 3 is no different: level-70 items have twice more DPS than level-60 items. Thus when the expansion launched, players threw away all the gear they had acquired before.

Few links to other end-game activities

Item games have a great loop, but it is not enough in itself. D3 launched in May 2012. The Auction House (AH) launched in May 2012 too, so players could play two games in one: the action RPG and the auction game. Note that you did not need to play the aRPG to play the auction game, but you did need to buy gear off the AH to play the aRPG well. Had it been the opposite, I think the game would have been much better.

In July 2012, the developers realized that the item hunt is just not enough for a long-term sustainable end-game. Since launch, the game also allowed players to hunt for achievements and start new characters (in softcore or hardcore). In August 2012, the developers added the leveling up grind through 100 Paragon levels. Every Paragon level increased the chance to drop an item and the amount of gold dropped by 3%. In February 2014, Paragon levels became infinite, and the 3% bonus was removed. Clans and communities were also added in February 2014. Since August 2014, players can compete on the greater rift leaderboards, and start new seasonal characters (in softcore or hardcore). Interestingly, the item game is completely independent of all other end-game activities (except the AH and the original 100 Paragon levels increasing magic find and gold find). In other words, the item game of Reaper of Souls could be directly copied into another game without having to also copy the other activities.

Ken Lobb FDG 2014 keynote

noreply@blogger.com (gentimouton) — Thu, 09 Oct 2014 02:41:00 +0000

Ken Lobb designed Golden Eye and Killer Instinct in the 90s. Here are notes from a keynote he gave at the FDG 2014 conference.

Having an extensive knowledge of games is mandatory for game designers, because they provide a common vocabulary to talk about games.

In the late 80s, teams rolled their own tools. Nowadays, AAA teams still have the not created here problem and waste a lot of time reinventing the wheel. That's why indies using Unity or Unreal can save on costs and take a bite at AAA.

The most important tool in game development is the game build, because it is how the game improves, little by little. Next comes the schedule, ie what to do next. Finally comes the spec and docs, because they change all the time. Microsoft has the process mastered. In fact, Microsoft is too good at planning: they always ship what they speced, and not exactly what they should create. The industry in general, and Microsoft in particular, sign games that cost way too much money.

Difficulty: games have shifted from lose vs win, to win vs big win vs epic win. now in call of duty, high kd ratio is winning. dying is not too bad. before in golden eye, die means restart whole 10min level. now, focus on positive reinforcement rather than punishment.

Major game design issues:

Tutorials are hard to build right. Should players be reminded of mechanics they may already know, or should they instead be taught from scratch? The Zelda series have great tutorial design: they simply give the player the tool, and teach by giving more and more difficult challenges that require using that tool. Achievements can also encourage a particular behavior.
Cheating is OK. 90% of Xbox players are also on a second device when they play. Players use Youtube, watch Twitch, and look for cheats and FAQs all the time. Procedurally-generated or randomized content can curb this practice down, but a real solution may involve the game itself showing tips or videos from the players who passed an obstacle to those who are stuck.
Making a game noticed on app stores/platforms is difficult. Advertising and charts do not target particular players. Word of mouth is more effective, but how does it start? Maybe app stores could recommend games to hardcore players, which would trickle them down to their friends? [This may have an answer: according to Wooga, it takes $250k to reach the first spot on the App Store]

Diablo 3 - Randomized content

noreply@blogger.com (gentimouton) — Tue, 07 Oct 2014 17:27:00 +0000

A lot of game content in Diablo 3 is determined randomly. Arguably, more randomness means more diverse content and therefore players less likely to become bored by repetition. But randomness also has drawbacks.

Maps

Maps are generated somewhat procedurally. Some elements like the map borders remain constant, but events and dungeon entrances are picked randomly among a pool and placed randomly in predetermined places.

Maps like The Den of the Fallen sometimes have loops, which is annoying: players kill monsters on their way, but when they realize they have been looping around, they go back on their way without any monsters to kill. It is a waste of time. A solution could involve using heuristics to prevent loops.

A Greater Rift (GR) is a dungeon in which players race against time. The higher the level of a GR, the tougher its monsters. GR is a competitive activity: leaderboards show the teams who achieved the highest GR levels. Problem: the GR map is picked randomly; sometimes it is a maze, sometimes it is linear, and sometimes it has loops. The randomness does not make for a fair competition. One solution would be to remove maze maps from the selection. Another solution would involve keeping the map and monsters constant, and make one leaderboard per map. It would be pretty much like a racing game.

Elite affixes

Elite monsters can have up to 5 affixes. Affixes have 3 categories: crowd-control such as Vortex, defensive such as Extra health, or offensive such as Desecrator. These affixes are picked randomly, with a couple heuristics making sure that an elite can have at most one crowd-control affix and at most one defensive affix. Some affixes such as Invulnerable Minions were so annoying that they were removed from the game altogether.

Still, some combinations remain more deadly than others. For example, elites combining Molten (they burn where they walk on), Fast, and Horde (create 8-10 Molten and Fast minions) are the bane of melee characters.

Gear

In the original Diablo 3 (also known as D3v for Diablo 3 vanilla), loots were completely random. For example, a Wizard could drop a mace only Barbarians can use. Enters the Auction House (AH for short): the Wizard sells the mace on the AH and, with the money received for it, buys a better wand from the AH. Trading through the AH worked well from launch in May 2012 until August 2012 when the designers realized that the AH can short circuit the natural pace of item drops, making the game feel less rewarding for some players. Indeed, players could obtain second-best gear in only a couple days, play for a week, get bored for not progressing, and leave the game. Conclusion: completely-random loot with an AH for trading does not work.

Loot 2.0 landed in the game just before the Reaper of Souls expansion. Loot 2.0 has 3 parts: 1) little to no exchange between players (to prevent gold farming), and no AH, 2) loot is targeted to the player, ie Wizards only drop Wizard gear, and 3) the Mystic lets the player reroll an attribute on any piece of gear. Six months after the release of the expansion, this has been holding fine.

Improving the end-game of social strategy games

noreply@blogger.com (gentimouton) — Thu, 04 Sep 2014 03:52:00 +0000

Improving the end-game of social strategy games

I removed Clash of Clans (CoC) from my iPad on August 20, 2014. The game had just reached two years old, and I had been playing it since February 2013. I played very actively (2-3 hours per day on average) until December 2013, then considerably slowed down (1 hour per week).

No new content

I think I slowed down, and eventually stopped playing mostly because no significantly new content was introduced. New content mattered a lot to me because I had reached Town Hall 10, the very end of the game, for many months. So far, the game has received four updates in 2014.

Month	Description
January	Introduced Hero abilities, which are not really a new gameplay feature, but rather a design fix to encourage players to use and upgrade their heroes. Great, and perhaps even necessary, but no impact on battle strategy or base design.
April	Introduced Clan Wars, a feature asked by players since the game came out. My clan was very excited, but we stopped Clan Wars after a couple weeks. We realized that the match-making algorithm alternated pairing our clan against once a much stronger clan, once a moderately weaker clan. Clan Wars require a lot of time and in-game resources, so we kept asking for enemy clans, but only attacked when we were sure to win. After a few weeks, we realized the Clan Wars rewards were not worth the frustration, so we stopped match-making.
May	Mostly usability tweaks.
July	Improved Hero abilities. Once again, this was more a design fix to encourage the use and upgrading of Heroes than a new feature.

Moreover, in these four updates, the Hog Rider received three nerfs, but my base still got trampled by mass-hog armies. (Yes, anti-hog base designs exist, but these designs are very vulnerable to air attacks). The Valkyrie was buffed twice, but it still was not enough to make her useful for her cost. To sum up the last 8 months, no new mechanic, be it a unit or a tower, was introduced, and I did not find the balance tweaks adequate.

Lessons for social strategy games

Troop synergies

The game was released with 10 basic units that make sense when used together. For example, the Giants are slow and target defenses so that the Healer can follow them without being hit. These synergies are expected: the team had time to iterate and polish before launch. But introducing new troops after launch is tricky: the new troops must 1) have an interesting gameplay element, 2) complement existing troops, and 3) keep existing troops useful.

The Minion is a perfect example: it is cheap and flying. This makes it a great complement for farming with Barbarians and Archers (called the BAM strategy). It is also great for high-level PvP when paired with Balloons (Balloonion strategy). And since it costs dark elixir and has low HP, it can't be used by itself.

The pricey Golem is another great example: it synergizes well with Wizards and Pekkas (GoWiWi strategy), which are necessary troops in high-level PvP. The Golem's production stats are perfect: 45 minutes to make, and a cost of 2.5 hours-worth of dark elixir, which is the same as Pekka. The Golem was clearly designed to be trained in parallel of Pekka. Plus Supercell must have made a lot of money from players gemming it!

On the other hand, the moderately expensive wall-jumping Hog Rider does not complement any other troop. Neither does the Valkyrie. Interesting ideas, but no synergy! Supercell keeps trying to fix them, so they may have realized that. Or maybe Supercell abandoned them completely, and has been working on more troops, such as the Spider, Centaur, or Yeti, which have not been released yet, but were leaked in July 2014.

More things to do in the end game

As the Town Hall levels go by, so does the average duration of building upgrades. For example, upgrades take 3-10 hours at TH3, 1-3 days at TH6, and 7-14 days at TH10. By TH10, the player should have 5 Builders, so the average time between two building upgrades is still 2-3 days. During these 2-3 days, players come back to the game only because their troops are ready for battle, not because they have something to do with their base. But by TH10, players have spent months being progressively conditioned to come back for their troops and not their base. So they still come back, but more and more reluctantly, since the rewards are less and less frequent. At some point, they unlearn the habit of coming back to play: what's the point when nothing seems to be happening? They eventually stop playing.

Possible solutions involve shortening upgrade times or providing more builders, but both may seem like Supercell would lose money. The game should at least give players things to do with their buildings (beyond collecting resources twice a day). The Bomb very short upgrade times have been a step in that direction. A crafting system like in Monster Legacy, or Angry Birds Epic, but applied to strengthening buildings, or increasing towers' rate of fire, may increase the game's lifespan even more.

List of tower defense games

noreply@blogger.com (gentimouton) — Tue, 02 Sep 2014 01:18:00 +0000

I had started to compile a list of tower defense games a couple years ago, but never managed to finish it. The goals were to 1) list the basic gameplay elements that define the tower defense genre, 2) spot original gameplay elements that have made the genre progress, and 3) track the history of the genre, much like what has been done for shmups.

Name and URL	Release date	Image
Players	Platform
Bosses	Path
Comments
Backyard Monsters	early 2011
single player + Facebook friends	Flash on Facebook
Champion units never die	Free path
Receive and donate monsters from/to your Facebook friends. Send your troops against the base of another player to steal their resources. Half-cloned by Clash of Clans in 2012. By Casual Collective (now Kixeye).
Bubble Tank Defense	2009
Single player	Flash
Has bosses	Free path
Mega towers are a combination of 4 adjacent normal towers. Tower upgrade is a tree: all towers start as basic towers, then they become zone, slow, specialize against ghost, etc.
Canyon Defense	2007
Single player	Flash
no	Fixed path
Unlock towers by completing missions such as building 15 towers or acquiring $1000. Developed by Russian studio Iriysoft.
CreepSmash	2008
2 to 4 players	Java
no	Fixed path
6 tower types, each with 4 upgrade levels. Player can specify AI for each tower (eg. target creeps with fewest HP). Receive income every 15 seconds. Increase income by 10% of the price of the creeps you send to your left neighbor. Receive creeps from your right neighbor. Green creeps regen life, white are immune to slow, blue are fast, red have lots of HP. Winning strategy: sell towers to send more creeps to increase your income faster than other players. Attack-defense gameplay. 4-player games, quickly turn into 2v2. Developed by a group of German students. The community is mostly German. open source.
Cursed Treasure	May 2010
single player	Flash
Has bosses	fixed path
3 families of towers: Demon (fire AoE or burn DoT), Orc (poison DoT or strong single-target attack), and Undead (freeze, fear, or slow). Towers gain XP and level up by attacking creeps. Tower effects change when they level up. Creeps are assassins (hide temporarily), crusaders (block damage), monks (heal other creeps), and other medieval characters. Each level completed grants the player XP used to level up to acquire and level up passive skills such as more gold at the start of the level, more gold per creep, reduced tower costs, or increased tower range or damage. Player can use 3 active skills: cut tree to place tower, temporarily double the fire rate of all towers, and splash meteor damage in an area. Developed by Russian studio Iriysoft.
DemonRift TD	Sep 2011
Single player	Flash
2 Bosses	Fixed Path
4 types of towers (swordsman, archer attacks long-range but not short-range, knight can chase fast enemies, and golem can stun and block up to 5 enemies). Command points are generated over time and when killing enemies, and are used to buy or upgrade units. Upgrades only add more creatures to a tower.
Desktop TD	release?
Single player	Flash
Has bosses	Free Path
Creeps go from top to bottom or from left to right. Mazing/juggling matters a lot. By Casual Collective (now Kixeye). Spawn, flying, and many other kinds of creeps.
Dungeon Defenders	2011
single-player	Unreal Engine
No bosses	Fixed Path
3D. Originally a showcase of the Unreal Engine. Source code available.
Flash Element TD	Feb 2007
Single-player	Flash
Has boss?	Fixed path
Start the first level with the 3 basic towers. Kill enemies to earn a bit of money to upgrade towers. At the end of each wave, earn 10% of your current money (+5% per skill point spent in a certain research skill). Earn Wood every 8-10 waves to unlock towers (earth, fire, water, and combo of the 3), skills, or increase your life. Also known as 3d tower defense.
Garden TD	release?
Single player	Flash
Has bosses	Fixed Path
Spitting cactus are overpowered, gnomes are useless.
Hold the holy pig	release?
Single player	Flash
Has bosses	Fixed Path
Towers are elemental: water slows down, earth is zone damage, fire attacks fast, plant poisons, wind only attacks flying creeps.
Mini tower defense	release?
Single player	Flash
No boss	Fixed path
Creeps are tanks, towers are lasers. Winning a level gives points that can be spent to increase tower powers.
Orcs must die	Oct 2011
Single player	XBLA and Windows
No Bosses	Path?
The game happens in 3d like a normal FPS. Creeps are Orcs. The player controls an FPS avatar with deadly skills and places traps and archers in that 3d-FPS view.
Plants versus Zombies	May 2009
Single player	Flash
One final boss	No path
Zombies come from the right towards your house on the left. 5-6 lines, zombies never change line (except when you use garlic). Every 5 levels, there's a mini game. Plants are cards acquired when winning levels. No shortcuts, just clicks. The money is sun, it falls from the sky and players have to click on it to collect it. Click fest at higher levels. Five worlds: backyard by day and by night, pool by day and by night, roof by day. Lots of Easter Eggs. Very easy to understand and play through.
Rat Poker	1998
Single player	Windows 95 and 98
No boss	Fixed path
Tower defense where creeps keep looping until you order them in series like Poker hands. The player has to organize rats in series resembling Poker series (three of a kind, six of a kind, rainbow series, etc.). Rats are walking and can be grabbed and released at specific locations.
Turett Tyranny	release?
Single player	Flash
No boss	Fixed path
Creeps HP keep increasing wave after wave. Kill creep to get money. Unlock, place, and upgrade towers with money. Towers have a size (e.g. 1x1 or 3x3) and can only be placed where they fit. Walls constrain towers' line of sight. There is friendly fire between towers, but you can pay to protect them from friendly fire.
Vector TD	release?
Single player	Flash
No boss	Fixed path
Usual basic TD. Graphics resemble CreepSmash. Steep learning curve.
Viking TD	Release?
Single player	Flash
No boss	Fixed Path
Creeps are boats of Vikings, towers are catapults and others. Towers are unlocked progressively in pseudo-quests such as "build 5 catapults to unlock the tree of wisdom" or "kill 3 Big Boats at once with a spell to get the Stone Head". By Russian studio Iriysoft.
VR defender Y3K	April 2007
Single Player	Flash
No boss	Fixed path
6 kinds of towers, such as normal, slow, and flame thrower. Tower appearances reflects its upgrade level. It's hard to figure out which strategy to use as ennemies just only keep having more HP wave after wave, cf also player feedback. Graphics resemble CreepSmash.
Wicked Defense	2007
Single Player	PC
Has bosses	Fixed path
Some creeps can buff other creeps. Spells can slow down or damage monsters. Weird graphics. 3D.

And a list of games I have not broken down yet.

Name	Comments
W3 mod
Colony Defense	The terrain is a sphere, which gives a Populous-like view of the planet.
Sol Survivor	3D, fancy graphics, multiplayer co-op
Garden Defense
Defense Grid	Matrix atmosphere, 3D, fancy-ish graphics, fixed path.
Fieldrunners	Resembles Desktop TD, old-school war atmosphere, kawaii 2D god-view graphics.
TriDefense	for iPhone
Besiegement	for iPhone
The Horde	1994, contender for first TD game around; Its FAQ says that The Horde currently deletes all other non-horde saved games in NVRAM when you save a game
Harvest: Massive Encounter	Creeps are aliens, towers are human. planet exploration atmosphere.
Protector	Towers are medieval characters.
Immortal Defence
Pixel Junk Monsters
Lock's Quest	DS game
Guns' n' Glory	For iOS. UI is intuitive, but moving units around looks clumsy. Video.
TowerMadness	iPad game, free placement, towers can be upgraded, creeps are aliens, lives are sheeps that you have to protect. 2 players can play at the same time on the same ipad, but there are no interactions between players (no co-op, no PVP).
Starship defense	DSi game, slow, fixed path, rubbing/touching creeps with stilet inflicts damage. towers can be positioned on slots on the wall or on the roof. Video.
Castle-Combat	Clone of Rampart, old game from 1990, possible origin of the TD genre.
Kajaani	in space
Lockdown TD	"lifting" system that lets you move towers temporarily and reposition them between waves
Pokemon TD	So successful it has a sequel.
Ninja vs Pirates
Starland	Multiplayer

And a list of lists of TD games, mostly Flash: