Monday 30 April 2012

What is strategy?

Sid Meier famously defined a good game as a series of interesting choices. What makes a choice interesting?

The human brain has the faculty for logical reasoning. It also has the ability to make decisions that cannot be made through logic - because they are too complex, because not all the relevant factors are explicitly known, because the the matter being decided is not logical. But it's honestly kind of terrible at it. We don't reliably make good decisions in life.

Strategy games can make use of this human faculty for irrational decision-making, and train it to do better. A game lasts for a short duration; by the end of the game the outcome of your decisions can be evaluated. In real life, the ramifications of a decision can take years to become apparent. Repeatedly applying a skill with prompt feedback on performance is an effective way to get better at it.

The game Mafia is a good example here. Playing it you learn to ignore the subjective biases that can affect your decisions but are irrelevant in the context of the game - e.g. whether someone is a persuasive speaker, attractive, or a personal friend. And if someone has a reasonable argument but everyone seems against them - well, remember that some players have a vested interest in opposing reasonable arguments, and pay attention. (Analogies to politics are easily made.)

Obviously games can also exercise logical reasoning, but this isn't so interesting to me. I find mathematics, science, philosophy, programming much more effective ways to practise logical thought, but playing games the most effective way to practise making decisions that are too complex to be decided through logical thought.

Additionally, the reasoning you can apply to games usually isn't very deep; it's just reduction to cases. The game of OX is easily solved; until you do it's possible to enjoy playing it, but as soon as you start mapping out all possible moves, it doesn't take much thought to realise that either player can always force a draw.
In any game of this form, the approach of "compute all possible moves" is applicable. In principle, you can just completely work out every response to every possible move. This formulation is sometimes used in the mathematical study of games - rather than a sequence of moves, games can be treated as having a single move where each player specifies their entire strategy at the start of the game. If a game can be reduced to a single move, why play at all?
In practise, of course, you usually can't do this. Checkers has been solved, but this took years of computation. More complex games cannot be expected to be completely solved. But even though you can't map them out to the end of the game, you can still look a few moves ahead and evaluate whether you'll end up in a better position. This is often the best way to play, and it's really really boring.
(Still, it's a very elegant way to implement hidden information in a game - instead of having it concealed on cards in your hand, it's buried right in plain sight behind an unreasonable amount of computation. Encrypted.)

So I'd define an interesting strategic choice as being one that demands more than logical decision making. As a game maker, the question that concerns me is: how can we make games where logic and computation cannot be usefully applied, so that the capacity for unconscious decision-making is exercised?

Certainly in Chess you could choose not to go through the computations of "what are my possible moves if I do this and then he does this?" and instead try to make an unconscious decision. But then you're explicitly suppressing reason where it is applicable, and this is a really bad habit to get into. I'd strongly prefer people to do this quite a bit less. If you're in a situation where it's possible for you to work out the right answer, work it out!

Randomness can help a little, but mostly it just means that working out the optimal strategy will involve some probability calculations. You choose the move that has the greatest chance of success. Still, randomness is useful in conjunction with other tools for making decisions interesting, and can greatly increase the variety of situations that you need to think about - Chess openings are well understood, but if the initial position is shuffled this knowledge becomes useless.

Simultaneous or hidden actions can help too. But again they don't cut it on their own - Rock Paper Scissors is the classic example of a game with simultaneous actions and no deep decision-making. RPS - and more generally, many games with simultaneous actions - can be mathematically solved, and the optimal solution is of the form "choose randomly between these moves with these probabilities".

Playing with more than two players can help. But mathematical analysis of games with more than two players can usually reduce the situation to two teams; from a reductionist viewpoint all other players are aligned against the leader. This can lead to terrible games, where being ahead is a disadvantage because it makes you a target, and anyone who approaches winning is consistently attacked and brought back down. But this relies on perfect information; with enough concealment players can be uncertain about who their interests are currently aligned with. Still, this mostly degenerates into the politicking of trying to convince everyone that someone else is in the lead; fun for a while but ultimately fairly limited.
The curious thing about this to me is how much it depends just on the number of players, and not on the specifics of the game system. If there's any way of choosing to target another player, whether explicitly or not, you see the same dynamics playing out again and again. The simple numerics of one-against-many work out much the same in any system. It's possible to get away from it, but takes a legitimate effort.

Adding time pressure helps a lot. David Sirlin talks about this here, under "GDC Microtalks 2012". When you have limited time, you can't do the computations, you have to rely on your unconscious ability to make complex decisions. This applies best to real-time games, but in turn-based games too you can place a time-limit on turns. Chess is way better with a hard time-limit on turns than a soft limit of "should I work things out one step further ahead, or will that just be really annoying for my opponent?"
Real-time games have a different slant on simultaneous actions and hidden information: even if all information is visible, you can't take it all in at once. You have to choose where to look and how quickly to act on what you see; to find the middle ground between reacting prematurely and hesitating too long. In the words of Frank Lantz, "Seeing is statistical".

Wednesday 25 April 2012

mutual learning - an aesthetic for competitive play

Post brought on by a tweet from Frank Lantz and an interview with Tale of Tales.

David Sirlin's excellent Playing to Win series presents an aesthetic for competitive play. An inadequate summary: It is beautiful to continuously improve yourself by trying your best to win games. Any tactic permitted by the rules is valid; do whatever it takes to win regardless of whether it is seen as "not fun" or "exploitative". Games are best played with the strongest opponents you can find, to maximise what you can learn from them and provide the greatest challenge to overcome.

This is not the only viable aesthetic for competitive play. In particular, it doesn't really capture what I get out of competitive games.

From the Tale of Tales interview:
MichaĆ«l: I mean, some people play competitively of course but those are nasty people – you don’t want to play with them! You want to play with nice people who don’t particularly care whether they win or lose but they –
Aureia: They just want to be with you.

I'm ripping this out of context, and I'm sure it was said in a joking manner, but there's a valid point here. Someone who's "playing to win" can be fairly unpleasant to play against.
Example: Someone's playing a game for the first time. They start making moves that make it clear that they've misunderstood or missed some aspect of the rules (legal moves, but very poor ones). Do you a) remind them of the rule, b) wait until it's too late and let them fail. I've played with people who choose b, and not only is it kind of dickish, it's a poor way to teach - failures are best found and corrected as soon as possible.
Example: You don't know a game very well. A more experienced player offers advice. As you play, it turns out their advice just so happened to advantage them and disadvantage another player. (You know who you are.)
So I sympathise with Tale of Tales here; strictly playing to win no matter what isn't very sociable. But the problem there is bad sportsmanship, not the desire to win in itself. I disagree with the sentiment that you shouldn't care about whether you win or lose. Aiming to win is part of what drives games, makes them work at all. If you don't care about winning, there's no particular reason to choose any move over any other - or even to play it all. The magic doesn't happen. I've played Poker for money and not for money; every time it's been for money it's been a lovely sociable game and every time it hasn't it's just been kind of dull. The game is powered by the desire to win; when you take that away it doesn't work the same.

Lantz's comment brings to mind my experience with multiplayer RTS. My impression is that most people do not play against other people until they feel they've adequately learnt a game by playing the singleplayer mode. They are intimidated by the competition. Many players shun competitive online play completely; preferring to stick with single-player or cooperative modes (e.g. "comp-stomp"; a team of human players against a team of AI players). Or when they do play competitively, they impose extra rules like "no rush" - see Rush, Boom, Turtle: "I'm the bad guy?" by Tom Chick; I've been there.
From the POV of the "playing to win" aesthetic this is wrong: playing against AI trains bad habits which must then be unlearned, it is better to continually try yourself against the best available opponents.

So here's my aesthetic:
Competitive games are best played first with an opponent who's also never played before. Together you experience the joy of shared discovery. This is almost cooperative, despite the game being competitive; you are figuring out rules and strategies at the same time, and you communicate your discoveries with each other. Maybe you talk about them together, or maybe you use them to defeat your opponent - either of these is a form of communication. You see each other fail and perhaps you gently mock each other, but you are unashamed because it's only a game and you are in it together.

Board games naturally work a bit like this, because they're typically played in local groups who have similar amounts of experience with a game, whereas online games are played against the keenest players from around the world. If playing online is off-putting because you don't like being beaten over and over again, this is a good approach to follow; it means you're always playing against someone at the same level as you. Bring back the LAN party!

The best game for this for me has been Race for the Galaxy. I bought it having heard that it was excellent but knowing nothing more than that, and my wife and I proceeded to play it almost every day for several months. It has a lot of different stages of understanding; where I've found something that wins pretty reliably so I keep on doing it until either she figures out something that beats it (and then I have to figure out what beats that) or she starts doing the exact same thing and beating me and I have to work out how to do it better. And then, once you've played a hundred or so times and you think you've absorbed the full range of strategies available, you can add in the next expansion and shake things up completely. The designer has talked about how he playtested a lot and carefully balanced the different strategies so that the things that are harder to figure out turn out to be just a bit stronger so that it's worth figuring them out; there's this carefully planned arc of understanding that you go through as you learn the game.

I think Glitch Tank is a good game for this too. It doesn't have as much of an arc as Race does, but it has a delightful sense of bafflement when you first play that is best shared with another.

Tuesday 24 April 2012


This is a Dutch folk game I learnt from my friend Tomf. I really like it. Couldn't find a writeup of the rules online that didn't suck so here is mine:


Take an ordinary deck of playing cards, and a pile of counters to record points.
Remove all the 2,3,4,5,6 cards.
The order of cards is unusual: numbers are higher than face cards, so the order is (lowest to highest) J,Q,K,A,7,8,9,10.
The object of this game is to be the last player remaining. A player is eliminated when they get 15 points.

Each round:
The dealer deals each player a hand of four cards. There will be four tricks, where each player plays one card.
Player to the left of dealer goes first. You can start with any card, but then other players must follow suit if able. The highest card in suit wins, and that player starts the next trick.
The goal each round is to win the last trick; the player who achieves this gets no points and each other player gets 1 point.

The dealer then passes to the left for the next round.

If that's all there was to the game it would be a very boring simple game! But there are two rules that make it interesting:

- At any point, whether it's your turn or not, you may knock on the table. The game immediately pauses, and each player in turn (starting from the left of the player who knocked) chooses to stay in the round or to fold. For players staying in, the number of points at stake goes up by 1; players who fold get the previous number of points.
You may knock more than once in the same round, but not if you were the player who knocked most recently in that round.

- If your hand consists of all face cards, you may mulligan it. Once the cards have been dealt, but before the first player has played a card*, place your hand face down in front of you and draw four new cards.
You might notice that I said face down. This means that it's possible to cheat, and mulligan a hand with number cards in! If another player suspects you of cheating, they can challenge you by turning the mulliganed hand face-up. If they correctly catch a cheat, the cheater gets a point. But if someone challenges incorrectly, they get a point themselves.

* Yes, this does imply that the first player can prevent others from mulliganing by playing very quickly.

Example of play:
four players in order: Stephen, Terry, Sophie, Michael.
* Stephen deals.
* Michael doesn't like his hand, so he places it face down and draws four more cards.
* Sophie suspects Michael of cheating, so she turns over his old hand: J,J,Q,7 - terrible, but there's a number card in it, so Michael gets one point. He still gets to keep his new hand though!
* Terry then knocks, because he thinks his hand is pretty great.
* Sophie folds, taking one point.
* Michael stays in.
* Stephen folds, taking one point.
* Terry plays 8 of Hearts. Michael has to play a Heart if he has one - he plays King of Hearts. Terry wins the trick.
* Terry plays 9 of Hearts. Michael plays 10 of Hearts, winning the trick.
* Michael then knocks, because he's confident now that he has the advantage.
* Terry stays in. The round is now worth 3 points!
* Michael plays 8 of Diamonds. Terry has no Diamonds, so he plays Queen of Clubs. Michael wins the trick.
* Michael plays 9 of Clubs. Terry plays 10 of Clubs, the only card in the game that could have won. Terry wins the last trick; Michael gets 3 points.
* Next round, Terry will deal.

Friday 20 April 2012

Kompendium - IGF feedback

I submitted a collection of 2-player games I was working on to the IGF. Maybe a little cheeky sneaking in ten games for the price of one, but I couldn't pick one and I was working on them all in parallel at the time, considering it as an album.

Since then I got an iPad and started porting them to it, because it seemed a more natural setting for same-computer-multiplayer. Glitch Tank came out of this; it instantly became a much better game as soon as it had touch controls so I polished it up on its own and released it. The rest will be released in some form at some point (maybe individually, maybe as an album, I'm not sure right now), there's some nice stuff there, but I need to spend quite a bit more time on them to get touch controls feeling vaguely acceptable, and I've been distracted making other things.

Here's the IGF judge feedback:

I just lurves me some games-about-gameplay. And this one had lots of really interesting things bouncing off of other things. That said, the heat of frantic two-players-one-keyboard combat is not the most comfortable environment for navel-gazing. Sometimes you just want a second to process, you know? (Maybe less if you are a twitchier or schmuppier player than I'll ever manage to be.)

On the other hand the 2 people playing had some wacky real time exchanges about what they thought was going on. Now that it's over (whew!) I wish I could remember more of what we said...

This game has a lot going for it. I totally dig the art style, especially on Zeta Forge and Hostile Pantograph. These two also had the gameplay that resonated with me the most. I think you could make a little pocket money with these if you could find a good place to release them. Hostile Pantograph could benefit from some AI, so you could play against the computer, but Zeta Forge makes more sense as a multiplayer game. Both of them would be really fun on the iPad, with two players sitting down touching the screen. I really like Shot Shot Shoot and MultiPong, and your games could deliver a similar experience.

Thursday 12 April 2012


Remember my seven-day roguelike?
I've continued to work on it and now here's a more substantial release.
Also ported it to istuff.

ios appstore
windows download
mac download

What's new?
- an ending!
- five different tilesets.
- music.
- 2 new item types.
- 1 new enemy type.
- improved graphics on explosions etc.
- various tweaks and balances.

Ortoslon has done a video playthrough. Somewhat spoilery though! Maybe you should just watch the start?

edit (2012/05/01): updated version. most changes are to the ios version (swipe controls, portrait mode) but there's some minor stuff for everyone.