In preparing for the next contest (which may be starting in February 2011, so I've heard), we have to settle on a game. The earlier this is done, the better, so we can nail down rules specifics (and map generators, if necessary). There are already some new ideas being discussed and drawn out in the Suggestions forum, and the google repo contains a couple of wiki pages that are good to read: http://code.google.com/p/ai-contest/wiki/GameCriteria and http://code.google.com/p/ai-contest/wiki/GameIdeas. I won't copy them completely here, but I will summarize.
Game Criteria: We want to pick a game that is Easy (to write a bot for), Familiar (people have seen it before), Interesting (fun to think about/read about/watch), Technically Feasible (with our finite time and machine resources), and Non-trivial (there shouldn't be an obvious best strategy). Obviously "Familiar" is the weakest requirement. I would venture a guess that many people didn't know what Galcon was before the Planet Wars contest.
Going through the types of games, I find there are three main choices that differentiate them partway: 1v1 or multiplayer, turn-based or simultaneous turns, and fixed layout (like Chess) or randomized starting positions (such as maps or starting pieces). We have to consider each decision carefully against our game criteria to narrow down what would be an acceptable game to choose. The last two games were Tron and Planet Wars, both 1v1 games with simultaneous turns and randomized maps.
Multiplayer games can be more Interesting and Non-trivial than 1v1 games, but our current rating system (ELO) isn't a good metric for multiplayer game rankings, though some people have tried to do so (eg, considering the game as a set of 1v1 games between each player, so a four-player game is three "games" per player). Second, running more bots for a multiplayer game will reduce the number of games per minute we can support.
Simultaneous turns make the game more interesting due to a "real-time" feel it gives. Alternating turns means one player goes first.
Randomized setups are more interesting due to the randomization factor, but sometimes using two different sets of maps can change the order of player rankings.
The following are my personal opinions and not set in stone.
I would recommend a 1v1 simultaneous turn game with randomized setups. My reasoning is that a multiplayer game will have a higher a barrier to create an AI for, will take longer to set up a contest for, and will require much more resources to have a similar rate of games. The second reason is my primary objection to doing a multiplayer game for the next contest; I am not ruling it out for a future contest where we have more preparation time. The simultaneous turn and randomized setups are mostly cosmetic preferences, for more interesting games.
I want to eliminate Chess and Go for being done to death, Arimaa for already going on elsewhere, Least Unique Positive Integer and Maze Escape for being dull. (Mazes are also a popular AI puzzle.) RPS, Tron, and Galcon have been done before. Eliminating all the other fixed layout and multiplayer games from the Game Ideas list leaves Blokus, Scrabble, Multi-Agent Battle, and Billiards, none of which I am particularly enthused about.
Any ideas or opinions?