I’ve never actually managed to play a game of Ultima all the way through. I have a couple of computer programs that will play it, but I usually bail after only a few moves, because Ultima it pretty confusing. It was invented in 1962 by a fellow named Robert Abbott. It uses a conventional chess board and pieces (although one rook has to be stood on its head). None of the pieces except the king behaves in anything like the expected manner. Even the names have been changed.
Except for the king and the pawns, all of the pieces in Ultima move like a chess queen. The pawns move like rooks. But only the king captures like a chess piece. In place of the queen, you have a withdrawer, which captures by moving away from an adjacent piece. Instead of bishops, you have chameleons, which capture (very confusing, this) in the manner of whatever piece they’re capturing. The knights are transformed into long leapers, which capture pieces by jumping over them. One rook is a coordinator, which captures pieces based on the relative positions of it and its king. The other rook is an immobilizer, which doesn’t capture at all — it freezes enemy pieces. The pawns are still called pawns, but they capture by clamping an enemy piece between two friendly pieces.
That, in a nutshell, is why I’ve tiptoed away from Ultima. But a lot of people do play it.
Not surprisingly, several people have proposed variants of Ultima.
In Rococo, one of the chameleons is replaced with an advancer, the coordinator is ditched in favor of a swapper, and the pawns are entirely different. Also, Rococo is played on a 10×10 board, but pieces can only end up on the edge squares when they’re making a capturing move. If you’re thinking of chess captures, this makes no sense, but it does make sense in Rococo.
Maxima uses the Ultima pawns, but there are only six of them per side, the other two having been replaced with guards. A couple of mages are added to the Ultima piece set. Guards and mages capture enemy pieces the way standard chess pieces do, by moving onto their square. This strikes me as weakening the Ultima concept, which I would describe as “everything is different!”
Fugue uses the Rococo pawns, but the chameleons and coordinator are gone. Instead, you get a swapper, an archer, a pushme-pullyu, and a chess queen.
Yesterday I ran into a newer game called Arimaa. Like Ultima, Arimaa can be played using a standard chess board and pieces, yet it bears almost no resemblance to chess. The only resemblance, in fact, is that your goal is to get one of the pawns across the board to a square on the far side. If you can do that, you win. One of the inspirations for Arimaa was the fact that a good computer program can beat a human player at chess. Computers do this by searching through and evaluating all of the possible moves. The number of possible moves in a given position in Arimaa is several orders of magnitude larger than in chess, making this kind of automated game-play completely impractical with present-day computers.
An exhaustive search of possible moves is also impractical with go. A number of computer programs play go, and a couple of them are pretty good, but none is as good as a skilled human player. Computers play go by attempting to analyze the board positions the way a human would … sometimes very well, sometimes in shockingly inept ways. A single turn in Arimaa can include up to four piece moves, so the total number of possible moves in a single turn is much larger even than in go.
I’m hoping to have a chance to play Arimaa, but first I’m going to have to find a human opponent. They have some kind of online play (against human opponents), but I’m not quite ready to embarrass myself yet.