Another variant of chess is "alice through the looking glass chess" It is played on two boards. A move is made on on board but the piece transports itself to the equvalent place on the second board. Each move results in such a transportation. The King can get out of some tricky situations this way.

There is the famous star-treck chess, rules are available. I have seen rules for chess on an 8X8X8 grid, but never played this. I hvae played on an 8X8X3 grid. The central tier contains the usual pieces, the upper and lower tiers have princes and princesses instead of Kins and Queens. The rooks on these boards can move in 3-d as can the knights and the bishops (they have different names, but I have forgotten them.) The game is won either by mating the King or capturing both princes. After playing a few games of this, regular chess feels limited.

Another variant I have played is a four player game played on the one board. 8X3 grids are added to the four sides of the chess board and four complete stes of different colours are placed there. You can either play in pairs or against each other. The game is fairer when played in pairs as it prevents three ganing up on one.

There are rules available for Klingon chess. The King can be captured, but the player playes on, to the death and for honour. Pawns reaching the eigth rank instead of being promoted get displaced to a random position on the board. If there is already a piece there both are destroyed in the colliison. There are some other modifications in the way pieces can combine when making moves, alltogehter a very chaotic and bloody game.

There are rules for one dimensional chess,

Remember, if you ask someone to play a game of chess it is like telling them that you hate them.