Apocalypse (chess variant)



Apocalypse is a chess variant invented by C. S. Elliott in 1976. Each player starts with two horsemen and five footmen on a 5×5 board. The two sides make their moves simultaneously.

The game was featured in Issue 53 of Games & Puzzles magazine. The name Apocalypse is a reference to the Four Horsemen of the Apocalypse.

Game rules
The starting setup is as shown. Horsemen and footmen move the same as knights and pawns respectively do in chess, except footmen do not have a double-step option on their first move. For each turn, each player secretly writes down their move, then the players simultaneously declare them. The following rules apply:
 * If each player moves a piece to the same square, a horseman captures a footman. Same-type pieces are removed from the board.
 * If a capture is declared using a footman, but the piece to be captured moves from its square, the footman move still stands. The move converts to being a diagonal step instead of a capture.
 * If a declared move is illegal, the player loses their turn and incurs a penalty point.

Upon reaching the farthest, a footman is promoted to a horseman when the player has fewer than two horsemen. Otherwise, the player must redeploy the footman to any vacant square not on the farthest rank; the square to which the footman is redeployed must be written as part of that footman's move. It is illegal for a player to advance their only footman to the last rank while having fewer than two horsemen.

End of game
A player wins by having at least one footman while their opponent does not. Accumulating two penalty points forfeits the game. The game is drawn if each player loses their last footman at the same time. If both players have footmen remaining but at least one of the players has no legal moves, the game is a draw (this is similar to the stalemate rule).