#chess variants

Before I explain the piece movements, here's a short glossary of terms that I'll use when describing them.

Step - Movement to an adjacent square. Notated with a dot in the destination square, or an X for capturing-only steps.

Slide - Movement along a straight path of unoccupied squares to reach a square that is not adjacent. Notated with an arrow that follows the path of squares.

Jump - Movement directly to a square that is not adjacent, ignoring any pieces that may be in the way. Notated with an arrow.

(X, Y) jump - When a piece makes an (X, Y) jump, it jumps X squares in one orthogonal direction, then Y squares in a different, perpendicular direction. X and Y can be swapped freely, so an (X, Y) jump is equivalent to a (Y, X) jump.

Orthogonal - Forward, backward or sideways, perpendicular to the edges of the board.

Diagonal - An equal amount of movement along two perpendicular orthogonal directions.

Forward - Towards your opponent's side of the board. (Backward, similarly, is towards your own side of the board.) For White, this would be moving towards the 16th rank of the board, while for Black it would be moving towards the 1st rank.

In any direction - Orthogonally or diagonally.

(Unless otherwise stated, and with the exception of the above definitions, "move" specifically refers to non-capturing moves, while "capture" specifically refers to capturing moves. "Giving check" refers to capturing moves that can only target a King.)

The King

Moves or captures by stepping one square in any direction.

Royal - If your King is threatened with capture, you are in check, and you MUST remove the threat. If you cannot remove the threat, you are checkmated and you lose the game. You may not willingly move into check.

Castling - Castling is done by having the King move two squares towards its Rook, then the Rook jumps to the square the King passed through. The King may not castle into, out of or through check, all squares between the King and Rook must be open, and neither the King nor the Rook used may have been moved this game.

The Queen

Moves or captures by sliding any number of squares in any direction.

The Rook

Moves or captures by sliding any number of squares in an orthogonal direction.

The Bishop

Moves or captures by sliding any number of squares in a diagonal direction.

The Knight

Moves or captures by making a (2, 1) jump.

The Pawn

Moves by stepping one square straight forward. Captures by stepping one square diagonally forward.

Head Start - May slide up to four squares forward if it is on or behind its starting rank. (For white Pawns, this only works if done while on or behind the 4th rank, for black Pawns, only on or behind the 13th rank.)

En Passant - If an opposing Pawn uses its Head Start to move past a square where your Pawn could have captured it, you may move your Pawn into that square, then capture the opposing Pawn anyway.

Promotion - A Pawn that reaches the other side of the board (the 16th rank for white Pawns, or the 1st rank for black Pawns) becomes any piece except for a King, another Pawn, a Drunk Pawn, or a Rookie.

The Archbishop

Has all the movement capability of both the Bishop and the Knight.

The Chancellor

Has all the movement capability of both the Rook and the Knight.

The Cannon

Moves like a Rook, but cannot capture like one. Instead, to capture a piece, there must be a hurdle of either color between the Cannon and its target, which the Cannon jumps over to reach the target. The Cannon may not jump if not capturing, and may only jump over exactly one piece per move.

The Archer

Moves like a Bishop, but cannot capture like one. Instead, to capture a piece, there must be a hurdle of either color between the Archer and its target, which the Archer jumps over to reach the target. The Archer may not jump if not capturing, and may only jump over exactly one piece per move.

The Time Machine

Moves and captures like a Queen, but three turns into the future. To do this, declare a valid square that the Time Machine will land on, then remove it from the board with three time counters. Every turn, after you make your move, remove a time counter from the Time Machine, then if there are no time counters left, return it to the board on the square that was declared three turns ago. Any piece in that square is captured, even if it's a friendly piece. The Time Machine threatens the square it's about to land on, even if there are still some turns left before it will land. Kings who are standing in that square are in check, and if a Sumo Wrestler could push a King onto the square a Time Machine is about to land on on the next turn, that King is in check.

The Champion

Moves and captures by stepping exactly one square orthogonally, or jumping exactly two squares in any direction.

The Wizard

Moves and captures by stepping exactly one square diagonally, or making a (3, 1) jump.

The Kitsune

Moves and captures by making a doubly-bent sliding move; first, the Kitsune steps one square in an orthogonal direction, then turns 45 degrees left or right and slides any number of squares (including 0) in the resulting diagonal direction, then turns 45 degrees left or right again and steps one square in the resulting orthogonal direction. The Kitsune cannot capture until the final orthogonal step.