Check out Cylindrical Chess, our featured variant for March, 2023.

This page is written by the game's inventor, Kevin Pacey. This game is a favorite of its inventor.

4*Chess (four dimensional chess)

```Here's a 4 dimensional chess game that can be played as if on a 2D plane. The game is played using sixteen 4x4 (2D) mini-boards that are arranged in four columns and four rows. A 16x16 board with appropriate spacing could be used even on a coffee table; it would be about the size of a Scrabble board (15x15 for that). Using a computer program for it, a player could check if he is making a legal move, and whether it is mate or stalemate, for example. It's based on a BASIC computer program I made for it in the 1980's, which took up less than 16K. I played a game of it with a friend, and it didn't take too long after a blunder, as we knew a 4*Chess King and 4*Chess Queen vs. 4*Chess King can win very quickly.

Note that some links are provided in the Notes section, for further reference. A Game Courier preset for play is available.```

Pieces

In 4*Chess, some 3 and 4 dimensional moving pieces are introduced, and all the pieces may possibly move between the mini-boards when performing a move (note that 'coordinate' in these instructions refers to the rank or file of a square on a mini-board, or refers to the row or column number of a mini-board): D=4*Chess Balloon (I'd nickname it Dirigible) - moves like a bishop except changes 4 coordinates as it moves & stays on same square colour (standard 4D fairy chess piece); U=4*Chess Unicorn - moves like a bishop except changes 3 coordinates as it moves (standard 3D fairy chess piece); B=4*Chess Bishop - changes 2 coordinates as it moves, like a bishop (does not change square colour even if moving to another mini-board); R=4*Chess Rook - changes 1 coordinate as it moves, like a rook; Q=4*Chess Queen - moves like a 4*Chess Bishop or 4*Chess Rook, or a 4*Chess Unicorn, or a 4*Chess Balloon; K=4*Chess King - moves like a 4*Chess Queen, only one square/mini-board at a time (no castling); N=4*Chess Knight (nicknamed Horse) - changes 1 coordinate by 1 square and 1 coordinate by 2 squares, like a knight; P=4*Chess Pawn - moves like a 4*Chess Rook (unless capturing) except only moves forward one square at a time on a rank, or forward by one column or one row to another mini-board (but moves to same rank & file there). If it is making a capture it moves like a 4*Chess Bishop, except only moves by one square, or by one mini-board that's adjacent diagonally or by one row or by one column, and never retreats by rank or mini-board (i.e. by row or column). 4*Chess Pawn promotions occur on the last rank of the corner mini-board where the enemy 4*Chess King starts the game, and a 4*Chess Pawn may promote to any 4*Chess piece type (other than 4*Chess King). There is no double step or en passant, and it is possible for a 4*Chess Pawn to early on avoid being captured by an enemy 4*Chess Pawn simply by moving to the last rank of a mini-board (except for the appropriate promotion mini-board). Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess Unicorn {(U)} involved: Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess Bishop {[B]} involved: Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess Knight {(N)} involved: Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess Rook {(R)} involved: Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess Balloon {(D)} involved: Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess Queen {(Q)} involved: Here's a diagram illustrating all possible legal moves on an empty board by the White 4*Chess King {(K)} involved: Here's a diagram illustrating all possible legal moves by the 2 White 4*Chess Pawns {(P)} involved: The White 4*Chess P at ab43 in making non-capturing moves can advance like a 4*Chess Rook, but only forward, by a single step, towards the last rank of White's promotion mini-board in the upper right corner. That is, to either nearby marked square if it is unoccupied. In making capturing moves it moves like a 4*Chess Bishop, but only forward, by a single step, towards the last rank of the promotion mini-board. That is, to any square occupied by a Black 4*Chess Unicorn in the diagram {[U]}, taking it. Note that none of this White 4*Chess Pawn's possible moves result in it promoting since it will not have reached a square on the last rank of White's promotion mini-board (i.e. any of the squares da44, db44, dc44 or dd44). Similarly, the White 4*Chess P at db13 in making non-capturing moves can advance like a 4*Chess Rook, but only forward, by a single step, towards the last rank of White's promotion mini-board in the upper right corner. That is, to either nearby marked square if it is unoccupied. In making capturing moves it moves like a 4*Chess Bishop, but only forward, by a single step, towards the last rank of the promotion mini-board. That is, to any square occupied by a Black 4*Chess Rook in the diagram {[R]}, taking it. Once again note that none of this White 4*Chess Pawn's possible moves result in it promoting. Here's a diagram illustrating all possible legal moves by the 2 White 4*Chess Pawns {(P)} involved: The White 4*Chess Pawn at square cb34 has earlier reached the last rank of a mini-board. In making non-capturing moves it can move to either nearby marked square if it is unoccupied. In making capturing moves it can take any Black 4*Chess Knight in the diagram {[N]}. It can also take the Black 4*Chess Queen in the diagram {[Q]}, in which case it is promoted to something since it has reached a square on the last rank of White's promotion mini-board. The White 4*Chess Pawn at square bb12 in making non-capturing moves can advance like a 4*Chess Rook, but only forward, by a single step, towards the last rank of White's promotion mini-board in the upper right corner. That is, to any of the 3 nearby marked squares if it is unoccupied. In making capturing moves it moves like a 4*Chess Bishop, but only forward, by a single step, towards the the last rank of the promotion mini-board. That is, to any square occupied by a Black 4*Chess Balloon (aka Dirigible) in the diagram {[D]}, taking it.

Rules

`Stalemate is a draw, as in standard chess.`