Rules for Tri-D Chess:

[RULES]:

[STARTING POSITIONS]:

Are shown in the diagram below: the following diagram has been flattened for reading convenience

The first starting position is chosen if the coin lands on heads.

This starting positing is called “Alpha” because it is the first one.

Alpha

The second starting position is chosen if the coin lands on tails.

This starting position is called “Beta” because it is the second one.

Beta

They have a preference in starting position Beta. Everything from A to D is the Queen’s side and everything from E to H is the King’s side.

[MOVEMENT OF ATTACK BOARDS]:

Attack Boards can be moved from their starting position to an unoccupied peg only when they are empty or carrying only one Pawn, above or below the chosen fixed level. Pegs are located on the outer corners of the fixed levels.

[MOVEMENTS OF PIECES]:

THE PAWN: the Pawn may move 2D as in traditional chess. In changing levels a pawn may move straight up or down one level, or may slope up or down one level (but only moving ahead toward the opposing rank). In its initial move a given Pawn may choose to move forward two spaces, or slope forward two spaces. A Pawn may capture only by making a diagonal capture-move. This works 2D just as in traditional chess. A pawn may also capture by moving one space triagonally. An ‘en passant’ capture is made when a Pawn captures the opposing Pawn on its left or right side by moving diagonally or triagonally. A Pawn can be moved with an attack board, this is the only piece that can do this, but when this is done the Pawn can no longer be captured ‘en passant’. The Pawns at A2, B2, G2, H2, A17, B17, G17, and H17 may make their first move by moving one or two spaces to the right or left so as to allow them to leave their start positions on the Attack boards.

THE ROOK: the Rook may move straight up or down or may slope along the same rank or file.

THE KNIGHT: the Knight may change levels by moving one space up and two over, or by moving two spaces up and one space over. Only the Knight may move over pieces or through spaces that do not exist.

THE BISHOP: the Bishop may move diagonally on the same level or may change levels by moving triagonally.

THE QUEEN: The Queen may move either as a Rook would move or as a Bishop would move.

THE KING: The King may move just as the Queen but may only move one space at a time. “Castling” on the King’s side just the position of the King and the Rook are changed, for example the King moves from G18 to H18 and the Rook exchanges its spot to where the king was. “Castling” on the Queen’s side the King moves from G18 to B18 and the Rook exchanges its spot to where the king was.

DEFINITIONS:

SLOPING MOVE: A sloping move is a diagonal move which changes levels within a single file or rank but which slopes diagonally at the same time.

TRIAGONAL MOVE: A triagonal move is a move which changes levels diagonally passing through more than one rank and/or file.