Object:

To win at Chess, you must trap your opponent's king so that he is threatened, and has no legal moves that would make the king safe. This is called a "checkmate".

How to play

Pieces are arranged on the board automatically by the computer. If you decide to play on a chessboard, note that the Queen always takes her own color when arranging the back row. Also, the lighter squares should be in the lower right corner of the board. (if not, just rotate the board!)

White always goes first, followed by black. Each player takes turns moving one piece.

Each piece has its own legal ways of movement. Moves can end either on a vacant space, or on a space occupied by an opponent's piece. Ending a legal move on a square occupied by an opponent's piece is called a "capture", because the opponent's piece must be removed from the board.

No piece may move over or through any other pieces, with the exception of the Knight.

Legal Moves

Pawn - A pawn may move one square at a time, with the exception of its first move, which may be two squares, though this leaves the pawn vulnerable to "en passant" capture for a single move only (see "special rules" below). Pawns may only move directly forward, with the exception of a move to capture, which must be a forward diagonal move of one square.

Rook - Shaped like a castle, the rook is one of the most powerful pieces in Chess. It can move in a straight line in any column or row. Rooks can not move diagonally.

A Rook can also be moved on the same turn as a king, but only if the king is Castling (see "special rules" below).

Knight - Shaped like a horse, the Knight is the only piece on the board that may jump over other pieces (Or arguably, since it does not move in a straight line, it never actually meets the pieces it jumps over). Knights can move two squares in one direction, followed by one square in a perpendicular direction in a single move. A good way to visualize the sphere of the knight's movements is to consider the squares of the opposite color that aren't next to the night, but aren't more than 2 squares from the knight to be legal moves. (of course, the computer will make sure you make legal moves).

Bishop - Starting next to the knight, the bishop is like a rook, but it can only move diagonally, instead of horizontally and vertically.

Queen - Each side has only one Queen; it's the most powerful piece on the board, because it can move horizontally, vertically, or diagonally.

King - Each side has only one King; it's important to keep it safe, because his entrapment ends the game. Kings can move one square in any direction (unless they are castling; see "special rules" below.) A king may not move onto any square where he may be threatened by an opposing piece.

Special Rules

Check - when a King is threatened by an opposing piece, he is "in check". The opponent's next maneuver must cause the king to no longer be threatened, by either moving the King out of harm's way, or by moving another piece to eliminate the threat to the King.

Checkmate - When a King in check can not do anything to remove the threat, the game is over. The winner is the player who trapped the opponent's king.

Stalemate - If the King is not in check, but a player's only legal move is to move the King into check, the game is a tie.

Also, if there are not enough pieces on the board to allow a checkmate to ever occur, the game is also a stalemate.

Castling - The King may move two squares to the side, and the rook from that side may move to the square that the king moved through. But in order for this to happen, there may be no pieces obstructing either the king or the rook, and the King may not be in check, or travel through or into check, when castling.

Promotion - a pawn that reaches the last row on the other side of the board may be promoted to a knight, bishop, rook, or queen.

en passant capture - probably one of the most obscure things you'll never have to learn about Chess. When a pawn moves two squares forward, any piece may capture the pawn in passing, "en passant" by landing on the space immediately behind the pawn (or, as if the pawn had only moved one square).