Chess rules

Start

Chess is played on a board consisting of 8x8 alternating dark and light squares. Both players start with 16 pieces in their own color. The goal of Chess is to ensure that the opponent's king is unable to make a move without being captured (checkmate).

Course

Taking turns, the players move one of their pieces, each of which has its own way of moving. Adjacent to the current square, these are:
• Pawn: 1 square vertically forward or 1 square diagonally forward if a piece is captured
• Rook: along the entire horizontal or vertical lines
• Bishop: along the entire diagonal lines
• Kinght: 2 squares horizontally and 1 square vertically or 2 squares vertically and 1 square horizontally
• Queen: along the entire horizontal, vertical or diagonal lines
• King: 1 square horizontally, vertically or diagonally

The following rules apply:
• When a piece ends on a square that has an opponent's piece on it, the opponent's piece is removed from the game (captured).
• With the exception of the knight, a piece may not jump over other pieces.
• The king may not be moved to a square on which he could then be captured (check). If this is no longer possible and the king is not in check, the game ends in a draw (stalemate).
• If a king is in check, it must first be moved.
• If a pawn has never been moved, it may also be moved 2 squares vertically forward.
• If a pawn has reached the other side, it is upgraded to a rook, bishop, knight or queen. The piece is chosen by the current player.
• If the same position occurs 3 times, the game ends in a draw (threefold repetition).

Chess also has 2 special rules:

En passant
If a pawn is moved 2 squares forward and it ends up to the left or right of an opponent's pawn, then the opponent may capture this pawn in his next turn using a diagonal move forward with his respective pawn, ending on the square behind the captured pawn. This capture move is only possible once directly after a player has moved a pawn 2 squares forward.

Castling
If both king and a rook have never been moved and there are no other pieces between them, the king may move 2 squares towards the rook. The rook then jumps to the next square over the king. This move is only possible once.

End

The game ends when a player is unable make a move without having his king captured. The other player wins the game.