Chess rules
Rook
The Rook is the second most powerful piece in the game. It can move an arbitrary number of squares in horizontal or vertical direction. The possible sqares for a rook can be remembered based on the fact that they appear as a plus sign (+):
Bishop
The Bishop can move to all squares the are located diagonally from its current position. Hence the squares it can access appear as an "x". The bishop is slightly less powerful than the rook, as it can only reach those squares having the same color as its starting square.
Queen
The combines the movement of the rook and bishop, as it con move horizontally, vertivally, as well as diagonally. Therefore, it is considered to be by far the most powerful piece. The Queen plays a key role when attacking the opponent's position, esppecially the King. Hovever, it should not be used too often in the opening.
Knight
The moving path of the Knight has the shape of an "L" letter. It goes two squares in horizontal or vertical direction and then one square perpendicular to that direction. The Knight is approximately as powerful as a Bishop. It is the only piece that can jump over other pieces, making it better in closed position.
Pawn
The pawn is the least powerful piece. Hovever, it has the most complex movement rules. If a pawn moves for the first time, it can go one or two squares towards the enemy position. Once it has moved, it can only one square forward for the rest of the game. Moreover, the pawn captures other pieces by moving diagonally one square towards the opponent, which is different from its regular movement. Pushing a pawn to the opponent's backrank allows the player to convert it into an arbitrary piece, except a king.
The following table shows the approximate value of each piece. However, the strength of a piece also depends on the concrete position. For example, Knights are better in closed positions, whereas bishops stronger in open positions.
King
The King is the most important Piece in the game. When the King gets checkmated, the Game is over. Therefore it is imortant to keep it in a safe position throughout the game. The game ends if the king gets checkmated or stalemated. The movement of the King is quite straightforward, as it can only move to all of its adjacent squares.
| Pawn | Knight | Bishop | Rook | Queen |
| 1 | 3 | 3 | 5 | 9 |
Checkmate
To win the game, a player has to checkmate the king of the opponent. That happens when the king of the opponent is under attack, i.e. checked, while the opponent has no legal moves to step out of that check. The following image shows a position where the black King is checkmated. It is attacked by the first rook, whereas the second rook prevents it from escaping to the second rank.
