Game rules in chess

Board and initial position

The board 8х8 grid is used for the game.

The game is on the square-checkered board or fields. Fields are numbered on the rank with Latin letters from «a» to «h» from left to right and on the file are numbered in digits from 1 to 8 from below upwards. Each square has a respective designation, for example c4. Fields are painted in dark and light colours (and are named black and white accordingly) in such a way that the adjacent fields on the rank and file are painted in different colours and the field a8 is a white one.

Two players play in the game. Everyone has a set of pieces which consists of the following: a king; a queen; 2 bishops; 2 knights; 2 rooks; 8 pawns.

One player plays white pieces and another one plays black pieces.

Pieces are located on the fixed positions in the beginning of the game occupying exactly two rows (1 and 2 white, 7 and 8 black). The order of initial location of pieces on the rows 1 and 8 (from a to h): a rook, a knight, a bishop, a queen, a king, a bishop, a knight, a rook. Rows 2 and 7 are occupied by pawns.

Game course

Players make moves one by one. White pieces are the first to make a move.

It is possible to move only one piece during one move. Only the knight can jump over own or the opponent’s pieces; the knight can do this.

It is impossible to make a move on the field occupied by the own piece. At a move on the field occupied by the opponent’s piece the latter is removed from the board (capture).

Moves

Pieces move in the following way:

• The Queen — on any distance vertically, horizontally or diagonally;
• The Rook — on any distance vertically or horizontally;
• The Bishop — on any distance diagonally;
• The Knight — 1 square horizontally and 2 squares vertically or on the contrary, on 1 square vertically and 2 squares horizontally;
• The Pawn — moves with the capturing and without capturing differently:
  • Without capturing - the first move is on 1 or 2 squares forward (for white pieces to move forward means to move in a direction of row number increase, for black pieces – row number decrease), and the subsequent moves — only on 1 square forward;
  • With capturing — on one square forward and diagonally to the left or to the right;
  • If a pawn reaches the opposite side of the board (white — the 8th row, black — the 1st row) then the one whose moves must substitute it on any other piece of the same colour (if desired) except the king (promotion);
• The King — on one square in any side.

Besides there are two special moves:

• Castling - if the king and one of the rooks of the same colour did not move from the game beginning then the king and this rook can change their position simultaneously (It is a move of the king. So the king needs to be the first to be moved on a board): the king moves on 2 squares in a direction to the rook and the rook is put in the field between the initial and final position of the king.
  
  Castling is temporarily impossible if:

  • The field where is the king is under attack by one of the opponent’s pieces;
  • The field which the king needs to pass is attacked by one of the opponent’s pieces;
  • The field which the king must occupy is attacked by one of the opponent’s pieces;
  • There is a piece between the king and a castle which was supposed to be used for the castling. Due to this piece it’s impossible to make a castling.
  
  Castling is impossible if the king or an appropriate rook already made a move.
• The capturing in passing - if a pawn makes its first move on two squares through the field which is under attack of the opponent’s pawn then this pawn can be captured during the following opponent’s move. The attacking pawn in this capturing moves on the field where the moved pawn was located before (that is as if that pawn had moved not on two but only on one square). The capturing in passing is only possible in reply on the «long» move of the pawn. It’s not permitted to do the same when making the following moves.

Limitations on possible moves:

• A field is considered to be under the opponent’s attack or already beaten if the opponent during his move could capture a piece which was there (irrespective of the fact whether there is such a piece on this field).
• The King which is on the attacking square is called to be standing in check.
• It is forbidden to make a move if the king after the move is under check. If the king is already under check then any moves are forbidden except the ones after which the King will not be under check.
  
  There are three ways to avoid the check: to capture a piece which attacks the King (it is impossible if two pieces make the check simultaneously), to use another piece to avoid the check (it is impossible if the knight checks or two pieces make the check simultaneously), to move away from the square which is under attack.


• If the King is under check and the player doesn’t have any moves allowing to avoid this check then such a situation is called a checkmate.
• If the king is not under check but it is impossible to make any moves then such a situation is called a stalemate.

The game result

The game can finish with a winning of one of the opponents or to be a draw.

The winning is fixed in the following cases:

• Checkmate is declared on the board. The player declared the checkmate to the opponent’s King wins.
• One of players resigned. The player who considered that the further fighting is senseless can resign at any moment. His opponent is declared to be a winner.
• One of players exceeded the time control. His opponent is declared to be a winner if he formally has enough material (pieces) to checkmate (see below «Time control»).

The draw is declared in the following cases

• The stalemate.
• Players agreed on a draw. It means that one of the players during his move offered a draw and the other accepted it. It is enough to say «draw» when offering a «draw». If the opponent makes a move without giving a positive answer on the proposition then the offer is considered to be rejected.
• Both opponents don’t have enough quantity of pieces necessary for the checkmate (for example, there are only Kings and one «easy» piece on the board left).
• One of players exceeded the time control but his opponent doesn’t have enough material (pieces) to checkmate.
• Triple duplication of the same position (not necessarily during three moves in a row). Moreover the notion of the position includes the location of pieces, the move sequence and possible moves (including the right on the castling and the capturing in passing for both sides).
• Both players made 50 last moves without capturing and move of a pawn. As well as in the previous case the draw is declared on the request of any players.

Time control

Time control is always used for chess games. A chess clock is used for this purpose (on game servers - the timer).

A player who delayed time is considered a defeated except in cases when his opponent doesn’t have enough material (pieces) to checkmate.

Points counting

Depending on the game result a player gains the following quantity of points: