The king starts the game on the e1 square.

A chessboard has 64 squares, arranged in an 8x8 grid.

Castling is a special move where a player moves their king two squares to the side and then moves a rook to the square that the king passed over.

Checkmate is the situation where a player's king is under attack and has no legal moves to escape.

Stalemate is the situation where a player's king is not under attack but has no legal moves to make.

Capture is the move where a player takes an opponent's piece off the board by moving their own piece to the square that the opponent's piece occupies.

Pawn promotion is the move where a player moves their pawn two squares forward from its starting position.

En passant is the move where a player captures an opponent's pawn that has just moved two squares forward from its starting position.

The rule that states that a player cannot move their king into a position where it would be under attack is called an illegal move.

The rule that states that a player cannot make a move that would put their own king in check is called an illegal move.

The rule that states that a player cannot move a piece to a square that is already occupied by one of their own pieces is called an illegal move.

The rule that states that a player cannot make a move that would result in their king being in checkmate is called an illegal move.

The rule that states that a player cannot make a move that would result in their king being in stalemate is called an illegal move.

The rule that states that a player cannot make a move that would result in their king being in check is called an illegal move.

The rule that states that a player cannot make a move that would result in their king being in checkmate is called an illegal move.