Правила классических шахмат

Castling

Castling consists of moving the king two squares towards a rook, then placing the rook on the other side of the king, adjacent to it. Castling is only permissible if all of the following conditions hold:

1. The king and rook involved in castling must not have previously moved;
2. There must be no pieces between the king and the rook;
3. The king may not currently be in check, nor may the king pass through or end up in a square that is under attack by an enemy piece (though the rook is permitted to be under attack and to pass over an attacked square);
4. The king and the rook must be on the same rank