The King.
The King may move from the square it occupies to any square satisfying the following conditions:
1. A neighbour to the square of occupation.
2. Not occupied by a man of its own party.
3. Not menaced by any hostile piece.
Once during the game the King may violate the first of these rules, namely, in Castling, otherwise never. In Castling, the King is moved TWO squares to the Right or Left, as the case may be, and the Rook towards which the King has moved is then placed upon the square which the King jumped over. But this move is not permitted when
1. The King is in "Check," i.e., menaced with capture.
2. The King or Rook has already made a move.
3. The move of the Rook is obstructed.
4. The King or Rook after Castling would be exposed to capture.
What has been said here in dry words may now be presented pictorially.
The White King placed on c2 has only ONE possible move, to wit, to b2. It may go there, because firstly, that square is neighbour to c2; secondly it is not occupied by a man of its own party but a hostile one; and thirdly, the square b2 is not menaced by any enemy, neither the Black King nor the Black Rook, nor the Black Pawn in their present positions being able to capture a piece on b2. On the other hand, the White King could make no other move; it cannot move to d1, on account of the Black Rook, nor to b3, d3, on account of the Black Pawn, nor to d2 because of the White Pawn standing there, still less to c1, where two slayers would await it, nor to c3, which is menaced by Bishop b2 and obstructed by a White Pawn besides. To other squares it cannot move since they are not neighbours to its present residence.
The reader may demonstrate that in the above position also the Black King has only one possible move, namely, to g7.