p.boxed
	| In addition to standard moves, a piece can be exchanged
	| with an adjacent friendly unit.

h3 Specifications

ul
	li Chessboard: standard.
	li Material: standard.
	li Non-capturing moves: standard + switch.
	li Special moves: standard.
	li Captures: standard.
	li End of game: standard.

h3 Basics

p.
	Instead of a normal move, a piece may be exchanged with an adjacent friendly one.
	Switching can move pawns until rank 1 or final rank. In the first case a 2-squares
	jump is possible, and in the second a promotion occurs.
	Switching must involves two different units.
	Switching while the king is under check is not allowed.

p.
	Notation: a switch move is marked by the capital letter 'S' followed by
	the exchanged squares. Example in diagram: Sb8c8

figure.diagram-container
	.diagram
		| fen:1RB3k1/5ppp/8/8/8/8/8/K7:
	figcaption White can mate in 1 by switching b8-c8

p.
	Note: if the king and rook are on two adjacent squares, castling and switching
	from the king are triggered in the same way. Castling takes priority:
	if you wanna switch, use the rook.

h3 Source

p
	a(href="https://www.chessvariants.com/diffmove.dir/switching.html") Switching chess 
	| on chessvariants.com.