If a player wants to adjust a piece on its square without being required to move it, he can announce j’adoube ("I adjust") before touching the piece (Hooper & Whyld 1992:425). A player may not touch the pieces on the board while it is his opponent's turn.
There is a separate rule that a player who lets go of a piece after making a legal move cannot retract the move.
If a player having the move deliberately touches one of their pieces, he must move it if it can be legally moved. So long as the hand has not left the piece on a new square, the latter can be placed on any accessible square. Accidentally touching a piece, e.g. brushing against it while reaching for another piece, does not count as a deliberate touch.
If a player touches a hostile piece, then he must capture it if the piece can be captured. If a player touches one of his pieces and an opponent's piece, he must make that capture if it is a legal move. Otherwise, he is required to move or capture the first of the pieces that they touched. If it cannot be determined whether he touched his own piece or the opponent's piece first, it is assumed that he touched his own piece first. If a player touches more than one piece, he must move or capture the first piece that can be legally moved or captured. An exception to that is an attempted illegal castling; in that case the king must be moved if possible, but otherwise there is no requirement to move the rook.
When castling, the king must be the first piece touched. If the player touches his rook at the same time as touching the king, he must castle with that rook if it is legal to do so. If the player completes a two-square king move without touching a rook, the player must move the correct rook accordingly if castling on that side is legal. Otherwise, the move must be withdrawn and another king move made.
When a pawn is moved to its eighth , once the player takes his hand off the pawn, a different move of the pawn can no longer be substituted. However, the move is not complete until the promoted piece is released on that square (Just & Burg 2003:20–23).