Takebacks

In the toolbar at the top of the Game Window, you will find a Request takeback icon, represented by an arrow pointing left . Clicking this button sends a request to your opponent to take back the previous move. Clicking multiple times will request takebacks of additional moves. If your opponent agrees, the game will revert the specified number of moves.

Some players choose to block takeback requests with the console command set notakeback 1.

IMPORTANT: Nobody, ever, is obligated to grant a takeback. Refusing to give a takeback is NOT unsportsman-like. Takebacks are NOT in the rules of chess. You, and you alone, are responsible for making your moves and avoiding "mouseslips" and "typos". If you ask for a takeback from your opponent, he/she is not even obligated to respond to your request. It is inappropriate to criticize your opponent for not giving the takeback. ICC will not tolerate harrassment or complaints against an opponent who would not give a takeback.

See Also:
Playing the game
The Game Window
takeback -- command line help