The rules are simple. Player 1 types a key without Player 2 looking. Player 2 types a key without Player 1 looking. If Player 2 typed Player 1's key then that key is "locked" If Player 2 didn't type Player 1's key keep going. If Player 1 typed Player 2's key without the key already being locked then that key is locked First player to type a locked key loses
It only lets you type 1 key, if you pressed none or more than one it will be your turn until you type 1 key