To play Ninja, every player stands in a circle putting one of their arms into the middle. Everyone then shouts ‘Ninja!!’ and pulls their arm and body out of the circle in one move. Then, going round the circle, each player has a turn where they can make one move to try and quickly tap another players arm, the other player is allowed to move to try an escape the arm tap. If the arm is tapped then that arm is ‘out of the game’ and the player must put that arm behind their backs.
Players go out of the game if both of their arms are tapped, the winner is the last player with one or two untapped arms!