Rock-paper-scissors: nifty tools and assignments

In the childhood game of "rock-paper-scissors", two participants select one of three different gestures. The selected gestures are then compared using the following rule set: rock crushes scissors, scissors cuts paper, and paper covers rock. Ties are broken by repeating the game as needed. The game can be played until the first winner is determined, or in repeated rounds (e.g. best two out of three).