Sibling Rivalry is a commissioned game from Richard Garfield for the game design textbook "Rules of Play", by Katie Salen and Eric Zimmerman. Players are siblings trying to annoy each other. The game is played on two boards: the challenge board and the score track. By advancing a marker on the challenge board, you can score points on the score track. The first player to reach the end of the score track wins. The heart of the game is a "push your luck" dice mechanism to advance on the challenge board. A player begins by rolling five dice, setting aside ones. Other numbers can be used to advance a pawn along one of five columns, representing Looks, Faces, Tickles, Ouchies, and Teases. After each roll, you can either stop or keep rolling. If you stop and your pawn is the most advanced pawn in that column, then you remove any pawn it passed. If it is not the most advanced, then you remove your pawn from the challenge board. If your pawn has not been removed from the board by your next turn, then you score points for it on the score track. You can keep rolling dice to advance your pawn farther up the challenge board, but when you accumulate three or more ones, your parents have caught you picking on your sibling. Your turn ends and you lose points.