Tic Tac Stack is "a clever version of the classic game" of Tic Tac Toe. It adds a dexterity element, more players (up to 4) and the ability to change what is in a box on the board. From the box: "To play: Drop your colored chips one at a time down your ramp onto the game tray. Take careful aim and send your chip rolling, bouncing and jumping onto the play board. Your ramp swivels back and forth to help you aim, but it takes a little luck to get it to land where you want it to! As chips are played they stack on top of each other so you might get covered up on any turn." First player to get three in a row of their color wins.