Play the World is the first official expansion for Sid Meier's Civilization III. It adds new cultures, units, and scenarios to the original game as well as several multiplayer modes. In Turnless mode, turns are taken simultaneously by each player and a turn ends when the turn timer runs out. In Simultaneous mode, turns are taken at the same time and when all players are done making their moves (or the optional turn clock runs out), the moves are made and units and buildings are produced. Classic mode is where each player takes their turn separately just like in the original Civilization III game.