Set the clocks to however long you want the game to last. Then, press your button to start your clock before flipping all the sand timers over. Using one hand, you've got to keep the sand flowing by flipping and moving the sand timers to an empty space, one at time. Stay focused and move fast... The instant a sand timer runs out, your opponent gets to hit their button to stop your time and start theirs before jumping right into the sand-flippin' action. Whoever runs out their clock first wins!