It is highly recommended, but school is a reality-driven place. You may be walking down the halls with the students and decide that playing a Game would be a good idea. So, you could use a wristwatch, a phone, or you could even play the Game from point A to point B. If your students are experienced with the Game, it is a great job for students to be selected as “timekeepers.” That is, you can tell the student, “Timekeeper, please give us 30 seconds for putting away our books and materials,” or “Timekeeper, please set the timer for a 30-minute Game, and tell me when you are ready for me to announce the Game.”