What changed?

Materials:
 * N/A

Instructions:
 * The group chooses one person to be the guesser. The guesser must try to remember how the classroom is at that moment, including the pose and placement of other students, what they are wearing, etc. The guesser then leaves the classroom and the players inside have some time (usually one or two minutes) to change three things in the classroom. They have to be noticeable changes, so just moving stuff to slightly different places is not enough. Once everybody agrees on three changes, all players in the classroom return to their original poses and call the guesser back into the classroom. The guesser then has some time to try to guess the changes that were made.