Simon says

1. Give the students simple commands: Stand up! Turn round! They must obey these commands only if you say 'Simon says' first; if you omit this prefix they should ignore them. Any student who performs a command that was said without 'Simon says' loses a 'life'. They have three lives, after which they are 'out'. Later, students themselves may give the commands.
2. As a variation, omit the 'Simon says' rule; instead, give a command and at the same time do an action which may or may not correspond to it. The students have to do what you tell them, not (necessarily) what they see you do.