They are composed of five groups. Each group is going to act out a play in front of other people. What directions can we use for them?

1.It's time to act out the play.
2. As soon as the director says, "Ready. Action!", you have to act in the play.
3. Why don't you act the play out?
4. You have to start acting with your members.
5. Begin acting now.
6. ________________.

[Are the sentences available in a play? Do you have some more common directions?]

I'd use #s 1 and 5, and maybe a variation of 2.

Start acting immediately after (or right after) the director says, "Ready. Action!"

Yes, those sentences can be used as directions in a play. Here are a few more common directions you can use for the groups:

1. Take your positions on the stage.
2. Wait for your cue before starting your scene.
3. Remember to speak clearly and project your voice.
4. Don't forget to stay in character throughout the performance.
5. Coordinate your movements and actions with the other group members.
6. Pay attention to the timing and pacing of the play.
7. Use appropriate gestures and facial expressions to convey emotions.
8. Take note of any specific blocking or choreography instructions.
9. Follow the director's guidance and make necessary adjustments.
10. Maintain good stage presence and engage the audience.

Feel free to use these directions as appropriate, adjusting them based on the specific needs and requirements of the play.