Escalation

Players stand in a circle. One player makes a subtle gesture or movement to their neighbor, possibly accompanied by a word or sound. The next player does the same thing, but slightly bigger. And so on around the circle, each person escalating further.

When it can't possibly get any bigger, the next player starts something completely new — small again — and the escalation begins anew.

This trains commitment, physical expression, and the ability to build on others' offers.