Practice pushing the limits of spontaneous response.
Although not the same game Numbers Change in the book. (pg. 407), Viola had us play this game several times. The aim is to enhance your impulse to respond instantly. I think also it gets everyone used to working at pace faster than the head can deal with, which makes making mistakes fun and part of the game. (nothing you should bring up to players though as ‘a lesson’ lest you put the focus on accepting failure and not just having a really good time) A great warm-up and really fun.
EGOCENTRIC: Fear of no support from others or from the environment, mistaken self-protection.