I tend to subscribe to the idea that in competition or self defense anything is game but in training with your partner there are things you either shouldn't do or should use a good deal of restraint when doing to avoid injury. Specifically I think it is a load of crap to wrist lock your training partner with any real strength behind it. Wrist locks get applied so fast you almost don't have enough time to tap. Certainly you need to be prepared to defend but that doesn't mean once you get your partner in a wrist lock, crank it as hard as you can until they tap. Several times I have gotten a good grip and been able to apply a wrist lock and I will tell my partner "I am about to do a wristlock" then I gradually apply pressure to give them a chance to tap.
tbone