I'm confused about when you can use CPs. Can you only use them during one of your characters activations or can they be used in your opponents activations. When can they be used and when can't they.

Can anybody help?

CPs can be used anytime any of your charakters are affected by something - be it an attack, a grenade, an ability - and if he has to make a roll (attack roll) or test (Mental test, stamina test for bull rushing, etc.). You can give a character of yours 1 additional movement point for 1 CP or launch a counterattack. you can also use 1 of your CPs to reroll your initiative roll or 1 to set 1 Character on Overwatch.

See Page 24 of the revised rulebook ^^.

Thanks for the help