Rules:
You have to have a partner
Have high pain tolerance
You have to be fast and sneaky as heck.
You must wrestle

This is how it goes.
One person has a coin, while the other person watches as the coin is put on the first person's hand and then they flip their hand. In order to keep the coin with you, you may grab it and the second person can wrestle you for it and even try to force your hand open. To win you either keep the coin safe, or the other person takes it and goes quickly away from you. You do not do this standing. I repeat. YOU DO NOT DO THIS STANDING! You are either on your knees, legs, or laying down, preferably on knees.

Do you see why now? I kept winning and we both ended up hurting each other XD