UK twix and US twix are the same. One of the few candies that are. There's a whole confusing combination of mars bars and milky way and three muskateers that masquerade as one another variously by country.

Cluin, I tried that with a pack of m&ms once. My testing methods were not scientific enough though, because the newcomer almost always won, the previous winner having been weakend by the warmth of my hand. I think I need to develop more specialized m&m war equipment. I also often find that mutations have a much thicker shell, thus having a great advantage.