Purdling is a version of Russian Roulette. It's for people with nut allergies, and is played with a packet of Revels. As you may know, there are many different revels but only one with nuts in it. The trick is for these people to eat the other ones. There are coffee Revels, toffee Revels, and many many more. Can you avoid the nutty one? You better bloody hope so!