If we knew how Derren performed his illusions it would take all the fun away! But it does have a lot to do with auto-suggestion, as el duerino mentions, and NLP (neuro-linguistic programming). There are loads of good books on NLP which can give you some idea as to how a lot of his 'tricks' work. I'm not sure why Donkey thinks him a 'fake' as Oneeyedvic is right in saying that Derren openly states at the beginning of all his TV shows and live shows that he uses illusion, misdirection and showmanship to achieve everything he does. I've also seen him live and all his illusions are 100% more impressive than those emails Donkey mentions. Nobody has any proof that the bullets he used in Russian Roulette were 'fake' - howevre, it should be borne in mind that if you put a gun containing only blank bullets to your head and pull the trigger, it will still kill you. And it's fascinating that secretspirit found him slimy and creepy in real life as I left the show having fallen completely in love with him! I work in theatre and know he will be touring again in Spring if anyone wants to see him for themselves.