Day 20 D&D 40th Anniversary Blog Hop: First non D&D RPG you played

The first RPG I played other than D&D was Gamma World. It was the first edition boxed set, if I remember correctly. We enjoyed it, but didn't play it a lot. The most memorable campaign was one that actually started out as a D&D game, where our arch enemy was a hyper-intelligent gargoyle, Fontaine. When we eventually tracked him down, we discovered that he wasn't a gargoyle at all. Fontaine was a Gamma World mutant who had discovered a portal between the worlds. Naturally, we followed him back to his world in order to put an end to him and his nefarious plans.