Quick, while everyone is focused on the 5.24 PHB...

[TheHand]

My first non D&D game was Gamma World followed closely by TSR’s Marvel Super Heroes (and also the Indiana Jones rpg before it retired into it’s second life as the Diana Jones award).

But my first non-TSR rpg was the wonderfully obscure James Bond RPG.

By the end of the 80’s I’d played RIFTS, Shadowrun, Mechwarrior, Stormbringer, and Champions but the order all blurs together.

 

[Distracted DM]

My first experience was AD&D 2e being ran at a game store. But I think my first non dnd was a few years after that, my friend ran a 40k hack of Warhammer Fantasy 1e, the rules were all printed out on copy paper