GURPS

Advanced Dungeons and Dragons, 1st Edition

Conversions:https://www.amazon.com/Official-Advanced-Dungeons-Dragons-Handbook/dp/0935696016/ref=as_li_ss_tl?s=books&ie=UTF8&qid=1513304737&sr=1-4&keywords=ad&d+1st+edition&linkCode=ll1&tag=gamesandgaming-20&linkId=54b8097b19f3e0743dfe138ec4dfb86a

d20 System