Star Wars

From the introduction:

Several people have attempted efforts to create Star Wars RPGs using an old school feel. Many have been inspired by D&D, but none exist within the specific paradigm of the original D&D rules as written. All, so far, have made extensive modifications, from highly detailed combat and weapons rules to ascending AC and even changing the listed ability scores.

These rules are designed to function with minimal changes to the existing D&D paradigm and should be playable by anyone who has access to the original 3 booklets, plus supplements I, II, and III.