MortalPlague
Adventurer
5E - themes
Oh, I sure hope so. If that's the enduring, memorable part of 5th Edition, I'll be very happy.
5E - themes
As someone who played all the editions, I would say the 1E defining sub-system was Races.1E is a bit trickier; as a descendent of OD&D, which I've never played, I don't feel qualified to make a guess.
Actually, I think most subsystems creep in at the end of the previous edition. Themes are in 4E, powers showed up in Book of Nine Swords for 3.5, etc. So I might lean more towards non-weapon proficiencies for 2E, but obviously this is all totally subjective.We could also say non-weapon proficiencies but, if I remember correctly, they crept into the later years of 1E.