Significance of Rule Changes in Editions

[Ariosto]

Sure, or translate the base chance to hit into % for use with RuneQuest. Or one could strip away the powers and feats and skills from 4E ... but then maybe some 4E fans would not consider it "just the same game".

 

[Dannyalcatraz]

Count me in as another vote for:

Biggest mechanical change: 2Ed ==> 3.XEd

Biggest fluff/philosophy change: 3.XEd ==> 4Ed

But that latter one is just by a hair, largely because of that gamist philosophy, illustrated in part by (what I perceive as) a retrograde in design theory about PC design flexibility- constraining options in favor of balance & playability.