1) Getting rid of professions (too artificial for my taste), skill costs depend on stats, 5 skill specializations (RoCo V) to reflect profession.
2) Getting rid of levels (almost; too artificial), PCs earn 1-15 XP per session to develop skill ranks directly.
3) Luck rolls: a PC may re-roll any roll once (e.g. suffered crits) but loses 3 XP (subtracted from the rewarded ones), saves life but not always.
Despite these rather crude simplifications it still feels like Rolemaster