1. Spell Lists
Rolemaster magic is love/hate, but one thing that stuck from its spell system was the mechanical exposition of increasing spell effects at greater levels. Where AD&D used spell name and then Improved spell name, this was more obvious. AD&D also had a lot of spells in which increased caster level provided better results. Again - nothing new in a revolutionary sense, it was really just the exposition. Spells were presented in lists of levels, with (usually) 23 elements - these lists being a few related spell effects stretched and stepped out. Oh yeah - when a character 'learns a spell', they really learn 3-5 spells...yeesh - OK, I am trying not to explain the magic system wholesale here - the important point is that it got me thinking about scaling spells of similar effect (and has since contributed to my desire to dismiss spell levels entirely).
2. Lists of Spell Lists
There was a body of common spell-craft, but each class (profession in Rolemasterese) that could cast spells had 6 lists of spells (base lists in Rolmasterish) that were generally considered unavailable to other professions.
Reading through Kellri's Greyhawk Spells got me thinking about this - particularly the grouping of the 'named' spells from Greyhawk. I am assuming that at least some of the lists of named spells came from the actual negotiation of the originial players and Gygax, and not so much 'after the fact' padding put in by TSR (I may be wrong) - but the lists are generally themed. The spell inventors weren't trying to make toolkit magic, they were creating spells that fit their characters (though not without utility). (Link to Kellri if you need it - read the CDD's, and everything else too!)
X. An early publication after Rolemaster caught on was the Rolemaster Companion I. This contained a new profession that could build his spell lists from scratch. Oh yeah, and a new realm of magic that basically allowed you to ignore the division of magic into three 'realms'. Have I not mentioned the 3 realms of magic yet? Good! It's a fine concept, an evocative organization tool,
but as soon as they could, they published a supplement that included a way to 'unify' the divergent realms. Rolemaster had a vast profusion of ideas and options, simultaneously publishing ways to simplify and complicate...I feel like Rolemaster is a great game for NPCs.