RuneQuest wa mechanically mostly developed by Steve Perrin as an outgrowth of his tinkering with D&D. You can see a lot of the basic stuff in his contributions to Alarums & Excursions.RuneQuest, really? Palladium FRP definitely, but the RuneQuest I'm familiar with is the progenitor of Basic Roleplay System (same core as Call of Cthulhu). It DOES have ability scores mostly on a 3-18 scale (with 5 of the 7 overlapping with D&D), but it's a % skill-based system rather than class & level, HP don't increase over time, spells use mana points IIRC... Was original RQ closer?

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.