As best I can tell,
@Hussar is relying on widespread consensus that RuneQuest, Rolemaster, Chivalry & Sorcery, HERO, GURPS and the like are simulationist RPGs.
They all have quite a bit in common, which mostly reflects how they react against D&D:
*Their rules for PC build tend to produce PCs who are defined in terms that are closer to "total" (ie aspiring to specify everything about this person's capabilities) than the trope-y and limited information provided by the classic D&D class system;
*Their rules for injury involve more than just hp ablation - eg there are rules for wound penalties, knockdown, unconsciousness/"bleeding out", hit locations and the like;
*Their combat rules try to approximate simultaneity of resolution and reduce the abstraction of classic D&D combat while also avoiding the "stop motion" feel of more contemporary D&D combat;
*Their spell rules, if they have them, tend towards power point or exhaustion rules rather than memorisation and/or slots;
*Their overall tone aspires to a type of "seriousness" about the fiction, the setting, etc that is absent from the classic D&D texts (eg OD&D, B/X, AD&D although parts of Gygax's DMG are clearly written in response to and defence against the emerging anti-D&D simulationist aesthetic).
In terms of my post upthread, these RPGs aspire to (1):