Informal, relaxed ones. The people I play with say stuff that they think is fun, or cool, or fits their assumptions about their PC and the fiction.
Here's an example, reposted:
One player - playing a Chaos Sorcerer - takes as a premise of declared actions that energy from a dead fire drake can be harnessed and channelled into a jewelled horn, to turn it into a magical Fire Horn. Another player - playing a wizard/invoker in the service of Erathis and the Raven Queen - takes as a premise of a declared action that his Sceptre of Law can control chaotic energy, and tame it into a usable portal.
I've also posted, not far upthread, an example of a third player having his PC speaking a prayer against the undead; and further upthread the example of the player of the wizard/invoker deciding which magical operations and effects count as "rituals" and which don't.
Well, I think AD&D is even less well-suited for simulationist RPGing - as is demonstrated by the fact that the classic simulationist FRPGs (RQ, C&S, RM) are all reactions to it. RQ and RM drop hp ablation combat, drop spell memorisation of the D&D sort, and incorporate skills in some fashion - thereby dropping/changing those aspects of classic D&D that are seen as the most jarring from a simulationist perspective. I'm not as familiar with C&S, but my understanding is that it makes similar sorts of changes, especially to magic.
But a lot of people who play AD&D claim to do so in a simulationist fashion. Likewise for 3E and 5e, which are just as unsuited.
AD&D is also ill-suited, in my view, to DL-ish epic/romantic FRPGing, yet is the prescribed system for that!
So I tend to take your "it makes sense" with a bit of a grain of salt!