FrogReaver
The most respectful and polite poster ever
None of this is true.
Actor stance requires what it say: that the action is declared drawing on the mental states of the character, rather than for some other reason to which the player then retrofits the PC's mental states.
Here, the reason the action is declared is because the character knows they are lost in the dungeon and the character knows there are strange runes and the character cunningly judges that the runes might reveal a way out.
Actor stance play doesn't require GM pre-authorship of backstory. And your statements about your feelings may be autobiographical for you (though I'm not sure what actual play experience they are based on), but I can assure you that they don't generalise.
Well, I call that actor stance. It's what happened in this case.
An Orc appears to the characters in the fiction as a physical threat. The players respond by doing a whole lot of calculations.
The action resolution system in MHRP also involves generating and manipulating random numbers.
In actor stance the actor doesn’t impact fiction outside his character other than what his characters actions could fictionally cause. In the runes example he does and with the knowledge he’s doing so.