“I doubt the players would want to be kicked off of ledges willy-nilly themselves,” is my go-to logic for a “fictional causality first” game. In such games, I tend to find abstractions like AC and HP more confusing than helpful, unless they’re defined in very clear (and usually simple) terms. It sounds like this game might be something else, though! “The game already tells us how hard it is to defeat the tick, with its AC and HP. Stunting bypasses the HP, but not the AC – that’s double-dipping,” is a logic that looks to the mechanics to inform the fiction.
As a player, I can work with either version, but I’d want to know very clearly which we’re using, A or B!
A) If envisioning the fiction leads us to conclude that punting the tick is easy, then we punt the tick with no roll, but must be very careful never to put ourselves in that same fictional situation, because if we do then we too may be punted without a roll.
B) Armor Class tells us something meaningful regardless of the fiction as otherwise described. If we want to refer to our vision of the fiction, that vision must include what the AC tells us, such as that a monster is not so easily kicked off a wall. When the situation is reversed, our own AC scores will also tell us how easily we might be kicked off a wall.
And of course there’s a third option:
B2) The AC score will factor in, but based on how we apply situational bonuses, the fictional specifics might utterly drown it out (-15) or barely impact it (-1). If the game provides objective measures for such bonuses, then we’ll have to reconcile our vision of this specific incident with the game’s arbitration of this general type of incident.
That’s my assessment. What follows next is my personal taste:
If I’m playing a game where the people at the table care whether I can or can’t or maybe can kick a monster off a wall based on the fictional positioning of being up on a wall, then:
- Pure mechanical abstraction, while fair, is never actually satisfying.
- A highly subjective combo of mechanics and judgment is sometimes satisfying, but sometimes not, and sometimes seems unfair. It can also be hard to communicate. (This is B above.)
- If the table can quickly reach agreement on what’s plausible (and then, if multiple outcomes are plausible, use a simple method to resolve which outcome actually occurs), that’s ideal. (This is A above.)
I am also happy to play a game where my ability to punt a monster has little or nothing to do with the fictional positioning of being up on a wall! In that case, it can be pure mechanics, or story logic, or karma points, or part of a script, or a coin flip, or whatever suits the kind of game we’re playing. But if we want to keep caring about that wall, I’ll usually prefer option 3/A.