I don't think the specific effects of going aggro are subject to a lot of
interpretation at all (AW p 193):
When you go aggro on someone, roll+hard. On a 10+, they have to choose: force your hand and suck it up, or cave and do what you want. On a 7–9, they can instead choose 1:
• get the hell out of your way
• barricade themselves securely in
• give you something they think you want
• back off calmly, hands where you can see
• tell you what you want to know (or what you want to hear)
Going aggro means using violence or the threat of violence to control somebody else’s behavior, without (or before) fighting. If the character has the drop on her enemy, or if the enemy won’t fight back, or if the character is making a show of force but isn’t disposed to really fight, it’s going aggro.
On a 7–9, the victim can still choose to cave or to force the character’s hand and suck it up.
If the target forces the character’s hand and sucks it up, that means that the character inflicts harm upon the target as normal, determined by her weapon and her subject’s armor. At this point, the player can’t decide not to inflict harm, it’s gone too far for that.
The controller of the character who is affected - which will be the GM, if that character is a NPC - has to
decide what the character does, within the parameters set out in the rules. This has been a part of RPG rules for a long time: for instance, the 1977 edition of Traveller says, in its morale rules (Book 1 p 33), that "a party of adventurers (player or non-player) which sustains casualties in an encounter will ultimately break or rout if it does not achieve victory. . . . Average morale throw is 7+ to stand, or not break." When morale is lost, the controller of the character who has failed the throw has to decide what happens - do they run, or surrender, or fall to the ground weeping? - but the rules themselves are clear.
I don't think that these sorts of rules - in AW or in Traveller - are particularly abstract, either. Details in the fiction don't cease to matter. In Traveller, for instance, the person who controls a character will normally have regard to the fiction in deciding what that character does if their morale is lost. The examples of
going aggro in the AW rulebook make the details of the fiction highly relevant:
Marie walks up behind Joe’s Girl and pokes her in the ribs with her scalpel. “Come with me,” she says. She misses the roll, though, so I get to make as hard a move as I like in response. I choose to inflict harm and (bonus) put her in a spot. “Damn, Joe’s Girl is fast,” I say. “She slams you in the face with her elbow — take 1-harm — knocks you down, kicks your scalpel away, and by the time you realize what’s happened she’s kneeling over you with her pistol up under your jaw. What do you do?”
Keeler’s hidden in a little nest outside Dremmer’s compound, she’s been watching the compound courtyard through the scope of her rifle. When I say that this guy Balls sits down in there with his lunch, “there he is,” her player says. They have history. “I blow his brains out.” She hits the roll with a 9, so I get to choose. I choose to have him barricade himself securely in: “no brains, but he leaves his lunch and scrambles into the compound, squeaking. He won’t be coming out again any time soon.” I make a note to myself, on my front sheet for Dremmer’s gang, that Balls is taking himself off active duty. I think that we might never see him again.
Bran yells at Fleece, calls her . . . stupid . . . and threatens to push her off the roof. He hits the roll with a 12. “She falls to her knees, she’s crying,” I say. “She’ll do whatever you want. Jesus Bran, you’re a piece of work.”
I don't see what fiction is being elided in these examples.
Well, at least in the versions of D&D that I play, there is a rule for trying to distract an owlbear with honey so as to escape it. From Moldvay Basic p B24:
If characters wish to evade and are slower than the monsters, the DM must decide what the monsters will do. Use the Monster Reactions table to find the actions of the monsters. A low score means that the monsters will pursue, and a high score means that the monsters will let the party escape. . . .
PURSUIT: . . . Monsters will chase evading characters only as long as the characters are in sight. Evading characters may be able to slow this pursuit by dropping things. Unintelligent monsters will stop to eat food 1/2 the time (a result of 1-3 on 1d6).
The "creative" uses of Command are not the same.
The rule in 5e is simply that "the DM determines how the target behaves". Presumably - given that if the save is failed, the victim "must . . . follow the command on its next turn", the GM's decision as to how the target behaves is supposed to correlate, in some fashion, to the word that the caster has uttered; but there is no reference to player (or character) intent - which is a contrast with Go Aggro on a 10+, or getting lucky when distracting a pursuing monster with food in Moldvay Basic; and there is no reference to a general sort of behaviour which is (broadly) consistent with the caster having succeeded in their action - which is a contrast with Go Aggro on a 7-9, or with a failed morale throw in Traveller.
What bits of the fiction - the caster's desires, the target's desires, the gods' desires, possible semantic and/or pragmatic uncertainties, maybe something else - are supposed to matter to the GM's decision about what the target does? The rule doesn't say. Is the GM supposed to have regard to the spell being 1st level, and make a decision commensurate with that power level/resource cost? The rule doesn't say anything about that either.
I think the contrast with other rules that allow influencing or controlling behaviour outside of a participant's "normal" zone of character control, like Go Aggro or morale in Classic Traveller or evasion by dropping food in classic D&D - is pretty clear. Those rules are clear in explaining not only who gets to make what decision, but also what the parameters for that are. Whereas the Command rule just tells the GM to make a decision, without stating parameters, thus encouraging any discussion among participants concerning the resolution of the spell to focus on rules elements (what exactly can a 1st level spell do? what counts as
following a one-word command?) rather than on the fiction. Gygax was clearly conscious of this problem way back in 1978, at least to some extent, which is why his version of the spell description excluded "suicide" as a permissible command, by saying that the target will always construe it as a noun, and gave a non-literal interpretation to the command to "die" (I mean, taken literally, this should fizzle as dying is not normally a
behaviour that someone engages in).
This is why, in this thread, I have been pretty sympathetic to
@Hussar's posts.