Exchange harm for harm

In the list of MC moves, there's "Trade harm for harm (as established)."  On p 119, there are a couple of examples that aren't entirely clear to me, but I think are meant to show that the MC can just say "okay, the outcome is you took a bullet for 2-harm, and one of their guys is down and bleeding", without anyone needing to roll.  It also says to see the Harm & Healing chapter, but if there's anything else there about trading or exchanging harm, I don't see it.

So, how do you guys play it?  "Trade harm for harm" is just like two "Inflict harm" moves, that happen to apply to people on opposite sides of the fight?  Is there any reason that the harm exchanged should be of the same amount?  What does "as established" mean, where it's listed in the MC moves?

At first I thought "exchange harm for harm" might be meant to apply more to a situation more like, "well, the rifle normally does 3-harm, but I'm going to lower it to 1-harm and also smash your relic iPhone."  But as best I can tell, that's not what's implied in the examples.

So, how do you guys play it?  "Trade harm for harm" is just like two "Inflict harm" moves, that happen to apply to people on opposite sides of the fight?  Is there any reason that the harm exchanged should be of the same amount?

That's a, perfectly reasonable, but wrong reading of "Trade harm for harm", it's not a numerically equal thing, but an equal "action" thing:

PC1: "I'm slashing you with my knife... 2-harm"

PC2: "And I lets loose with my shotgun at you point blank... 3-harm"

It's dealing your harm (as established) as they deal their harm (as established); like just getting into a fist fight with someone, without any seizing or threats in play.  It's just "plain" fighting someone with them fighting back.

What does "as established" mean, where it's listed in the MC moves?

That just means the end value of harm inflicted after starting harm value of weapon/attack has modified by any armour, moves, and/or gang size in play.  Think of it as "actual/final harm value inflicted".

Does that make it clearer?

I have always read "as established" to mean "as established in the fiction"; i.e. the amount and character of the harm that is inflicted is the clear result of the dangers present and described in the scene (or in the rare case of a hidden sniper or trap, as present and 'described' in the MC's head.) The main point being that whatever harm you are inflicting should not come as a surprise to anyone, but be a natural consequence of what has already been set up in the story.

This also emphasizes the fact that the primary factor in how much harm is done is what is actually happening, not what is on a character sheet, etc. The PC may have a 3-harm assault rifle loaded with armour-piercing rounds, but if the fiction describes her smashing someone in the face with a rock, then that's the action that should decide how much and what type of harm she inflicts.

Right. And armor works that way, too, of course.

You have a sweet bulletproof vest and such, cool. You get into a wrestling/fist-fight with the gang members, no, your armor doesn't apply. Oh, wait, you're actually completely covered head to toe in rigid plastic and scavenged metal? Well, dang... then, yeah, it totally counts, my bad.

P.S. You are a weirdo, Armor Man. God bless ya.

Awesome, thanks.

For reference, harm as established is defined towards the bottom of page 15.

"Typically, when a character takes harm, it's equal to the harm rating of the weapon, attack, or mishap, minus the armor rating of the character's armor.  This is called harm as established."