how do brainers impulses work?

I'm looking at the playbook, and I am having a hard time on figuring out just what they mean.

The word Impulses within the book is used primarily for threats.

Are you having trouble understanding how brainers function in general or how a few of their specific moves work?

No, I think I understand how they work, just a little curious about some things.

When you say "is used for threats", do you mean me threatening them, or that's how I view them?

I think the confusion comes from the use of terminology that is very specific to Apocalypse World.

By "Threats" Ebok is referring to the standard AW terminology for "the opposition."  Warlords, Grotesques, Landscapes, Brutes, etc.  Threats act under certain "impulses" (i.e. the "Prison" Landscape threat has an impulse to trap, to contain, to prevent escape).  These impulses simply serve as an easy reminder to the MC that that's what this particular Threat is all about.

The Brainer on the other hand is a PC playbook type.  It doesn't have "impulses" the way a mechanical Threat does (largely because the Brainer is acting under player control, and gods only know what impulses the player has ;) ).  So I think we don't understand your question.  What is it about how the Brainer works with which you're having trouble?

Nothing, now. Since it was on my character sheet, I thought it only referred to me.

Look at the back of the Brainer playbook, under "Additional Rules."

Vincent, being a bit coy here, has put the MC's text for Threat Impulses there. He says "You can’t use these — they’re the MC’s — but you might find them interesting." As indeed a brainer certainly might. It's like saying, hey, you're a Brainer, you know stuff regular people don't, like for example how all these various threats think.

What you do with that information is up to you.

John's right.

For example, a hunting pack has the impulse to victimize anyone vulnerable.
If you can guess (or somehow figure out!) whether some group is a hunting pack, you can for sure make use of that info.

How? Show them someone vulnerable?
Vulnerable how? Well, you'll have to figure that one out.

- Alex