One more "I only read MG, not BW" question...

[doycet]

... what the hell is Artha? I get that it's collectively referring to a subset of character attributes, but which ones?

[Rafe]

Artha is the Burning Wheel (and Empire?) reward point system, consisting collectively of Persona points, Fate points and Deeds points. Each type is rewarded to players depending on Beliefs (and goals) and Instincts, and roleplaying. The system is pretty cyclical: You get into situations that involve your Beliefs and Instincts, often using various Artha to pull stuff off, and then you're rewarded for doing so.

They're like Action Points that can be used in different mechanical ways, basically.

[Aramis]

Fate and Person are Mouse Guard's artha. BW and BE add Deeds, whid functions like a level 3 trait... but is bloody rare to earn.