I get that on the active player's turn they get to spend any advantage and triumph they roll (and that the GM gets to spend any treat and despair)... p. 205, step 5.

I also get that the GM has the option of letting players spend threat and despair rolled by NPCs (seems only fair)... also p. 205, step 5.

But, what happens when an NPC has advantage and triumph (i.e., does the GM get to spend it in this instance)? I could not find anything explicit on this, but it seems the GM should be able to spend it to activate critical hits, assign boost dice, etc. (i.e., the GM is considered the active player for the NPC). Is this correct? Can someone point me to a page in the rule book that deals with this one way or another (either implicitly or explicitly)? Thanks!

p.s., Have read through the book and done several searches, but couldn't find an answer to this exact question. Sorry if it is there and I just missed it.

Yeah, the GM spends it. I'm not sure I can find a direct source, but this is the closest I could come. I wasn't going to scan the whole book because the answer is pretty obvious.

EotE CRB page 205:

"the player controlling the activated character determines how his character spends [Advantage] and [Triumph]"

The GM is a player, ergo, the GM spends NPCs' Advantage/Triumph.

You are correct. I can't point you to a specific page reference, but the GM spends advantages and Triumphs for NPCs in the same way players do for their own characters.

This is simply a logical extension of the examples given in your main post.

For player characters -> the players spend advantages, the GM spends the threats

For NPCs -> the players spend the threats, so the natural extension of the rule is that the GM spends the advantages.

Hope that helps!

Yes, I saw that.. wasn't sure if the GM counted as a player. But, it makes sense that they would be. Thanks!

The rules are intentionally vague sometimes. When in doubt, jsut apply common sense. You can't go wrong with that.