His text reads:

Quest Action : Spend 1 [spirit] resource to put Bofur into play from your hand, exhausted and committed to a quest. If you quest successfully this phase and Bofur is still in play, return him to your hand.

My Question: if I don't quest successfully and he is still in play, then does he remain in play? Or did they mean to imply that he leaves play?

Not that I often set out to not succeed at questing, but it it gets me an ally for 2 less resources, I may consider it some time (especially if I can hit the sweet spot of exactly matching threat ...)

yes that is what it means, if you fail the quest he stays in play.

I also interpreted it that way. Once something is put in play, it stays in play unless something on the card says otherwise (like Gandalf or Sneak Attack). I think Bofur is a great Spirit card, especially if you run Dain (or one of your teammates do). For 1 ressource, you can add 3 willpower, and if it doesn't work, you have a new ally at a discount. Pretty neat !

In addition, a friendly reminder: if your commited will power total = threat total in staging area, you neither quest successfully nor unsuccessfully, so Bofur will stay, too!

Thanks for the responses - Bofur (together with Dain) is going to be seeing a lot of use in my dwarf themed decks.

Angus Lee said:

I realized that - hence my comment about hitting the sweet spot of exactly matching threat.