Just a couple of things regarding campaign co-op that seem a little inconsistent with normal play. I'm not sure if they're intentional or not. 1) Any cards (not necessarily traits/other mandatory actions) can be played by a character before another character uses a mandatory action. For example, say we have players A, B, C. On B's turn he plays a Laser card, making a malfunction, such as meltdown. Then player C can play a move or attack card if he has it, likewise A can, before B has to play his meltdown. Handy for getting out of the way of a spray. I'm not sure what happens with pvp co-op, presumably the same. In SP the player must play any mandatory action immediately. 2) Quests (proper use of the word 1 hp, handicap, etc.) on adventures that you haven't unlocked (Treasure Hunts) can be played with players who have them unlocked as leader. If the quest is beaten, the follower that does not have it unlocked will still get a gold chest. I don't know whether if they unlock it later it will show as completed. The loot fairy meanwhile refuses to share it's contraband with followers who have not unlocked whatever Treasure Hunt. I am of course a great fan of getting the gold chest for locked quests, but it is a bit inconsistent is all.
2) may be intentional... I know it's intentional that you can use co-op to get quest rewards from ones you've already completed.
A mandatory action is different from a trait. It is like the game is telling you, "You cannot play any other cards with this character. You HAVE to play this card and use up your turn (unless cantrip)."
My understanding is that co-op games are supposed to follow the same rules that regular games do. This breaks that notion by allowing a team to do something else while it has a Mandatory Action, and to my knowledge it's the only thing that breaks that notion (aside from the extra draws to compensate for a missing third player).
Locked content [whether locked by lack of purchase or not having reached it in the campaign] sets the Exhaustion track to Exhausted, preventing loot boosts. Quests have their own track (which is a one-time clear, and thus doesn't check exhaustion at all), which is likely why they're ignoring locked status for the purposes of providing boosts. Good thing to know, though, my groups have been skipping treasure hunt quests when someone didn't own the related content; given that I run with several newer players, I'm sure they'd be glad to benefit from an extra boost
