Mistbound says "Discard 2 cards. If you do, you may select a deck. Cards from that deck cannot be played until the start of your next turn."
Forced Deployment (ONGOING) says: "When this card is destroyed, take all of the minion cards from the villain trash and put them into play. At the start of the villain turn, destroy this card."
The Rulebook defines a deck as: "The set of cards associated with a specific hero, villain or environment. All cards in a deck have a uniform back."
On one round, Voss played Forced Deployment. This meant that on his next turn, he was going to get all of his minions back. Nightmist played Mistbound and chose Voss' deck, saying that no cards can be played from that deck. The definition of a deck seems to state that cards in the discard are considered part of the deck.
One argument is that the cards from the trash could not be 'played', so the Forced Deployment went off, but had no valid targets.
The opposite argument was that the cards were not being played, but they were being put into play.
Two things. First, the term 'deck' tends to be overloaded. Outside of playing a game, a deck is considered all cards containing the same back. However, inside a game, a deck is considered the face down cards where one can draw/play cards. It's even stated that if a deck is empty and you need to play/draw cards from the deck, you shuffle the trash, and those cards now become the deck.
The second part is that entering play is not playing (though playing is entering play). So, given the cards come from the trash, and that the cards are entering play, twice Mistbound would not effect Forced Deployment.
Yeah, Mistbound would stop voss from playing any cards from his deck. However, Forced Deployment doesn't cause cards to be played. It just dumps the contents of his trash (well, the minions) into play. As JayMann says, in-game a "deck" is the stack of face-down cards that heroes/villains/environments draw/play from. You have a deck, a discard pile, a trash pile, and cards in play. And if you're a hero, a hand (cards that have been drawn but aren't in play).
Similarly, regarding the Mistbound thing, this also wouldn't stop the Operative from bringing an Underboss into play at the end of the villain turn when you're fighting the Chairman. This is because it says "reveal cards until you get an Underboss, then put it into play" or words to that effect. Revealing isn't the same as playing, so can still happen if you can't play/draw cards. So if the Adept was prevented from drawing cards, he could still loot his deck by means of Arcane Cadence since this specifies that you reveal the top five cards of your deck, rather than draw them.
i actually beleive Christopher has stated that the Trash is a deck and can be targeted. I can't find the quote so I may be wrong but people with smarter quicker searching skills than me may be able to find it.
Whether his trash can be targetted by Mistbound or not, it wouldn't help in this case. Mistbound says that cards cannot be played. Forced Deployment doesn't say they're played, it says that they're put into play. A subtle difference, but an important one.