This came up in another online discussion:
So my girlfriend and I was playing and I managed to put a Fairy Fountain on one of her rooms. She then used the Wreck Room to destroy that room. Is that possible, or is it treated like a Freeze card where you cant do anything to that room and it's competently deactivated. Follow up question just it case it might happen, could you build over it lets say I play "Wild Monster".
My initial response:
Initially in Boss Monster (1), a spell effect was in play until the end of the round, only able to be stopped at the moment of casting by the Counterspell card.
Boss Monster 2 may have some advanced rules in the works.
I think using an effect to destroy the room in question is a valid strategy. Wreck Room, Bottomless Pit and Boulder Ramp would be good examples of cards that destroy the affected room, thus negating the spell itself. I can't find anything that says a spell in play has to remain in play if the affected room is destroyed, nor that the affected room is considered 'locked' due to the spell effect.
As for the follow-up: I'm not entirely sure if that would be possible, but I can't see anything that says anything contrary to it.
The only thing I've seen is that it's unclear if the newly built room would deal damage to a hero within the room if they happen to be in it when the change comes.
Now I'm thinking it all over again, I came here to see what other Boss Monster people think: CAN
a room-destroying action (Wrecking Room/Boulder Ramp) be used to counter a spell-affected room? I can only think of this as being beneficial for the types of rooms where the Hero is immediately killed as well, like Bottomless Pit.