I talked like I knew what I was talking about in the last post, and (in a twist that shocked no one) it turns out that exact situation came up in the game on Friday night.
Setup: chest is a small room, chained to the walls - not to lock the chest but to keep it there. Bolts in the stonework, heavy chains with inscriptions (non-magical) in ancient languages. Claw marks on the ceiling.
These aren't exact quotas, but pretty close based on my quickly scribbled notes:
Player: "I want to open it but this is clearly a bad idea"
Player 2: "This is a trap ... but what is in there? omg. OPEN IT!"
Player 3: "Dude, dude, dude. Relax. We don't HAVE to open it. But we should open it."
Player 4: "Maybe it has a head in it?"
Player 5: "I get as far away as I can in the hall while encouraging someone else to open it. Don't we have hirelings for this kind of thing?"
Players 1&3: "I like my henchman - no way! You open it."
Player 2: "The Winter Queen isn't keeping the not-dead king's head in here. But what the fuck is she keeping in here?"
Player 6: <chuckling quietly and grinning> "Consequences be damned - open it, Argento!"
The in-game tension from describing a weird thing got the players all amped up, which was great. The more they fucked around with it without opening it all the way increased the ominous sense of danger - because there was something terrible in there.
It was glorious. They opened it.