During a recent game, our party came under attack by a Big Bad. The DM introduced it in a suitably epic way- the area we were camping on sank 10 feet per round into a massive pit, until there was room for the Gargantuan creature to stalk over and begin pounding us into the dirt. After one round of attacks flat out killed the party's pet NPC paladin and dropped the other front-line fighters to half-strength, it became clear that this was a fight we were intended to run from.
We did not. In fact, we won, though I'm not sure we should have.
Our defense relied heavily on a casting of Leomund's Tiny Hut, which had already been in place for two hours when the fight began. Per the spell:
A 10-foot-radius immobile dome of force springs into existence around and above you and remains stationary for the duration. The spell ends if you leave its area.
Creatures and objects within the dome when you cast this spell can move through it freely. All other creatures and objects are barred from passing through it.
Now, we interpreted that to mean that we could fire missile weapons through the hut with impunity, and that we could even make melee attacks through the hut, as it lists no thickness for the dome and our characters and their weapons could "move through it freely." This strikes me as a bit OP for a third-level spell, but the casting time implies that it isn't normally intended to be used in combat anyway. I invite comments on the legality of that tactic, but my real question is this:
Should Leomund's Tiny Hut have failed immediately?
I am aware that previous questions have addressed whether Leomund's Tiny Hut works on a moving surface, but this question differs in that the surface in question was normally stationary. This wasn't a ship or an iceberg moving- this was the ground beneath us suddenly sinking. Should we have treated the ground as though the hut was cast on a moving area, or would it have been more accurate to treat what happened as slowly falling out from under the hut? If the latter is the case, and the hut is a dome, I believe the spell would have ended the moment the last of the caster passed under the bottom edge of the dome. Does this sound correct?