tiny hut

[sreservoir]

as I read it, it seems to be one of the more useful defensive spells at early levels, giving total concealment and relatively useless temperature control. it also lasts much longer than displacement and isn't actually negated by anything as long as you can get eight other creatures to pile in with you.

are there any conditions of its use that prevent it from being at least as useful as blur or displacement?

[Greenish]

It's immobile, and you need people to pile in or the enemies can just walk in. Other than those, it's pretty good. (Of course, enemies with AoE will just laugh at your full concealment while you pile in small area.)

[sreservoir]

ah, right. sphere, not emanation.