2E. True story. PC's entering ground level of a tower. Shimmering "curtain" across the ceiling. BIG Blue dragon sticks his head down through the curtain and breathes on the PC's in the doorway. First PC in the doorway wearing Neclace of Missiles - almost full - fails his save. The necklace fails its save. The dwarf next to him fails his save. The keg of smokepowder in his backpack (100 charges IIRC) fails its save. Dead dragon. Almost TPK. Oh, and the destruction of the tower was seen by our spelljammer crew aboard the Red October in low orbit.

It was actually kinda fun to be involved in such a spectacular destruction. Of course MY character survived.