Hold Vapor

This spell allows a wizard to halt and prevent the further movement of any visible cloud or vapor within the spell's range and area. Such clouds include gaseous breath weapons, fog cloud, cloudkill, and incendiary cloud as well as the smoky effects of pyrotechnics. Other objects can pass freely through this barrier so individuals can pass in and out of the gas-filled area. (A volatile gas could be contained by the spell and then safely incinerated by tossing a torch through the barrier.)

The spell lasts for as long as the wizard continues chanting, to a maximum of one hour, at which time the spell fades and the cloud (if it is still there) settles or drifts naturally. The mage can move normally during this period, though if silenced or interrupted from chanting for a full round, the spell will fade and the cloud will be freed.

The hold vapor spell will restrain gas clouds even against magical and natural winds. A creature in gaseous or airlike form (air elementals, djinns, and vampires, for example) can also be contained by this spell. In these cases, the creature being contained is permitted a saving throw vs. spell each round to break through the barrier. Gaseous creatures cannot transform back to their natural states when being contained by this spell.

This spell does not control a cloud of gas, it only contains it and halts its movement.

The material component of the spell is a small balloon or bladder.

Notes: Uncommon spell from the Forgotten Realms setting. Known to be in The Book of Bats.