AD&D 2nd Edition

Range: 30 yards
Components: V, S, M
Duration: 4 rounds + 1d6 rounds
Casting Time: 2
Area of Effect: Special
Saving Throw: 1/2

And incendiary cloud spell exactly resembles the smoke effects of a pyrotechnic spell, except that its minimum dimensions are a cloud of 10-foot height by 20-foot length and breath. This dense vapor cloud billows fourth, and on the third round of its existence it begins to flame, causing 1–2 points of damage per level of the wizard who cast it. On the fourth round it inflicts 1d4 points of damage for level of the caster, and on the fifth round in this again drops to 1–2 points of damage per level as its flames burn out. Any successive rounds of existence are simply harmless smoke that obscures vision within its confines. Creatures within the cloud need to make only one saving throw if it is successful, but if they fail the first saving throw, they roll again on the fourth and fifth rounds (if necessary) to attempt to reduce damage sustained by one half.

In order to cast a spell, the wizard must have an available fire source (just as with a pyrotechnics spell), scrapings from beneath a dung pile, and a pinch of dust.