Note: The following is the text of the referenced spell combined as necessary to eliminate the need to read the referenced spell or mechanic. The following is not "core" content or wording and is subject to GM approval. It is not meant to change any mechanics, simply to eliminate the need to look up the referenced spell or mechanic.

Acid fog creates a billowing mass of misty vapors. The fog obscures all sight, including darkvision, beyond 5 feet. A creature within 5 feet has concealment (attacks have a 20% miss chance). Creatures farther away have total concealment (50% miss chance, and the attacker can't use sight to locate the target).

Creatures moving through an acid fog move at half their normal speed and take a –2 penalty on all melee attack and melee damage rolls. The vapors prevent effective ranged weapon attacks (except for magic rays and the like). A creature or object that falls into acid fog is slowed so that each 10 feet of vapor that it passes through reduces the falling damage by 1d6. A creature cannot take a 5-foot-step while in acid fog. Acid fog, and effects that work like acid fog, do not stack with each other in terms of slowed movement and attack penalties.

In addition to slowing down creatures and obscuring sight, this spell's vapors are highly acidic. Each round on your turn, starting when you cast the spell, the fog deals 2d6 points of acid damage to each creature and object within it.

Unlike normal fog, only a severe wind (31+ mph) disperses these vapors, and it does so in 1 round.