Fog Cloud (spell)

Fog Cloud is a spell that creates a large circle of misty vapour that covers much more area than the wall of fog spell, though it occurs in a single mass. Like its 1st level predecessor, it also limits visibility within the affected area, including infravision and ultravision. The fog may be created anywhere, over land or water, passing through the middle of buildings or along a corridor, as high or as deep as the caster wishes within their ability.

Fog Cloud

Range	60 ft. +10 per level
Duration	3-12 rounds +1 per level
Area of Effect	20 ft. wide dome, +5 ft. radius per level
Casting Time	1 round
Saving Throw	none
Level	illusionist (2nd)

The cloud forms as a continuous body of dense vapour, its edges soft but clearly bounded, occupying the full space into which it is cast. It does not cling to surfaces but hangs suspended, maintaining its cohesion whether spread across open ground or confined within enclosed spaces. Within structures, it conforms to rooms, passages and openings, dividing and rejoining as necessary while remaining a single mass wherever space permits.

The fog is completely harmless, though creatures with an intelligence of less than 4 will instinctively go to ground within it, remaining still or seeking cover rather than attempting to move through the obscured space. When the spell’s duration comes to an end, the vapour does not vanish at once but thins gradually, requiring five complete rounds to evaporate. During this time, visibility improves steadily, extending by one hex each round, until the cloud has fully dissipated and normal sight is restored across the affected area.

Visibility

Within the spell’s fog, visibility equals one hex exactly; combatants can therefore fight hand-to-hand within it, at no penalty to hit or damage, but missile weapons are useless. Attack spells may be discharged blindly into the vapour, while audial-based spells, such as chant, audible glamer and magic mouth, are strengthened by the obscurity, their points of origin concealed within the cloud.

In any hex adjacent to the fog cloud, visibility equals one hex when looking into the fog. When looking along the edge of the cloud, visibility extends to three hexes, as the boundary of the vapour provides a clearer line of sight parallel to its extent. Visibility is completely normal when looking away from the fog.

Dispersal

A wind-based spell requires three full rounds to disperse the fog cloud. This is due to the illusionary component of this spell, which differs from the wall of fog. Since a gust of wind spell lasts only one round, the fog cloud is immune to it; in fact, it requires consistent wind force greater than 3 to disperse the effect, trebling visibility the first round to three hexes, then doubling for each round thereafter, to six, then 12 hexes, until full visibility occurs on the fourth round.

See also,
Darkness (spell)
Haze (cantrip)
Murk (spell)