Wall of Darkness

WALL OF DARKNESS
School illumination (evocation) [shadow];
Level sorcerer/wizard 5
Casting Time 1 standard action
Components S
Range medium (100 ft. + 10 ft./level)
Duration concentration plus 1 round/level (D)
Saving Throw see text; SR yes
You conjure a wall up to 10 ft. tall and 10 ft. long per level, or a sphere or hemisphere with a radius of 5 ft. plus 1 ft. per level. A wall of darkness cannot be seen through with any sort of vision, magical or otherwise, including divination spells up to 5th level.
While dimension door and similar spells can bypass the wall, anyone who attempts to physically pass through it immediately sustains 3d6 + 1 hp/caster level (maximum +20) hp cold damage and must make a Fortitude check or take 1 point of Strength damage.
If the spherical or hemispherical construction of the wall is used to trap a victim, then a Reflex save allows the victim to avoid imprisonment.
A light spell can weaken a wall of darkness, reducing damage sustained by those passing through it to 1d6 +1 hp/caster level and eliminating the Strength damage. The damage reduction and elimination lasts only 1 round. Daylight completely negates a wall of darkness for 1 round. Sunburst dispels a wall of darkness.
A wall of darkness can be made permanent with a permanency spell. This costs 5,000 gp and requires minimum caster level 10th.