Wall of Ice
Evocation [Cold]
Level: Mage 4; Components: V, S, M; Casting Time; Attack action Range: Medium (100 ft. + 10 ft./level); Effect: Anchored plane of ice, up to one 10-ft. square/level, or hemisphere of ice with a radius of up to 3 ft. + 1 ft./level; Duration: 1 minute/level; Saving Throw: See text; Spell Resistance: Yes
This spell creates an anchored plane of ice or a hemisphere of ice, depending on the version selected. A wall of ice cannot form in an area occupied by physical objects or creatures. Its surface must be smooth and unbroken when created. Fire, including fire spells, can melt a wall of ice. Fire deals full damage to the wall (instead of the normal half damage suffered by objects). Suddenly melting the wall of ice (by reducing it to 0 hit points in a single attack) creates a 10-foot-radius cloud of fog that lasts for 10 minutes. Objects and creatures within the area are treated as if they had one-half concealment (20% miss chance) with respect to one another.
Ice Plane: A sheet of strong, hard ice appears. The wall is 1 inch thick per caster level. It covers up to a 10-foot-square area per caster levels. The plane can be oriented in any fashion as long as it is anchored. A vertical wall need only be anchored on the floor, while a horizontal or slanting wall must be anchored on two opposite sides.
Each 10-foot square of wall has 3 hit points per inch of thickness. Creatures can hit the wall automatically. A section of wall whose hit points drop to 0 is breached. If a creature tries to break through the wall with a single attack, the DC for the Strength check is 15 + caster level.
Even when the ice has been broken through, a sheet of frigid air remains. Any creature stepping through it takes 1d6 points of cold damage +1 point per caster level.
Hemisphere: The wall takes the form of a hemisphere whose maximum radius is 3 feet +1 foot per caster level. It is as hard to break through as the ice plane form, but it does not deal damage to those who go through a breach.
The caster can create the hemisphere so that it traps one or more creatures, though these creatures can avoid being trapped by the hemisphere by making successful Reflex saves.