Wall of Ice (spell)
Wall of ice is a spell that creates a cold sheet of natural frozen water, as high, wide and thick as desired according to the area of effect given. The wall's use permits defense or the trapping of large creatures within its environs, though in comparison to stone or iron, the ice wall is comparatively less resilient against attack.
| Range | 10 ft. per level |
| Duration | 10 rounds per level |
| Area of Effect | 500 +100 cubic ft. per level |
| Casting Time | 2 rounds |
| Saving Throw | none |
| Level | mage (4th) |
The physical structure of the wall must be created upon a solid surface, or joined to existing ice, stone, earth or like support; it cannot be created hanging unsupported in the air. Horizontal forms are possible only where the ice is supported along its edges. The wall may be climbed only with spikes, picks, claws or similar means, as its surface is too slick to permit ordinary climbing. Creatures naturally adapted to ice may be allowed to climb at the DM’s discretion.
Breaking by Force
The wall cannot be less than a foot thick and no part of it can be created beyond the range of the spell. Further, its height cannot be more than 50% of the structure's width. Thus, a wall that was 30 feet high would need to be 60 feet long, which would be 1800 cubic feet at the minimum, requiring a character of no less than 13th level. One hundred cubic feet of ice weighs nearly 3 tons, so it should not be presumed that a wall of ice could be pushed over by anything short of an earthquake.
From this, we may presume that bashing through a wall of ice would require an exceptionally large creature, which would have to use a weapon or a body part — such as a horn — to keep from hurting itself. For such a creature to create a hole equalling 5 cubic feet, it would need to weigh between 2,500 and 3,000 lbs. Further, the total damage that would have to be caused to make such a hole, which might be spread over multiple hits, would be 35 damage for each 5 cubic-foot hole made.
A hole equalling 5 cubic feet is sufficient for a man-sized creature to crawl through, but not to pass upright. Larger creatures require a proportionately larger opening, while creatures smaller than man-sized may pass through with less.
Defense against Fire
| Damage (hp) | Ambient joules caused | Result against 1 ft. thickness |
|---|---|---|
| 6-8 | 6.1 million J | surface melting only |
| 9-13 | 24.6 million J | heavy melting and scarring, no clean hole |
| 14-21 | 98.3 million J | enough to burn through about 1 cub.ft. |
| 22-34 | 393 million J | enough to burn through 5 cub.ft. |
| 35-55 | 1.57 billion J | enough to burn through 20 cub.ft. |
| 56-89 | 6.29 billion J | enough to burn through 80 cub.ft. |
Depending on the attack form, magical fire may melt, scar or burn through a portion of the wall, according to the damage caused. Ordinary flame, including torches, candles, lanterns or small fires, cannot breach the wall during the spell’s duration, though such fires may wet, blacken or lightly score the surface.
Fire damage of less than 14 hit points has no structural effect upon the wall. At 14 hit points or more, the heat is sufficient to burn through the wall’s minimum thickness of one foot, creating an opening according to the amount of damage caused. The affected ice is considered destroyed, becoming water, slush and steam; surrounding ice may be cracked or weakened at the DM's discretion, but remains in place unless sufficient volume has been burned away. Magical fire affects only the portion of the wall actually struck, and does not destroy the entire wall unless its damage and area are sufficient to do so.
If breaches remove the support from a sufficient section of the wall, the unsupported portion may crack and fall, as seems fitting. Such collapse affects only the unsupported section, not the whole wall, unless the structure has been broadly undermined.
See also,
Wall of Fire
Wall of Iron
Wall of Stone
