Originally used by the winter witches on the field of battle in the early days of Irrisen, _blast barrier_ has entered the oral traditions of many northern barbarian tribes as legends of winter witches possessing powers to bend the very ground of a battlefield to their will. _Blast barrier_, however, has proven to be an exceptionally versatile spell as far as terrains are concerned, for it works equally well in swamps, deserts, or any region where the ground is soft or easy to shape. When you cast _blast barrier_, you cause a rippling wall of loose earth, mud, snow, sand, or gravel to spring up in a designated space within the spell’s range. This wall provides total cover to all Large or smaller creatures and objects. The barrier can only spring up in an area of natural, unworked ground. The energy that forms the wall’s matrix is unstable, and you must concentrate to maintain the wall’s shape. A _blast barrier_ has an AC of 9, hardness 0, and 5 hit points per caster level. When a _blast barrier_ reaches 0 hit points, or when you cease concentrating on maintaining it, the energies that maintain the barrier’s shape fail with explosive results, sending sharp chunks of the materials comprising the wall and magical energy out along both sides. Any creature that is adjacent to a _blast barrier_ when it explodes takes 2d6 points of slashing damage and 1d6 points of sonic damage per 3 caster levels (maximum 6d6). A successful Reflex save halves the total damage done. Spell resistance applies as well. This instability can make using a _blast barrier_ risky, but many of the spellcasters that pioneered the spell became experts at its tactical applications, often using the barriers to cover an escape while lobbing spells and parting shots, hoping to trigger the barrier’s destruction just as their would-be pursuers approached.