Briartangle

A briartangle spell causes living shrubbery or undergrowth of any type to be instantly changed to densely tangled briars of the thorniest sort, growing to 6 feet in height and increasing in horizontal volume to a radius of 10 feet plus 10 additional feet radius for every two levels of experience of the caster (thus, a 7th-level priest would cause a briartangle of 40-foot radius).

Beings can force their way through the briartangle readily, but the briars snag and halt missiles, thrown objects, or flying creatures within their confines. All creatures trapped within a briartangle when it forms—or those that enter it thereafter—suffer 1d4+2 points of piercing and scratching damage per round (or portion thereof) that they remain moving and in contact with the spell. Beings clad in banded, scale, or plate mail have all damage reduced to Id3 points per round. This reduced damage also applies to creatures made of rock or with skin of comparable hardness, but creatures with lesser armor, such as chain, take full damage, even if a shield is carried. Beings who do not move at all after the first round take only the damage from the first round of contact. In all cases, a successful saving throw vs. spell results in half damage (round up).

Spellcasting requiring a somatic component is impossible within a briartangle. Cloth raiment and exposed cloth, paper, or vellum items must save vs. acid once per round (or portion thereof) that they are within the briartangles confines and their user or owner is moving or they are rent and torn. This means that such items must make at least one item saving throw (for the initial round of contact). Magical items receive a +2 bonus to this saving throw. A briartangle vanishes instantly if the caster so wills, but otherwise exists until the spell expires or is dispelled. When the briartangle ends, the plants it grew from (the living material components) revert to their former state.

Fire destroys a briartangle in a round (regardless of the size of its area of effect), but creatures within it take 2d6 points of fire damage and receive no saving throw against this damage. The area where a briartangle was cast radiates a faint dweomer for 1d4+2 turns after the spell has expired, and this aftereffect can be used to confuse creatures who are following a pass without trace trail by detecting that spell's dweomer.

In addition to living plants of any type, which are transformed into the briartangle, required material components are mistletoe, a thorn from any plant, and a bud, petal, or leaf from a briar (wild rose).