The character produces acid from the hands or mouth (caster's choice, but once chosen, the source of acid cannot be changed). The acid does no harm to the caster but causes damage to an opponent if the caster makes a successful attack roll. The attack must take place within a number of rounds equal to the caster's level, or the acid becomes inactive.
The damage is 1d4 plus 1 hit point per level of the caster. The acid affects plants and animal flesh only, whether that material is living or dead. It does not affect metal or stone. Thus, an attack that does not cause damage to an opponent might adversely affect that opponent's clothing.
The character constantly secretes a brownish, slightly acidic liquid from the hands or drools it from the mouth. The secretion slowly dissolves any plant or animal material that it contacts (such as a cotton tabard or leather gloves). It also causes an inflammation where it touches the caster's flesh. Unless the use activates the legacy, the acid is too weak for use as an attack.