3e SRD:Abjuration School
From D&D Wiki
|This material is published under the OGL|
Abjurations are protective spells. They create physical or magical barriers, negate magical or physical abilities, harm trespassers, or even banish the subject to another plane of existence.
If more than one abjuration spell is active within 10 feet of another for 24 hours or more, the magical fields interfere with each other and create barely visible energy fluctuations. The DC to find such spells with the Search skill drops by 4.
If an abjuration creates a barrier that keeps certain types of creatures at bay, the barrier cannot be used to push away those creatures. If the character forces the barrier against such a creature, the character feels a discernible pressure against the barrier. If the character continues to apply pressure, the character breaks the spell.