Spell Draining (3.5e Equipment)
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Whenever a spell draining weapon hits a spellcaster, it leeches some of that spellcaster's power. On a successful hit, roll a d10 to determine what level of spell slot is drained away. The roll result corresponds with the level of the spell slot drained. In the case of a 10 being rolled, you drain two spell slots and roll two more d10s, ignoring any further results of 10. If the result of your roll exceeds the highest level spell slot the targeted spellcaster has, a spell slot of the highest level he can cast is drained. In the case of prepared spellcasting or multiple spellcasting progressions, determine randomly which spell is drained.
The spell draining effect can occur only once per round and only during the wielder's turn. The effect is triggered by a successful attack against a spellcaster. Creatures without spell slots do not trigger the effect, and do not count towards its usage for the round.