Dome of Flaming Death

An invisible web of Fire magic is created over the entire province where this spell is cast. Any spells cast into the protected province will trigger the deadly trap. A powerful blast of fire will find its way to the casting mage and burn him and possibly also the laboratory to cinders. The more magic gems put into the spell, the longer the dome lasts. If the mage who cast the dome dies, the dome dissolves instantly. The dome does not stop spells that pass through it, but it may stop the offending mage from ever casting spells again.

Text: Illwinter Game Design, via Dom6 Inspector