How about a spell for DnD Next?
Circle of Spell Protection
2nd-level Adjuration
Casting time: 1 minute
Range: Circle five feat in diamiter
Components: V,S,M-chalk, dust, unholy/holy water, or blood
Duration: Concentration, up to 1 day
Until the spell ends, for any spell that enters or exit the circle, the spell caster must make a saving throw using the ability used by the spell caster to cast spells (eg. a wisdom saving throw for a cleric, intelligence for a wizard) with a DC equal to the spell casting DC + 3 for the creator of the circle. If the caster succeeds, the spell may enter the circle. If the caster fails, the spell is cast, but does not enter the circle, and all creatures in the circle are immune to any of the spells effects.
Thoughts?