Arcane Seal

This spell can be cast upon a doorway or lock. It magically seals the target, and attaches a mystical alarm to this location. The caster may choose a passphrase to bypass the seal, any creature that speaks this passphrase may pass through the seal. Otherwise, a door or object secured with this spell can only be opened with a successful dispel magic or knock spell, or with a DC25 Strength check. In addition, if the door is opened in any manner, the caster receives a mental alert: the passphrase, set when the spell is cast.

A knock spell suppresses the seal for 10 minutes. Dispel magic permanently destroys the seal if the dispel check is successful. However, the seal sends its mental alert even if its magic is dispelled.

At Higher Levels. When you cast this spell using a spell slot of 3rd or higher, the DC for dispel magic is increased by 5 for each level above 3rd.