Secure Seal

4th-level abjuration

Casting Time: 1 minute
Range: 30 feet
Components: V, S, M (gold dust worth 100 gp)
Duration: Until dispelled
Classes: sorcerer, wizard

This spell affects a portal or opening within your stronghold as arcane lock, but it additionally creates a magical trap on it. If the secure seal is forced open by any means, it explodes in a 20-foot radius burst, dealing 5d6 force damage. This burst does not harm the walls, floor, windows, or any other permanent furnishings or features of your stronghold. Spell resistance applies against this damage, A Dexterity saving throw is allowed for half damage. The secure seal can be detected as a magical trap. After a secure seal explodes, the spell ends.

You can freely pass through your own secure seal without triggering its explosion.

You can cast this spell outside your stronghold, but its duration is reduced to 1 day.