Sometimes, a mage doesn't want anyone to go through a specific door or loot a chest. Magic Lock magically locks them, and only the Unlock Magic spell can break the enchantment.
|| The magical locking of doors works in nearly every situation. Even normal locks can be transformed into magical locks by means of this spell. Thus the very creature who initially locked a door with its own key may be forbidden access. Mix ash and moss, gathered from darkest glens under heavy clouds, into a strong garlic paste. While mixing, sing a melody that no other creature has every heard. For greatest security, the melody should be different each mixing; so each magical lock will require a subtly different magical key, and anyone trying to break the magical lock will not be able to use any previously discovered keys.|
- In Ultima VI, if the Avatar uses Magic Lock on a already locked door, and then casts Unlock Magic, all locks, even the natural ones, are removed and the door can be opened.