Knock

Knock was a transmutation spell that could open locked, barred, or stuck doors with only the spoken word. Clerics who had access to the greed domain could also cast this spell as a divine power.

Knock was one of the spells granted to the wearer of the commander's rings worn by the leaders of the War Wizards of Cormyr. It was also a power of a rod of displacement, which was a magical item from Myth Drannor, or of a staff of open doors or a staff of the magi.

The spell had a reverse form called lock.

Effects
This spell would instantaneously unlock or unstick a number of doors within a range of at least 100 feet, depending on the power of the spellcaster. Bars holding doors shut would be lifted, and padlocks closing an item would become unlocked. Secret doors could be unlocked as well, but they still had to be found to be passed through. Magical locks could be unlocked&mdash;unless they had been protected by the secure spell&mdash;but they would relock after ten minutes.

The spell had a number of limitations. It only affected doors, boxes, or chests or other such things that could be opened. It did not actually open the door or box; it only removed the hindrances toward doing so, so a heavy gate or portcullis might still pose a problem for the caster. The spell had no affect on ropes or vines, so a box wrapped tightly in rope still had to have the rope untied or cut to be opened. It was limited to undoing only up to two means of preventing access, so that the contents of a locked chest welded shut and wrapped in a locked chain could still not be fully accessed by a single casting alone.

One strange use of the knock spell was its ability to "unlock" the healing power of a star ruby when followed by the wraithform spell. The star ruby would then become a thick red vapor, which had powerful healing properties when inhaled.

The reverse form, lock, shut, locked and bolted a door it was cast upon.

Components
The spell simply required a verbal command.