Knock

This spell can undo a single means of securing a door, chest, or shackle. It negates hold portal, dispelling it; a wizard lock spell is deactivated for 1 turn but is not dispelled. A lock can be opened, a stuck door forced, a door barred or bolted can be unbarred or unbolted. These effects do not automatically restore themselves, except for the wizard lock. Knock cannot raise a portcullis or open any other portal which requires a mechanism to open (such as a winch for example). Each casting undoes a single method of securing the door or item, so that for example a door which is both locked and stuck can be unlocked but will still be stuck; a second casting of knock will open such a door.