Knock

The knock spell opens stuck, barred, locked, held, or wizard-locked doors. It opens secret doors, as well as locked or trick-opening boxes or chests. It also loosens welds, shackles, or chains. If used to open a wizard-locked door, the spell does not remove the former spell, but simply suspends its functioning for one turn. In all other cases, it permanently opens locks or welds — although the former could be closed and locked again later. It does not raise barred gates or similar impediments (such as a portcullis), nor does it affect ropes, vines, and the like. Note that the effect is limited by the area; a 3rd-level wizard can knock a door of 30 square feet or less (e.g., a standard 4' x 7' door). Each spell can undo up to two means of preventing egress through a portal. Thus if a door is locked, barred, and held, or triple locked, opening it requires two knock spells. In all cases, the location of the door or item must be known — the spell cannot be used against a wall in hopes of discovering a secret door.

Reverse: Lock

The reverse spell, Lock, closes and locks a door or similar closure, provided there is a physical mechanism. It does not create a weld, but it locks physically operated locking mechanisms, set bars, and so on, up to two functions. It cannot affect a portcullis.

Reversible

School: Alteration
Level: 2
Rarity: Common

Range: 60 yards
Component: V
Duration: Special
Casting Time: 1
Area of Effect: 10 square feet/level
Saving Throw: None