This doorknob looks like a normal doorknob. However, an adventuring party may find an awful surprise upon attempting to grab this “normal” doorknob as it moves to the opposite end of the door.
This doorknob is made of a very hard material, and is enchanted with anti-magic properties. It has also been ritually created to prevent unauthorized creatures from passing. Attuned and fixed to a specific door, it guards the door with fervor. Should an unauthorized creature attempt to pass through, the doorknob maneuvers itself away from prying hands. It can parry weapons, intercept projectiles, and absorb magic. If a creature manages to grab it, the doorknob will move wildly in an attempt to free itself, preventing with all of its magical might from being turned and its warded door from being opened.
The doorknob will behave itself, however, upon the utterance of a password. Upon uttering, the doorknob will move back to its proper position, and allow its warded door to be opened properly. Once the door is closed again, the doorknob resets.