Watchware

Watchware was an arcane evocation spell that placed a mental alarm on an inanimate object. A later version of this spell fell under the school of abjuration.

Effects
In order to cast this spell, the caster had to touch the object being alarmed. The object could be almost anything as long as it was nonliving, inanimate, and motionless, because movement was one of the conditions that would trigger the alarm. Other triggers included being touched by something or someone substantial (a speck of dust was apparently not enough), being tread upon by a creature, being moved by natural forces (wind, flood, earthquake, etc.), or being the target of dispel magic.

The alarm came to the caster in the form of a silent mental image of the object and all its surroundings out to a radius of 10 ft (3.1 m). The alarm lasted for one minute and impinged upon the mind of the caster whether he or she was awake, asleep, or unconscious. The mental image disrupted the caster's concentration, so any spell being cast at the time of the alarm fizzled. The caster's mind had to be active to receive the alarm: being turned to stone or placed in temporal stasis prevented the perception of the mental image.

Watchware lasted until triggered and the target object gave off a faint magical aura while the spell was active. The caster was limited to a number of watchwares equal to his or her level, but practical consideration of possible accidental triggering often kept the number of active watchwares very small.

Components
In addition to a verbal component, the somatic component included touching the object being alarmed, and the material components were a spiderweb, a shard of glass, and a small silver or brass bell. A different version of this spell required a mix of rare sands and powder that was worth at least 500 gp.

History
This spell was published in "Volo's Guide to All Things Magical" and became generally known to the magical community.