Level: Bard 2, Sorcerer 2, Wizard 2
Components: V, S, F
Casting Time: 1 standard action
Range: Close (25 ft. + 5 ft./2 levels)
Area: 20-ft.-radius emanation centered on a point in space
Saving Throw: None
Spell Resistance: No
Uttering a low chant, you ring a crystal bell with the drumming of your fingernails, bringing into being an invisible warded area.
Greater alarm sounds a mental or audible alarm each time a creature of Tiny or larger size enters the warded area or touches it. A creature that speaks the password (determined by you at the time of casting) does not set off the greater alarm. You decide at the time of casting whether the greater alarm will be mental or audible.
Mental Alarm: A mental greater alarm alerts you (and only you) so long as you remain within 1 mile of the warded area. You note a single mental “ping” that awakens you from normal sleep but does not otherwise disturb concentration. A silence spell has no effect on a mental alarm.
Audible Alarm: An audible greater alarm produces the sound of a hand bell, and anyone within 60 feet of the warded area can hear it clearly. Reduce the distance by 10 feet for each interposing closed door and by 20 feet for each substantial interposing wall. In quiet conditions, the ringing can be heard faintly as far as 180 feet away. The sound lasts for 1 round. Creatures within a silence spell cannot hear the ringing.
This spell works on creatures traveling through the area on coterminous or coexistent planes, such the Ethereal Plane and the Plane of Shadow.
Greater alarm can be made permanent with a permanency spell cast by a 10th-level caster at a cost of 1,000 XP.
Focus: A bell made of carved crystal, worth at least 100 gp.
Source: Spell Compendium, page 8.