D&Dtools1

When you speak the triggering phrase, six puffs of shadow burst forth from your location, flying out to cover the six areas you target in your mind.

You create four cylinders of magical darkness within the area, which randomly and rapidly move around at ground level, giving concealment to nearby creatures. The cylinders of shadow (called "glooms") occupy space as Medium creatures (a 5-foot square), are 10 feet tall, and cannot leave the area of the spell.

A creature fully engulfed by one or more of these glooms has concealment. This concealment applies to attacks made against or by creatures in these glooms.

The glooms are under your limited control. While the spell is in effect, you can use a free action on your turn to direct a controlled gloom to attach itself to and envelop a particular target and follow it. The target can attempt a Will saving throw to avoid being enveloped. Success indicates the gloom dissipates; failure means the target is surrounded by magical darkness. Once it is attached to a target, a gloom stays with that target until the spell's duration expires.

Origin: This spell was created centuries ago by a steel dragon who eschewed human contact and masqueraded as a cruel necromancer who dwelt in an isolated tower.