Sleep field
Using this spell creates a magical sleep field that will cause everyone that comes too close to it to fall asleep. However, its use is rather limited. If not cast on a narrow path, the caster's foes can simply walk around it, making the creation of the field rather pointless. Also the field dispels itself after several creatures walking into it.
The spells Sleep and Mass Sleep are much better, since they directly target the foes.
Lore[]
Least damaging of the three energy field spells, In Zu Grav is often the most effective. The spell cloaks a foe in purple haze that puts it instantly to sleep, taking it out of the fight, rendering it helpless. Like the other two similar spells, In Zu Grav can affect friends as easily as enemies. While sleep will not directly harm friends, falling asleep on the field of battle can be deadly. In Zu Grav is easily mixed of common ginseng, spider silk and black pearl. For best results, add the air of many yawns and sand from sleepy eyes.
- from Book of Lore (Ultima V)