There are three types of duration constants:
No duration per se but an effect or spell is applied instantly to the target. Most damage spells and death spells have this type of duration as well as effects which are played instantly, such as a flare of light or an explosion.
An effect that lasts between 0.0001 seconds to nearly permanent. Buff spells fall into this category and visual effects applied to objects or at locations.
An effect that lasts as long as the target is alive, valid and the effect is not dispelled or rested away.
- Durations will end automatically if the object the effect is applied to is destroyed or dies or becomes invalid.
- Durations are applied to objects using the scripting command ApplyEffectToObject() and at locations using ApplyEffectAtLocation.