Effects with a duration of 1s are not instant when cast by items
Effects with a duration of 1s only actually last over 1s in Morrowind if you cast them. But if you use an enchanted item, effects with 1s duration are instant.
I've tested this with the following effects:
- Damage Health: 100 for 1s on stike on a weapon, you can see an enemy's HP bar losing chunks instantly vs. slowly decreasing over time
- Restore Health/Fatigue: You can heal as fast as you can click vs. being limited by the strength of the effect over 1s
- Summon: A creature only pops up for what looks like a single frame in Morrowind vs. staying for a second
Furthermore, Morrowind doesn't have 1s durations on tooltips and only uses duration if it's 2s or more. For example, "10 Fire Damage for 1s on Target" in OpenMW is just "10 Fire Damage on Target" in Morrowind. This is true for both spells and items, which is technically only correct for items as casted spells do have durations of 1s in Morrowind despite not showing. So I'd suggest to change the tooltips to remove 1s duration on items but not on spells to accurately report what actually happens rather just copying Morrowind's incorrect tooltip on spells.
Found that Engraved Ring of Healing, Nuccius's Cursed Ring and Eleidon's Ward all have non-instant effects. Perhaps it's only instant on self made items?
Robe of the Lich has an instant effect. Maybe drain/fortify effects are exceptions due to the way they work with duration.