So, I think I've figured out a good way to prevent players from cheesing multiple souls out of the same kill with multiple soul trap effects. All of the enchantments in the game with the soul trap effect have had a 100-point dispel effect added as the primary, which should serve the purpose of removing any previous soul trap effect that was on there before.

Now, all I have to do is set the duration of the soul trap effect as short as possible so that you can't just go back afterward and cast a soul trap spell, then kill the target with both effects active. My question is how low can I set the duration for the soul trap effect to actually work if you kill the target with the weapon bearing said enchantment?

I think 2-3 seconds is the lowest duration for a "Cast on strike" spell effect.

So, 3 seconds should be plenty, then.

I can't imagine there is a hard-coded minimum, you could probably set it at 0, but minus numbers would probably cause a crash. It would be an interesting experiment though, I might have to try that.

I've used this duration for my self.

You might need to add 1-2 seconds more when you have an enchanted ring with a "Cast on target" effect if the ring is used from a greater distance.
Also consider any spell effect that has like this:

"Soul Trap for 20 seconds" & "Fire damage 2 to 10 pts for 20 seconds" - cast on strike and perhaps add 1-2 second to that enchantment

Actually, what I've done is added a 1-second, 25-point drain health effect to the Amulet of Gem-Feeding, instead. That way, you can deal the killing blow with it (and thus use its 2-second soul trap effect to grab the soul), else it doesn't do anything.

Except cast dispel. It sort of does that, too.

Well that's interesting I didn't know you could get multiple souls from the same creature just by adding multiple different named soul traps... not something that would have been an issue before. Interesting engine glitch. Who's going to think of that off hand anyway as it would maybe have been thought of by a dev but I guess not.

Well, I'm going to try making all of the soul trap effects instant and see how that works. I'll test it when I'm done with everything else, unless someone beats me to the punch and posts the results here.

Hey, you'll even get credit in my readme and everything. Think of the prestige!

Well not to do one ups man ship.. but its 1 sec is all that's needed just like oblivion. As long as the weapon or spell you have the 1 sec soul trap effect attached is what kills the creature you'll soul trap it.

In oblivion I have this on a ebony dagger called "Ebony Dagger of Souls" 1 sec soul trap, 5 fire dmg, 5 frost dmg, 5 shock dmg. That way I also can cause elemental damage to anything unless its immune to all.

Well, many thanks.

*Credit*

Actually, I think it is around 2 seconds. I recall being frustrated because I could never catch anything in Morrowind because the spell effect didn't last long enough even during killing blows for a 1 sec on strike. I pushed it up to two seconds after a while and haven't had a problem with it since.

Well I typed the 1 sec thing because I tested it, it does work for me at least. If say there were other effects that lasted longer then 1 second causing damage to it then yes it wouldn't get soul trapped (soul trap running out of time). I made a ebony longsword with same effect settings as the dagger I mentioned I had 3 empty grand soul gems went killing goblin in mournhold and pop for every killing blow soul gems got filled 3 goblins 3 filled gems.

Hmm... looks like I'm not going to be able to get out of testing them, after all.

As a latter side note while it may seem obvious to me this is also assuming the enchanted weapon doesn't run out of charges before you kill the monster.... If the enchanted weapon with 1 sec soul trap runs out of charges before landing the killing blow it will not get soul trapped. This is why a 2 sec soul trap may sometimes be better for some depending, like if your enchanting skill is low and doesn't recharge as fast.

May seem silly to quote myself but I don't feel like retyping.