I have a little question about magic. If a spell says: Burden 15pts for 10 secs. Does that mean that my enemy will have added 15 to his inventory every second for 10 seconds, which means, after 9 seconds he will have 135 added?
Shouldn't that be enough to make most creatures encumbered? I've got a spell like that, but nothing happens when I touch people with it, is it too weak to do any real difference?

It is as I descriped with all spells and potions, right? I mean, if I put a damage health 11 pts for 15 secs on my blade, after 15 seconds my opponent will have 165 hitpoints less?

No, it means they get 15 points of weight added and the effect lasts for 10 seconds. At every moment during those 10 seconds their encumerance will be 15 points higher than normal.

Damage works the way you described, but just about everything else doesn't. Absorb Health, Absorb Fatigue, and Absorb Magicka effects also work the same way as damage, but that's it.

And health and magica potions, I guess.

Thanks for the info, Dragatus.

Yes, all kinds of restore spells are also cumulative over time. Forgot about those, thanks for pointing it out.

Burden isn't that useful, most creatures have very little in their inventory so it would take a very powerful burden spell to make anything encumbered.

It's better to use a paralyze spell if you want to stop an enemy.

Yeah, have just read that. Didn't know about the Oblivion wiki site, that site answers almost all questions gameplay related.
But thanks for your answer, anyway.

Alchemy is another nice way. If you damage Strength and Damage Fatigue you can get essentially a very long term paralyze, though the effect is not instant.

I use Burden in either spell form or as an applied poison, and only use it against heavily armored enemies. Like marauders. Get a strong enough potion going, and watch that dude stick to the floor.