» Fri May 13, 2011 9:29 am There was a http://www.tesnexus.com/downloads/file.php?id=5746 for Oblivion that had a great feature that allowed you to cast spells in a "sustained" fashion, instead of having to recast it every time the duration expired. It worked by causing the sustained spell to drain your mana a small amount over time until it was canceled (or until you ran out of mana). With enough mana regeneration, you could potentially have spells last more or less forever but at the cost of a slower regeneration speed compared to if you weren't sustaining the spell. This only worked for certain spells that affected the character (feather, water walking, water breathing, light, resist, shield, and all the Conjuration spells).
I think this mechanic worked well with Oblivion. It made spell casting less about baby sitting your spell timers, and more about considering the consequences of the spell effects you have active. You could have 3 spells constantly going but your regeneration would suffer, so you really had to choose what was important for what you were facing. I think it added an extra element of strategy to encounters and really helped to streamline the tedium of being a mage.
Example:
Spoiler
These numbers are just pulled out of my head, real numbers would be subject to actual spell costs.
Spell 1: Feather 100 points x 100 seconds
Spell 2: Shield 50 points x 100 seconds
Spell 3: Resist 75 points x 75 seconds
Character stats:
Mana 300
Mana regeneration: 5 per second
Time from 0 mana to full: 60 seconds
Spell 1 costs 100 mana to cast and lasts 100 seconds, to sustain it would cost 1 mana per second (MPS)
Spell 2 costs 150 mana to cast and lasts 100 seconds, to sustain it would cost 1.5 MPS
Spell 3 costs 225 mana to cast and last 75 seconds, to sustain it would cost 3 MPS
Total MPS: 5.5
Mana drained per second: .5
Time til OOM (out of mana): 600 seconds
Now having 3 spells lasting 10 minutes in itself might seem over powered, but when you take into consideration the fact that you will also be casting spells to do damage you realize you don't have that much mana.
Spell 4: 50 fire damage costs 50 mana
If you were not sustaining any spells, you could regenerate enough mana to cast this damage spell every 10 seconds. But now, you could only cast it ~6 times before you are OOM, and you have 0 regeneration. On top of this you are also losing mana, so most likely you could only attack 5 times, then you'd slowly drain out your remaining 49.5 mana. When you reach 0 mana, all your sustained spells dispel.
If you are facing melee enemies, you could lose the sustained Resist spell, improving your MPS to 2.5, if facing magical enemies your MPS would improve to 1, and if you don't need feather, that's an extra 1 MPS regardless of who you fight. You wouldn't go into a fight having every possible spell sustained on you, because it would gimp your spell casting ability. You pick and choose what works best for the encounter and decide the pros and cons of the benefits of your sustained spells versus the cons of decreased mana regeneration.
Added benefits: Instead of having to recast that feather spell every 1:40 minutes, you could sustain it for an infinite amount of time, only taking a slight mana regen loss. Same effect could be achieved with water walking, water breathing, and light spells. Bound weapon/armor spells could achieve the same effect as well.
These numbers are just pulled out of my head, real numbers would be subject to actual spell costs.
Spell 1: Feather 100 points x 100 seconds
Spell 2: Shield 50 points x 100 seconds
Spell 3: Resist 75 points x 75 seconds
Character stats:
Mana 300
Mana regeneration: 5 per second
Time from 0 mana to full: 60 seconds
Spell 1 costs 100 mana to cast and lasts 100 seconds, to sustain it would cost 1 mana per second (MPS)
Spell 2 costs 150 mana to cast and lasts 100 seconds, to sustain it would cost 1.5 MPS
Spell 3 costs 225 mana to cast and last 75 seconds, to sustain it would cost 3 MPS
Total MPS: 5.5
Mana drained per second: .5
Time til OOM (out of mana): 600 seconds
Now having 3 spells lasting 10 minutes in itself might seem over powered, but when you take into consideration the fact that you will also be casting spells to do damage you realize you don't have that much mana.
Spell 4: 50 fire damage costs 50 mana
If you were not sustaining any spells, you could regenerate enough mana to cast this damage spell every 10 seconds. But now, you could only cast it ~6 times before you are OOM, and you have 0 regeneration. On top of this you are also losing mana, so most likely you could only attack 5 times, then you'd slowly drain out your remaining 49.5 mana. When you reach 0 mana, all your sustained spells dispel.
If you are facing melee enemies, you could lose the sustained Resist spell, improving your MPS to 2.5, if facing magical enemies your MPS would improve to 1, and if you don't need feather, that's an extra 1 MPS regardless of who you fight. You wouldn't go into a fight having every possible spell sustained on you, because it would gimp your spell casting ability. You pick and choose what works best for the encounter and decide the pros and cons of the benefits of your sustained spells versus the cons of decreased mana regeneration.
Added benefits: Instead of having to recast that feather spell every 1:40 minutes, you could sustain it for an infinite amount of time, only taking a slight mana regen loss. Same effect could be achieved with water walking, water breathing, and light spells. Bound weapon/armor spells could achieve the same effect as well.
I would really love to see a feature like this implemented into Skyrim, if at all possible. Thoughts?
, they would run out fast unless you invested in some magicka and magic skills while leveling. 
