Purpose of Dual Casting Perk in The Elder Scrolls V: Skyrim

[Agnes!]

I thought somewhat fishy; right from the start of the game you can cast two of the same spells at the same time. It also has an obvious effect of taking enemies down quicker than just shooting from one hand. However, I didn't understand how the dual casting perk would make this any different. I saved the game before picking it. I simply went up to it and held down my casting in anticipation that I was out of magicka and looked at how much health it has. I did this a few times just to ensure there was no room for error. I then did the test once more a few times subsequent to picking the dual casting perk. There is nothing changed other than the casting graphic. Its health ended up exactly the same when I was out of magicka as it was before ever picking up that perk. This maybe just an issue with a low level Destruction skill or the default spells just not doing enough damage that whatever hidden modifier this perk is supposed to add gets added but for now it doesn't do anything.

[Wyl]

I am not agree with you. It does do something. It makes you run out of quicker and actually does less damage overall. Maybe it's supposed to make spells cast in short bursts "stronger" but at the cost of more magicka. This totally not worth it at all on the lower levels.

[Bubboy]

Dual-casting is particularly helpful for the staggering effect (Impact perk). As far as damage, I haven't tested it. The stagger effect alone makes it worth using though. I was able to kill the guard with five casts without the perk (4 might have been enough with burn damage). With the perk, I ran out of mana after 4 casts but the guard died from burn damage. So it was actually faster without the perk.

[mbangali]

You get more damage than just casting the same spell twice, but the damage to mana ratio is lower. Dual cast works great for charge spells like fire bolt or incinerate. also it doubles the effect time for things like oilskin, summons, invisibility. Also when you have impact you can infinitely stagger enemies if you get the timing right and you have excellent mana regent. This makes 1v1 even against dragons quite easy if you keep your timing and don’t miss.

[LotusN]

The damage to mana ratio is a lot lower and the only reason it might be usefull is because of the Impact perk. You still can cast the 2 spells separately even if you have the perk, as a result of this it permits you to select what option to take, either to use more mana and stagger or just do more damage to each mana. Only thing is it uses up 2 perks points.

[AlisaDsa]

There is one more potential benefit of dual-casting spells and that is like shock rune or frost cloak. If you cast one then another, the second is cancelled and therefore dual-casting is the only way to get a stronger effect. That said, I have no idea if it actually makes a difference with those spells. Augmented shock isn't raising my shock rune damage and the game mechanics are so broken.

[Dorkfoot]

Dual casting seems to do well with summoning, due to the duration boost. Strangely, I dual casted an alteration spell which is supposed to make it stronger, but got a longer duration instead.