Trying to understand weakness to magicka

[Armadax]

I was thinking about starting a High Elf with the sign that gives 100% weakness to magicka for the absolute most + mana you can get WITHOUT going atronoch sign.

 

As ive understood it the weakness to magicka dont affect elemental damage but magnitudes on spells.

 

So a 10 fire damage over 3 seconds spell cast on you will become 10 fire damage over 6 seconds. Correct?

 

The thing is ... will this work on beneficial spells aswell?

 

Meaning: Heal 10 points for 3 seconds will become heal 10 points for 6 seconds?

 

or: Invisibility on self for 10 seconds become invisibility for 20 seconds?

 

Any high elfs with the weakness to magicka sign here that could tell me if its possible to play a pure mage like this without getting 1 shotted by mages? The plan is to go items and enchantments with Spell reflection and spell absorption, the trick is to survive that far ;)

[forli]

I think that weakness, resistances, absorption and reflection only work with hostile spells. So "100% Weakness to magicka" is only a negative effect. You take double damage / penalties from enemy spells, but not double cure / boost.

[Pronam]

Exactly, read more about it here: UESP, Weakness to Magic