I'm level 30 and last night I did the Azura star quest. I play on Expert.

Those Necromancers kicked my behind into Oblivion. Well not the Adept or Apprentice ones, but that MASTER Necromancer just would not bloody die. 6 hits of Thunderbolt and 1/5 of her health gone, and she heals.

Ugh. I tried every combination of cheap techniques I could think of (stone fish/fast healing + call of valor + storm atronach) but she just killed them and then killed me. Not to mention resurrecting all the dead adept mages with invincibility. So I just got sick of it after a while and loweredd my difficulty to Novice for the remainder of the battle.

I'm fairly sure this was the first 'Master' fight I've had to do (asides Dragurs and a Master FIre mage) and it was ridiculous.

What am I doing wrong? I've always focused on Destruction and all magic signs. I have high alteration and destruction.

Even with Morokei, Arch mages robes, ring of magicka, necklace of magic resistance, my magicka still regnerates very slowly in battle. This isn't usually an issue though unless I'm trying to spam thunderbolt a master necromancer.

I don't use exploits at all, so none of that Alchemy/Enchantment stuff. Maybe I should start wearing Armour? But then my Magicka regen would be even lower....

Illusion > destruction. Use Perk Calculator to show us your build. Have you got any sneak? I remember I breezed through Azura's Star level with sneak and the Shadow Stone.

I have 93 Destruction, 76 Alteration, 58 Illusion.

I know a lot of people do that sneaking up then backstab thing, but I haven't even looked into those perks yet. I have very high sneak though just from sneaking in general. Maybe I should start that.

I don't understand that Caclulator, I put in all my perks, now what?

Save it and then copy the link it gives you. Sneak is kind of cheese, too. You can literally kill someone sitting at a table in an inn and his drinking buddy beside him won't notice.

I have found that getting up close and personal with a high level Shield spell from Alteration and a fully perked Lightning Cloak can be very helpful against other Mages. This does not do well against armed opponents, but Mages do not react well to being cornered and slowly turned into ashpiles that can not be turned into thralls/summons.
If you have a staff that is nasty, use it intead of your own spells. Saving your Magicka is critical in this game if you do not want to use Enchanting to reduce spell costs, playing a Mage without using exploits is a real challenge in this game at higher levels.

Maybe ditch the archmage robes and go for a set od enchanted armor. Get 2 magicka boosts that way, and at least one magicka regen boost, and one or two resists maybe. With dual enchants that is. Even without gotta be better than the robes.

Also can get destruction cost to zero, which is nice.

The problem is that enemy spells scale like crazy whereas ours don't. I was in Sunderstone Gorge earlier and was getting 100 HP lopped off per fireball, despite having 65% magic resistance. Look at enemy mages like Malkoran, Haldyn, or Sebastian Lort to see what destruction magic is capable of doing. Malkoran one-shot me with ice storm on adept difficulty one time. I have to dual-cast it 4-5 times to kill a cave bear.

ETA: You need either magic resistance, help, or both. I usually pick the Lord Stone for the 25% magic resist. Having a follower and/or summons helps immensely as well.

destruction spell really isnt designed for anything higher than normal difficulty. i would really hate to tell you just lower the difficulty but ultimately, the fix will be trying to patch your defenses or resorting to a secondary method of damage rather than somehow boost destructions relatively miserable damage output.

Enemy spells scale? I knew ours don't, but theirs do? That reeks of injustice.

their spells dont technically scale, the damage itself is multiplied (2.0 at master) while your damage is halved at master.

A 100 damage lightning bolt will do 50 to enemies, often time just 37.5 if they have 25% magic resistance while you will take 200 damage(!) from the same spell. NPCs also tend to have altered spells that usually cost very little magicka and do much more damage than the dragonborn's version.

Completely forgot about difficulty level factoring into damage done and damage received.

Those mages can be difficult to beat sometimes. I suggest one hand a destruction spell and the other hand fast healing.

Ugh... that inconsistent regeneration really ticks me off. >_>
I think that magicka is not only one who suffers that, but stamina and health also.
I really don't know why did they decide to go with it since it ruins the immersion greatly (it's simply too illogical and makes no sense even for a fantasy game) and is irritating as hell.
I really hope that they do something about it.

I respectfully disagree with you unless someone can present proof to the contrary. Either their spells scale or they have access to much more powerful versions of the same spell.

I have a character who is at the magic resistance cap with over 700 HP. I fought Krosis, whose main form of offense is his Staff of Fireballs (damage is stated in the item description), and he basically couldn't hurt me. I was at Silent Moons Camp shortly thereafter, and a Bandit Mage, a BANDIT (!) was knocking all kinds of health off of my bar with the very same fireballs, except he was casting them, not a staff. Malkoran is a perfect example of why I disagree. He has one shot me a few times with different characters. Also, there are various spell traps that do devastating damage, like the one at Lost Tongue Overlook.

Edit: BTW, most of my experiences have been on Adept, so the damage modifiers are not an issue.

To solve the problem of boss level enemy mages, my mage character carries a mace (this one absorbs magicka) and a shield (Shield of Solitude now). I know better than to try to out spell them, so I buff myself and follower (if I have one), conjure something, then I get in their face and beat them with mace and shield. It works very well. I like how they appear to panic and try to get away. I attack their weakness and hide mine.

I did mention npcs having stronger versions of spells. If you're curious, open the console and hit psb to gain access to even the enemy spells and test them. however, i am fairly sure enemy spells do not actually scale with their level unless their using a completely different version of the same spell.

Potentially: adept necromancers can cast a 60 damage fireball while master necromancers can cast a 120 damage fireball but it inst because the spell damage scaled with level, its just because their using an entirely different spell.

all of this will be affected by difficulty rating.

That's the best way to attack mages. Their resistance to getting thumped in the head with a hunk of metal isn't very good. The other way to outshoot them with a bow. I've beaten quite a few that way.

Magic regen during combat is not something to be shooting for, The base multiplier on the value is so low that no amount of addition percent fortifications will yield a decent number. Focus on cost reducers or magica pool increasers, or if you want regen- realize you are going to see the effect only when out of combat.

I had a destruction mage with the same trouble. She was fine until meeting a boss mage. I don't recall the name or place, but I got fried six or seven times before losing it and just charging in with my unskilled mace and whaling away. Of course he fell and I'm screaming WTF.