Oblivion Mage vs Skyrim Mage, a comparison: Your average Oblivion mage was a hell of a lot less squishy, as a fifth of their endurance would become health for free. In Skyrim, choosing health too often will give you magicka problems, and choosing magicka too often will get you two shot. It can be difficult to strike a balance.
An Oblivion Mage would usually neglect any school that wasn't Conjuration, Destruction, or Restoration as far as combat was concerned. Basically, nuking things, summoning things to nuke things, and healing yourself as necessary.
A Skyrim Mage pretty much needs to embrace a wider range of defensive options in order to preserve themselves. Huge heals no longer cut it, as it is scarily easy to die in a mere two hits rather than say 10 hits in Oblivion.
Choosing your race: I personally pick whatever race i find aesthetically pleasing. If you really want to go down the min/max route however, i recommend a High Elf or Breton. 5 levels worth of extra magicka or some extra magic resistance are very nice indeed, and their powers can easily save you from some sticky situations.
The other races really dont have an advantage over each other. Sure, they might increase/decrease your skills in some schools, but those extra 5/10 levels are the easiest to get in the entire game anyways. It means very little in the long run. Go an Orc for all i care.
Perks/Skills:From left to right, in the order they appear in the skills menu.
Illusion: This is a very important skill. Being successful as a mage in Skyrim hinges upon properly defending yourself, and the crowd control and utility this tree provides makes staying alive so much easier. I believe the reason many players are struggling adapting to Skyrim is because they neglected this crowd control and utility in Oblivion because it simply was not necessary.
I recommend everything in this tree except for quiet casting and dual-casting. In fact, i do not recommend dual casting in any school except Destruction. I have given the explanation its own section later on.
Conjuration: This is also very important, more so for the survivability it offers then the damage it deals. Getting a big meat shield to grab the attention of enemies will keep you alive and allow you to take free potshots at enemies who are largely stationary.
I recommend getting Summoner and its subsequent perks, as well as the half-magicka no-brainer perks. You can take Necromancer and its subsequent perks instead, but corpses to reanimate aren't always available, and i prefer the consistency of the summons. As for the bound weapons perks, that kind of blurs the line between pure-mage and something else entirely doesn't it?
Destruction: Needs no introduction, your bread and butter. You actually want Dual-Casting and Impact here, the extra cc effect and burst damage is sometimes just what you need. The cc can easily be chained mutiple times to keep an enemy constantly reeling for as long as your mana will allow. The perk for Runes i find is highly situational and not all that useful mostly.
The real choice is Augmented Fire/Frost/Shock. Fire will give you a little extra oomph in terms of damage. Frost allows you to escape melee attackers more, and Shock offers more of an anti-mage feel to your character. Also very few enemies resist your spells, such as Ice Wraiths, corresponding Atronachs and most likely the Daedra. I personally chose Frost, as i feel i cannot get enough survivability.
If you're having a really hard time deciding, just pick whatever animation you think looks coolest.
Restoration: This is where my guide might make you flip. [censored] Restoration. This school is very misleading. Although its solely focused on protecting you, it does a horrible job of doing so. An Apprentice Restoration spell can recover half of your life, and an Adept one can probably recover the entire thing. You're squishy, your health pool is tiny, you have no need for big heals. Healing your entire life bar doesn't mean [censored] if your entire life bar consists of two melee swings. Get me?
Go as far as Apprentice. Get Recovery when you can, and maybe Regeneration too, but that's it. If you really want to push it, go for Adept. It is only one extra skill point, and a full heal can be nice in a very few situations.
"But Rockpops, its not just about big heals" I hear you moan "What about wards and CCing Undead?". First of all, wards were poorly implemented, they have far too much risk and far too little payoff. You risk getting CCed yourself if the spell is too powerful or you ward too late, and believe me, a quick knockback animation can mean death when you're this squishy. You also risk losing a lot of mana if you use it too early. On top of that, you need to observe the behavior of enemy casters in order to effectively use it, which, lets face it, isn't always going to be a reasonable thing to expect of yourself. You are not super perceptive, super cat-like reflexes guy, be realistic.
In summary, almost every possible situation where you might think you need a ward, a summon to tank your damage will do just as well. A summon doesn't have the risks involved either. Ive had clutch dual cast destruction knockbacks save my life way more often than a ward ever will.
Lastly, CC for Undead. The one decent argument for taking more points in Restoration. You can CC them for a few levels once you get the Apprentice rank...and then you can CC them again with Illusion once you progress that far.
The gap in between is pretty large. But is it really worth it to invest so many points just so you can cc a specific type of enemy from level X to level Y? The payoff for not bothering with more Restoration will be worth it, i assure you.
Alteration: Alteration is your last line of defense. The enemy for whatever reason, has avoided CC and ignored/killed your summoned creature. damage is inevitable. Alteration brings you some durability. Not enough to run around and neglect Illusion and Conjuration and generally be a [censored] idiot, but some. It also brings yet another CC effect (paralyze) and some nice utility and flavour spells too (Detect Life, Clairvoyance).
Get everything in this tree except dual-casting. Stability is a bit iffy. Fights going over 45 seconds (the duration of the flesh spells) is certainly not unheard of when you need to be super careful not to get bursted in seconds. 60% less damage from spells is so damm overpowered i dont even know what to say.
Note: Rumor has it that Mage Armour is functioning incorrectly and does not grant bonus armour. It may very well be [censored], but i thought i should let you know. Rockpops is not responsible for any and all dismemberment involving the use of skin spells.
Put the perks you dont spend in Enchanting or Alchemy or something. Whatever floats your boat.
Shouts: I dont have the encyclopedic knowledge of shouts neccessary to tell you which is best. This is just a reminder not to neglect them. Many shouts are nice cc effects or can be used as escape abilities that can save your life. Be creative.
Combat: You need to know when to play it safe or just outright burst an opponent. Against less numerous/powerful opponents, or opponents that are susceptible to burst, just cast one dual-casted Destruction spell after the other. They will be chain CCed by this. You are basically gambling that their health will run out before your mana does.
Missing a spell can be critical. If you throw everything you have at something and its still at half health, you are doing it wrong. You will die because you have no mana to defend yourself with. I believe the people that believe that pure-mages are unviable are attempting to do this in every fight. It doesn't work like that.
When enemies are more numerous/powerful and or less susceptible to burst, you need to do this instead. I usually start by casting my skin spell as well as a summon of choice simultaneously. I use whatever means necessary to establish enemy aggression on my summon. This can be anything from a Shout to a Illusion spell. At some point between establishing aggression on my summon or when the aggression is already there, i calm/fear enemies so that we only need to fight one person if they're multiple enemies.
Now comes the hardest part. Basically what you need to do i gradually wear your opponents down. Take a few potshots with Destruction spells to an extent where you can still afford the mana for additional summons/cc/skins/healing. Vitality before violence.
When you think they're worn down enough, feel free to let loose with a chain of Destruction spells to finish them off. This is how fights can easily last a long time. It can take a very long time to wear down an enemy to the point where it is safe to recklessly throw your mana at a target. Getting a feel for assorted mana costs, the duration of cc, the durability of your summons, the damage of your spells is the real challenge.
Y U NO DUALCAST?!: Double the effectiveness, double the cost, whats wrong with it exactly? The problem is what the description means by "effectiveness". A dual casted spell usually doubles in duration, not in potency. This will not give you double Atronachs or double armour rating from Stoneskin. The only spells that come to mind that actually increase in potency are damage spells healing spells and ward spells. Wards svck, heals give you your entire life bar regardless by casting two separate heals at once even though its not technically "dual-casting". Destruction also has the added bonus of a cc effect to go with a dual-casted spell. Duration increases are especially irrelevant on summons, who more often than not die before they actually "time out".
What about Illusion and Alteration? Think of dual-casting these as a HUGE early battle disadvantage for a minimal late battle advantage. You are heavily investing mana into one of three areas (summons/cc/skins) and leaving little for the other two, as well as any you may use for actually dealing damage. If you dual-cast stoneskin against an opponent you could of just bursted with your full mana bar, I'm going to call you an idiot. If you dual-cast stoneskin and it doesn't leave you enough mana to use summons or cc to stay alive and you die before even half of the duration of that Stoneskin, I'm going to call you an idiot.
Dual-casting that will only let you reap any sort of benefit if you last the entire double duration. That way, you didnt have to waste two casting animations. THAT IS IT! That is the only minuscule bonus you could possibly get from dualcasting. If dualcasting increased the potency as well as the duration, maybe i would consider it.
The End: It is my hope that i have effectively dispelled any doubts anybody has about the viability of pure-mage characters. I also hope that i have helped ease the transitioning process from playing a Mage in Oblivion and playing a Mage in Skyrim. The game has only been out for a few days, everything is very very new. I think these complaints of Mage unviability are born of ignorance more than anything else. I know the fact that i neglect Restoration and dual-casting feels very counter-intuitive, but im more than willing to listen to any arguments you have for them. In fact, i encourage you to argue for them.

