While fighters and knight-like characters have the Companions, rogues have the Thieves Guild and assassins have the Dark Brotherhood, mages have the College of Winterhold as their place to practice magic and other silly things. It’s a great place to do potentially really, really dangerous things. Unfortunately, it’s not exactly… impressive.
Quick warning, spoilers ahead, but you knew that.
The College of Winterhold is located in Winterhold, obviously. Really, it’s the only thing IN Winterhold, apart from a couple of houses. Considering that it’s the only thing that’s intact in the small, formerly busy town, there’s a lot of suspicion and anger around it. Many people believe that the College had something to do with the town’s destruction and falling into the sea in 122 in the Fourth Era (about 80 years before the events of Skyrim). Of course, the College claims they had nothing to do with it, and an earthquake caused by the eruption of the Red Mountain in Morrowind are to blame for the city falling into the sea. Really, though, considering that the College is one of the very few structures remaining, they seem incredibly suspicious.
Annoyingly, you often have to join the College of Winterhold during the main quest, while looking for an Elder Scroll. The only guy who has any idea is Urag gro-Shub, a very intelligent Orc who maintains the great library in the College. He points you in the direction of Septimus, who sends you wandering around Dwemer fortresses. Either way, it’s nice to see someone who breaks stereotypes.
Everyone else is either a student, a scholar or a general mage, with little in between. Among them is one of the most powerful followers in the base game, the Khajiit student J’zargo. The two other students are available as followers as well, but J’zargo is best. Everyone else is just a standard quest-giving NPC, apart from Ancano, who is simply a cunt.
You can join the College of Winterhold outside of the main quest. Simply by going up to the woman, Faralda, standing at the entrance, you can ask to join the college. She’ll ask you why, then ask you to cast a spell, selling the required spell tome for 30 gold if you don’t have it. If you’re Dragonborn, she’ll let you in. If you’ve got a high enough Speech level, you can talk your way in, but you need level 100 (or level 70 with the Persuasion perk) to be able to sass your way through. Just make sure there’s no enemies around or otherwise Faralda will bug out.
Students can then go on a tour of the college, you’re given a room and can then attend a lesson. The tour is optional and you can just wait or run around or summon dragons or whatever. The lesson is basically casting a ward, and then you all go to Saarthal for a school trip.
From there on, things just get worse. You find a gigantic magic artifact, you find some books to find out what it is, you ask a magical guy for even more information, look for even more information to find a staff to stop the magic artifact, realise everything is going bad, there’s magical anomalies everywheere and that Ancano really is a cunt, having killed the Arch-Mage. After all that, you go off and and find a magic staff, only to find that the Arch-Mage is a bit of a coward and left his friends to die in the large Nordic maze that the magic staff is located in, only to bring it back to the college and fight a buggy fight against Ancano, who’s trying to use the Eye of Magnus – the gigantic magic artifact found earlier – to destroy the world.
Once you kill Ancano, you don’t even get to try and contain the giant magic artifact. A member of the ‘Psijic Order’ comes along and cleanly tidies everything away, and all of a sudden, you’re proclaimed Arch-Mage of the college.
After that, there’s very little to do, just the endless repeating mini-quests that every guild has. Some of the NPCs have their own quests, for example, the three students all have quests that allow them to become followers later on, but many of these are just fetch and grab quests that no one really likes.
It’s all kinda… weird. The whole story feels like there’s supposed to be way more to it. Way more lessons, more climbing the ranks, more actual magic-science stuff. You get introduced to the Psijic Order, but unlike the Nightingales from the Thieves Guild or the Circle in the Companions, it’s just some NPC only secret cult. Which is a shame because they have awesome teleporting and psychic abilities.
Most people assume that the lack of content is because of the rush to meet the 11/11/11 deadline, and that’s probably the case. There’s several unimplemented mini-quests, including a quest where you hunt down a rogue mage, and another where you find out what happened to a bunch of former students. All this and more seems to be missing, making the College in general almost as ruined as Winterhold itself.
The weirdest thing though is how you complete the questline in general. You can complete the majority of the questline by casting only a handful of spells. Even a rampaging Orc in heavy armour and a mace can become Arch-Mage of the College of Winterhold. That seems to be a running theme among guilds in Skyrim, it seems.