It only took ten years and a lot of tenacity, but modders have finally made Skyrim co-op and it genuinely mostly works.
On my first night of Skyrim Together Reborn, my party and I tried to use about 15 total mods, which was a mistake. All four ill-fated party members crashed to desktop multiple times and, although we had a good laugh about it, it was chaos. There were invisible horses and floating NPCs. Our mod eyes had been bigger than our mod stomachs. Classic Skyrim hubris.
On the second night, we cut down on our mod list (and player list), and found that Skyrim Together really does work if you keep your ambitions within reason. It's co-op Skyrim as advertised, without too many more fiddly bugs than Skyrim already has.
For that second attempt, my partner and I removed as many complicating variables as possible. We played over LAN with the server executable running on my machine, with only Skyrim Together Reborn, its dependencies, the unofficial Skyrim SE patch, and the Alternate Start mod installed.
Getting together on our LAN server was a breeze. Starting a party took only a couple clicks. Teleporting to each other, while maybe an inelegant workaround to seeing one another on the map or compass, was easy and efficient too. Questing, once we agreed on a party leader, went smoother than I'd expected, with my dialogue choice responses printed out in the server chat box and quests showing up in my partner's log after I'd accepted them.
We met each other in Riverwood and jaunted off to classic first dungeon Bleak Falls Barrow to retrieve yon golden claw from the clutches of bandits, spiders, and draugr. On the way, we did find a bandit in the overworld that attacked my partner, but was invisible and intangible to me. Once inside the dungeon, though, things were smoother. It was a bit of a toss-up in each combat encounter how Skyrim's AI would handle the both of us. Occasionally my partner got entirely ignored by enemies who chased me, presumably because I was the quest holder.
That worked in my favor. Skyrim's melee combat turned out to be a bit more deadly without the ability to enter a menu and scarf a healing potion, skeever leg, and stew while a draugr's axe is paused in the air an inch from my face. A bit of AI merry-go-round the dungeon pillars with a giant spider was much needed without pause-scumming.
Aside from the AI's tunnel vision, fighting together through a short dungeon was surprisingly functional. I was able to pick locks on chests for my partner without him needing to do so separately. Loot from corpses and containers was shared, too. Our only minor world state hiccup while inside Bleak Falls was him nicking the golden claw off the thief and using it on the relevant door, walking through what was still a locked, solid door on my end. No worries, though: He was able to toss it on the ground for me to repeat the process.
What Skyrim Together does require is a lot of communication. There's server text chat if you need it, but I'd recommend jumping in a Discord call. We found ourselves saying "wait, where are you?" pretty regularly as I instinctively pulled open my map each time before remembering that no, my friends weren't visible there. Sticking together, or making liberal use of that teleport function in the party menu, is key.
Oh, and for the extreme scummers in the room: With PvP disabled you can smack your friends with weapons over and over to quickly gain experience and level up. It's a whole new way to cheese the level grind.
It's been a few years since I played through Skyrim's early hours and it was fun getting to revisit it with my partner, who's thus far managed to never, ever play it. Skyrim Together really isn't the ideal first experience with The Elder Scrolls 5 though. I wouldn't recommend it as an introduction to anyone who isn't my legally bound co-op guinea pig.
But for Skyrim vets who want to have a laugh with pals? It's great. So long as you're willing to shrug off occasional AI hiccups, naked NPCs, and invisible bandits. This isn't an immersion-enhancing Skyrim experience. But it does what it says on the tin better than I'd expected without being a pain in the ass to set up—at least, no more of a pain in the ass than Skyrim modding has always been.
You can download Skyrim Together Reborn and find its installation instructions over on Nexus mods and learn about setting up a server with playtogether.gg or Hamachi on its website.