I always say to do
- main quest
- alliance quest
- clear zones of dolmens, delves, group event, skyshards, lore books as you go
- fighters / mages either as you go or rattle through it in one hot to keep the story fresher.
Great XP, relevant story, and sorts a few skill lines you will need out.
In the vanilla game original release, several quest lines meet up in Coldharbour at the point where there’s a sort of council meeting.
- the main story quest
- the mages guild quest, approx six quests that proceed by collecting blue books and leaving the skill line.
- the fighters guild quest, approx six quests that proceed by leveling the line by killing undead and daedra and closing dolmens.
- each of the three faction quest lines, which start in the zone one starter city and progress through all five zones with ~5 multi-stage, major quests in each zone (and three skill points per zone).
Note that the faction quests can be confusing because of One Tamriel and the ability to go anywhere. Not only can you run all three factions at the same time, the quests in these lines can be run in multiple zones within a faction at the same time. In other words, Auridon sets the state for Queen Ayren’s situation. But you can pick up the Dominion quest at the entrance of Reapers before completing Auridon, and jump into the middle of the story. This can be really confusing. To prevent getting lost, as you run a faction quest line always pick up the next quest at the location where you complete one. There will always be a quest giver pointing you along the path.
In the original release, you did not have to complete any of the other lines to finish the main quest. You could not complete more than one faction, because you were not allowed into the other areas until you’d completed the main story quest. You can complete however many of them as you like...but the more you do, the higher level you’ll be when you go to coldharbour. This isn’t a problem, it’s just if you were to run all three factions you’d be way, way into vet by the time you wrapped the main line.
After the main quest
The dlc quest lines occur after the main story. However, they’re designed so you can’t really tell and there aren’t any spoilers. You occasionally meet familiar characters, but the quests are written in a way where you could be meeting them before or after your Morag bol adventures. These quest lines currently are:
- Craglorn, a major storyline through the zone
- Imperial city, a really loose story inside IC
- Wrothgar, major line w/ skill points
- Hew’s Bane and Gold Coast, major lines w skill points through the guilds in those zone
- vvardenfell, two major lines and multiple area quests. This zone is designed to be played in any order and can be considered before or after the main quest.
- Clockwork City, a major line w/ points.
The dlcs vaguely reference one another in the Ryder they were released. They can be played in any order, though.