Selecting a Mentor in DC Universe Online doesn't just determine your starting area, it also determines the quest lines you follow throughout the game. Each Mentor provides a mission at level 1, level 15, and level 30 for their Heroes or Villains. The only way to access an Instance from a mission from a mentor other then your own is to join a team with someone who has access and let them enter the instance first.
- Main Article: Meta Hero Storyline
Meta Heroes chose Superman as their Mentor. They begin in Metropolis's Little Bohemia, where Gorilla Grodd has invaded and is transforming citizens into gorillas. It is up to the new Hero, fresh off the Brainiac Harvester Ship to stop him (with a little guidance from Superman). At level 15, Superman provides his Heroes with a new quest. Lex Luthor has invaded a STAR Lab Secret Facility and is stealing their Exobyte research. Superman asks for the Hero's help in bringing him to justice. Superman and the Hero fight side by side, but Lex Luthor escapes. The Meta story line culminates at level 30, when the Hero gets to meet with Superman in person, on the Watchtower. Superman gives the Hero their most important Mission yet, to beat Lex Luthor once and for all in the Hall of Doom.
- Main Article: Tech Hero Storyline
Tech Heroes chose Batman as their Mentor. They begin in Gotham City's East End, where Scarecrow has been releasing Fear Gas into the streets. It is up to the new Hero, fresh off the Brainiac Harvester Ship to stop him (with a little guidance from Batman). At level 15, Batman provides his Heroes with a new quest. Joker has developed a new toxin and is planning to use it on the Gotham City Special Crimes Unit while they are all off duty at the Regal Hotel. Batman asks for the Hero's help in bringing him to justice. Batman and the Hero fight side by side, but Joker escapes. The Tech story line culminates at level 30, when the Hero gets to meet with Batman in person, on the Watchtower. Batman gives the Hero their most important Mission yet, to stop Joker's plans once and for all by bringing down the source of his toxin, T.O. Morrow.
- Main Article: Magic Hero Storyline
Magic Heroes chose Wonder Woman as their Mentor. They begin in Metropolis's Chinatown, where Felix Faust has invaded and is stealing citizens' souls. It is up to the new Hero, fresh off the Brainiac Harvester Ship to stop him (with a little guidance from Wonder Woman). At level 15, Wonder Woman provides her Heroes with a new quest : preventing Circe from stealing magic exobytes at her headquarter Chinatown Cafe with a little help of Wonder Woman and her Amazons. At level 30, you head to the Oblivion Bar to help Wonder Woman and Circe in stopping Brainiac from invading the realm of magic.
- Main article: Meta Villain Storyline
- Meta Villains chose Lex Luthor as their Mentor. They begin in Metropolis's Little Bohemia, where Lex Luthor is developing a method to take down the new super heroes by transforming them into copies of Parasite. Lex Luthor needs the help of the new Villain to help him finish the tests and prevent Power Girl from stopping them.
- At level 15, Lex Luthor provides his Villains with a new quest to steal exobytes research from the Old Star Labs installations, in two instances where you fight Steel and Superman himself.
- At level 30, villians will fight against Steel, Zatanna, and Superman himself in the Watchtower.
- Main Article: Tech Villain Storyline
- Tech Villains chose The Joker as their Mentor. They begin in Gotham's North Burnley, where a gang war has erupted. New Villains are first enlisted to aid the Falcone Mob who are under siege by the Gotham Police Department. During the conflict they assist Catwoman in robbing a warehouse, despite interference from Huntress.
- At level 15 the Joker has his Villains lead a group of his men to attack the Gotham Police at a meeting in the East Regal Hotel, after driving the Police back they find The Joker locked in a fight with Batman who they distract long enough to allow The Joker's escape.
- At level 30 Tech Villains team up with The Joker to fight against Brainiac who has taken control of a satellite owned by the traitorous T.O. Morrow. The Villains manage to save The Joker and Harley Quinn from a modified form of their own toxin as well as an assault from Batman and Robin. With The Joker incapacitated they assault the satellite singlehandedly and save The Joker once again from a robotic duplicate of himself.
- Main Article: Magic Villain Storyline
- Magic Villains chose Circe as their Mentor. They begin in Metropolis's Chinatown, where they battle the Sentinels of Magic, eventually confronting Doctor Fate alongside Brother Blood.
- At Level 15, she will call on Magic villains to help her drive off Wonder Woman and the Amazons trying to recover the magic based exobytes she's collected.
- At Level 30, Circe will call villains to help save the magical planes from Brainiac. In the Shadowlands, after helping you drive off Brainiac's forces with Wonder Woman, Circe will turn on her, only to be trapped by her Lasso. Villains will have to defeat Wonder Woman and free Circe, only to threaten her by trapping her in the Shadowlands unless she recognizes you as more than a tool.