Duo

A Duo is an instance designed for completion by two players working cooperatively. Currently, there are five duos available in DC Universe Online.

Access
In order to enter a Duo, players must queue up using the group tool (Default PC Key 'Y'), and choose appropriate roles they wish to fulfill. They will then be placed in a queue that searches for other players who wish to do the same duo, and be prompted to enter the instance.

Rewards
Upon completing a Duo, players will receive 2 Marks of Triumph, in addition to any loot the boss happens to drop. Additionally, if the Duo was marked as Daily the by a star, players will receive 1 Mark of Distinction.

Cape Carmine Lighthouse
Bane has been using this lighthouse as a base to supply his gang with Venom. Accompany Nightwing or Killer Croc inside and stop him.
 * Venom Supplier Diego
 * Killer Croc (heroes)
 * Deathstroke (heroes)
 * Nightwing (villains)
 * Huntress (villains)
 * Bane

Gotham University
In the Gotham University Duo, players fight off the soulless minions of Faust as they attempt to prevent him from resurrecting Isis, Black Adam's deceased lover, in an attempt to steal the powers of Shazam.

Bosses:
 * Soulless Lord
 * Necro Magent Gruhn
 * Undead Isis

HIVE Base
In the HIVE Base Duo, players face off against Queen Bee's minions, as well as an enslaved Booster Gold.

Bosses:
 * Major Honeygut
 * Captain Bumble
 * Booster Gold
 * Queen Bee (Zazzala)

Metropolis Hall
For heroes, the player must go to the Metropolis city hall to fight off Sinestro, Manhunter and Arkillo.

Bosses:
 * Manhunter (heroes)
 * Arkillo (heroes)
 * Sinestro (heroes)
 * Alpha Lantern (villains)
 * Kilowog (villains)
 * John Stewart (villains)

OMAC Base
In the OMAC Base Duo, players assist Fire or Killer Frost (depending on faction) in travelling to the Gotham sewer in order to put a stop to Brother Eye's nefarious plans.

Bosses:
 * OMAC Incinerator
 * OMAC Delta
 * OMAC Sigma

Gorilla Grodd's Laboratory
In the Underground Laboratory Duo, players fight against Gorilla Grodd's devolved humans and gorilla minions, eventually assisting The Flash to defeat him. Heroes only.

Bosses:
 * Captain Shortly
 * Zoom
 * Gorilla Grodd

Gotham Old Subway
The Penguin has made a base in the old subway system, and Two-Face has tasked you with taking him out, Heroes only.
 * Hush or Bane
 * Clayface
 * Penguin

Gotham Mercy Hospital
In the Gotham Mercy Hospital, players must infiltrate Mr. Freeze's stronghold and steal his research for The Joker, then fight their way out. Villains only.

Bosses:
 * Coldcut
 * Two-Face
 * Mr. Freeze