There is not much in-game information regarding One-Eyed Jack, only that he is a bandit leader in Rust Commons West. His bandits are unusually well armed, reportedly being supplied by a source other than Marcus Kincaid. It is later revealed that One-Eyed Jack and his crew have been discretely receiving arms shipments from Torgue.
The Vault hunters encounter One-eyed Jack while completing side missions from Marcus. After completing Firepower: Market Correction, and having destroyed a number of bandit ammunition caches in the process, Helena Pierce fears One-Eyed Jack will attack New Haven in revenge. She responds by sending the Vault hunters to launch a pre-emptive strike on One-eyed Jack in order to prevent her fears from coming true.
- Main article: Jack's Other Eye
- "I'm gonna make you drown in blood for that!"
- "You remind me of my mother. I ate my mother."
- "I'm gonna tear your arm off and beat your baby with it!"
- "Did you know your head is really a big tomato?"
- "Can I play 'pop top' with your head?"
- "I'm gonna squeeze you till you bleed blood." - This quote is from the DLC Mad Moxxi's Underdome Riot.
- "You woke the wrong dog!" - This quote is from the DLC Mad Moxxi's Underdome Riot and is probably a glitch as this is originally Nine Toes' quote.
- Unlike other bosses, it's possible to end the fight with Jack quickly by running him over with a vehicle. On the other hand, Jack can be a dangerous opponent to fight on foot because of his high-damage revolver.
- The item "Jack's other eye" is represented in game by a Skag pearl.
- He looks similar to a psycho, although he uses his gun, Madjack, rather than melee weapons.
- A 'one-eyed jack' is a common playing card term used to refer to two of the jack cards which show the face in profile, thus presenting only one eye.
- Nobody knows where One-Eyed Jack came from. Marcus suspects that he's a black market weapons dealer, and that his bandit persona is simply a front. It's rumored that he lost his eye in a poker game, to an inside straight flush. (From the Official Borderlands Guide)