Marcus was originally an arms dealer allied with either the Dahl or Atlas corporations before the Vault Hunters made their way to the planet. His current affiliations are unknown, although he maintains a mercenary outlook on life, which has him dealing frequently with the main characters. He sells weapons from all except the Eridian and Gearbox weapon manufacturers. During Borderlands he is the only current purveyor of weapons, while in Borderlands 2 he is the only non-Hyperion weapons purveyor. Despite his numerous weapon vendors and advertisements for his business, it is written in very small text, on his vendors that he is in fact, "unauthorized" to sell weapons on the planet.
It is also hinted that Marcus also sold daily supplies to Pandora residents, as he is the first person to be suspicious of where Patricia Tannis's supply comes from, due to the fact that she never buys from him.
As an aggressive merchant with almost no morals, Marcus is extremely greedy and will devote all efforts to maximize profits, going as far as killing rivals and destroying their stock, supplying weapons to every possible buyer, and maintains a no-refunds policy. Despite his aggressive business dealings and capitalist ideals, Marcus is shown to be very acquainted with the Vault Hunters. After Roland's death, Marcus is visibly saddened, despite Roland criticizing him for supplying weapons to bandits previously. In The Talon of God, if interacted with, he gives the Vault Hunters a free weapon, not because Hyperion is disrupting his arms trade, but because Handsome Jack is a "greedy murdering sonofabitch who needs to die screaming."
Marcus is the driver of the bus that brings the original four Vault Hunters to the town of Fyrestone at the beginning of Borderlands. After the Vault Hunters complete some tasks around Fyrestone, Marcus opens up his weapon and ammo vendors in the town. He runs and maintains the weapon and ammo vendors found throughout Pandora. Marcus himself lives in New Haven, and offers a few optional missions when the Vault Hunters arrive there.
In Mad Moxxi's Underdome Riot, Marcus is revealed to have been Mad Moxxi's third husband. While he does not personally appear in that DLC, he still provides his services to the Vault Hunters, such as with the new Marcus Bank.
Between the events of Borderlands and Borderlands 2, Marcus moved to Sanctuary at Roland's request. However, he sells weapons to both the Crimson Raiders and Bloodshots, the latter treating him like a god and having created a shrine at Bloodshot Ramparts.
Marcus is also the main mission provider in How Marcus Saved Mercenary Day.
Between the events of Borderlands 2 and Borderlands 3, Marcus, after realizing that Atlas installed brickware on their weapons to disable them, was about to sell them to unsuspecting bandits. He was approached by Rhys for a partnership, although Marcus refused as he considers Atlas' revival impossible. When Rhys managed to restore Atlas, however, Marcus conceded and they agreed upon a rocky partnership.
In Borderlands 3, Marcus, in addition to vending weapons, now also sells SDUs for money.
In Powerful Connections, Marcus, angry at the unpowered vending machine harming his profits, requests the Vault Hunters to find a skag/human spine to repair it. If the human spine was used, Marcus would be amused and grant the Vault Hunters a hidden weapons stash as their reward for killing COV bandits suspected of damaging his vendors.
During Sanctuary, he asks the Vault Hunters to activate the sprinklers in order to extinguish his burning firing range.
In Claw and Order, Marcus asks the Vault Hunters to find incriminating evidence on Maurice, whom he suspects of having hostile intentions and "eating people", despite clear evidence of the contrary. His efforts fail and he begrudgingly accepts Maurice's explanation and "gift" when the latter becomes aware of the misunderstanding.
- New Haven
- T-Bone Junction
- Tartarus Station
- Rock, Paper, Genocide: Fire Weapons!
- Rock, Paper, Genocide: Shock Weapons!
- Rock, Paper, Genocide: Corrosive Weapons!
- Rock, Paper, Genocide: Slag Weapons!
- Safe and Sound
- The Chosen One
- The Secret Armory of General Knoxx
- Claptrap's New Robot Revolution
- Borderlands 2
- How Marcus Saved Mercenary Day
- Tales from the Borderlands
- Commander Lilith & the Fight for Sanctuary
- Borderlands 3
- Main article: Marcus Kincaid/Quotes
- See also: Ammunition Vending Machine Quotes
- See also: Weapon Vending Machine Quotes
- In Borderlands 2, when shopping from Marcus in Sanctuary directly, audio clips from the vending machine are still played.
- Marcus is the primary narrator of many of the introduction movies at the start of the Borderlands games.
- Not only does Marcus sell most of the guns and ammunition on Pandora, but he even has his own set of playing cards. In Treacher's Landing, where the You're on a boat! achievement can be obtained, there is a box with several playing cards on top of it. One side of each card features Marcus's business logo, while the other shows the card number and suit (a pair of queens can be seen).
- On Marcus's weapon vendors, it is written in very small text that he is in fact "unauthorized" to sell weapons on the planet.
- In The Zombie Island of Dr. Ned, Marcus Kincaid was spelled as "Marcus kincaid", missing the capitalization in his last name.
- In the trailer for Mad Moxxi's Underdome Riot it is hinted that Mad Moxxi was, at one point, married to Marcus. She describes her third husband as being "good with numbers" with the trailer also showing a bobblehead and his bus. This is proven in Safe and Sound with Mad Moxxi specifically mentioning Marcus as being her "third ex-husband".
- He allegedly comes from seven generations of weapon dealers. There is a portrait of Marcus, (along with Marcus II, III, and IV), hanging on the wall of the bank in the Underdome, as well as on the walls of his shop in T-Bone Junction.
- At the end of Claptrap's New Robot Revolution during Marcus's staged death (which he made up in the framing story to "keep the ladies hanging around"), he references the Jakobs motto, "If it took more than one shot, you weren't using a Jakobs!" in his dying words.
- Marcus has attempted to date Tannis, as evidenced by dialogue in the missions Old Spicy and Eleven Rakk And Spices, as well as by the end credits of Claptrap's New Robot Revolution. While he states that the date failed thanks to Tannis standing him up, Marcus later reveals that he made that up.
- In Borderlands 2, all vending machines have batteries attached to the top right corner and they read "Energy by Marcus".
- After Sanctuary gets relocated, his name changes from Marcus Kincaid to just Marcus when sighted in gun crosshairs.
- Marcus credits his obesity to advice from Mad Moxxi that suggested that when he looked weak, people would heavily underestimate him.
- Marcus has considered having a child to continue his family line of weapon dealers. He has even picked the name "Varcus" which he claims is a unisex name.
- Although Marcus does not appear in the Pre-Sequel, his vending machines are still active on Elpis.