Borderlands 2 was officially announced on August 3rd, 2011. The game was released on September 18, 2012 in the United States, September 20, 2012 in the Australasia region and September 21, 2012 internationally. Borderlands 2 was built in Unreal Engine 3 and uses PhysX technology. It was announced by Randy Pitchford,Gearbox CEO, that the game sold over 12 millions units by March 2015 on all platforms.
Set five years after the events of Borderlands; Handsome Jack, the game's main antagonist, has taken over the Hyperion Corporation, declared himself Dictator of Pandora and taken all of the credit for finding the Vault -- going so far as to claim responsibility for killing the Destroyer. Jack has also blotted out much of the light on the planet by having a giant orbiting H-shaped base set in front of Pandora's stationary moon, creating a 'big brother' atmosphere throughout the planet. The new group of Vault Hunters in Borderlands 2 are tasked with killing Jack and returning peace to Pandora.
Borderlands 2 begins with the protagonists on a train to an unspecified location to begin their search for the vault. The train turns out to be a trap set by Handsome Jack, to kill all who search for the Vault. The Vault Hunters defend themselves long enough to reach a train car filled with explosives and a 'dummy' Handsome Jack look-a-like. The detonation causes the train to crash in the Arctic Wasteland, with our new team strewn across the wreckage. The game picks up with the Vault Hunters waking up to Claptrap digging through the remains. The mysterious Guardian Angel then contacts them and explains that Handsome Jack must be killed, directing players to rescue the four original Vault hunters from Hyperion's clutches to accomplish this.
All four of the original Vault Hunters reappear in the sequel as NPCs, taking a pivotal role during the main storyline and offering optional missions that continue their personal story.
- Main article: Borderlands 2 mission flow
Borderlands 2 initially has four player-characters:
- Dr. Zed
- Mad Moxxi
- Marcus Kincaid
- Michael Mamaril
- Patricia Tannis
- Sir Hammerlock
- Tiny Tina
- Crazy Earl
- Main article: Borderlands 2 Enemies
DLC only vehicles:
- Sand Skiff (Captain Scarlett and Her Pirate's Booty)
- Bike ° (Mr. Torgue's Campaign of Carnage)
- Fan Boat (Sir Hammerlock's Big Game Hunt)
° These vehicles are only used by NPCs and cannot be legitimately driven by players
- Windshear Waste - Arctic region
- Southern Shelf and Bay - Arctic regions
- Three Horns - Divide and Valley - Arctic/Highland regions
- Sanctuary - Urban region
- Frostburn Canyon - Arctic region
- The Dust - Desert region
- Tundra Express - Arctic region
- The Fridge - Arctic region
- The Highlands and Outwash - Highland region
- Caustic Caverns - Acid-soaked caverns
- Wildlife Exploitation Preserve - Highland region, Hyperion research complex
- Lynchwood - Desert region
- Thousand Cuts - Highland region
- Opportunity - Urban region
- Eridium Blight - Blight region
- Sawtooth Cauldron - Desert region
- Arid Nexus - Boneyard and Badlands - Blight/Desert regions
- Bandit brand weapons - Bandits themselves now make many of their own weapons. These weapons sport the largest magazines in the game, but have mediocre stats overall.
- Dahl's weapons focus on stability, precision and burst fire, and feature camouflage coloring. Most Dahl weapons feature a full auto fire rate without scoping in, while scoped in the gun shoots in bursts.
- Hyperion weapons retain their customary high accuracy, with a "sci-fi" styling, featuring glowing elemental effects and bold stripes. Unlike with other weapons, the accuracy of Hyperion weapons increases the longer the trigger is pressed, but they start off with low accuracy.
- Jakobs weapons retain their tradition of high non-elemental damage (with exception to a few weapons) for high recoil and low magazine sizes, but have undergone a slight revamp from the previous installment. Assault rifles, shotguns and pistols fire as fast as the trigger is pulled, while sniper rifles still require a wait for the round to be chambered.
- Maliwan weapons retain their focus on elemental damage, and take on a very sleek and futuristic design, with rounded corners, bright colors and many blinking lights.
- Tediore weapons have a different feel, having been described as "Cheap, plastic pieces of crap" and "Wal-Mart guns" by Randy Pitchford. Instead of being reloaded, Tediore weapons are thrown away and explode like grenades; the more ammo left in the clip, the bigger the explosion. A fully-loaded gun digistructs in the character's hand after the expended weapon is discarded. Pre-release promotions stated that, due to their explosive capabilities, there is a chance that Tediore weapons would explode in the user's hand before throwing it away. This mechanic did not make it into the finished product.
- Torgue weapons feature Gyrojet ammunition which balance area-of-effect damage with low projectile velocity and reduced magazine capacity.
- Vladof continues their tradition of weapons with extremely high rates of fire, and produce rotating minigun-like barrels. Vladof use materials that range from weathered wood to chrome like metals.
- Character customization - New gear, skins, and "heads" are available as drops from bosses and certain enemies and as mission, challenge, and levelling rewards. They feature varying grades of rarity.
- E-tech - A holdover from Borderlands Eridian weapons, E-tech is a barrel modification technique that works with all brands of weapons. 
- Badass Rank - Completing challenges increases Badass Rank, and the harder or higher level the challenge is, the more Badass Rank is given upon completion. Earning enough rank awards a Badass Token, redeemable for stat increases that apply to all characters of a profile.
- Optional objectives - There are now objectives that are not required (like keeping an ally above 50% health). Rewards are being tabulated.
- Elemental Nerfing - Where Borderlands elemental-based enemies could be killed with sheer bullet damage from a similarly based elemental weapon, Borderlands 2 enemies will take significantly less damage from weapons utilizing elements they have a resistance to.
- Multiple Choice Missions - Some missions will feature a choice in how they will be completed.
- Trading Interface - A trading system was created allowing players to formally trade or sell items. Players can also wager items to be dueled for.
- Traps - Some normally loot-dropping items (chests, plant pods, etc.) contain traps, from hostile enemies to live grenades.
- One Point Wonders - "Game changer" skills that can change available options and gameplay style but only require a small investment to unlock at a basic level.
- Eridium - A new element that can be used to augment other elemental powers. It is also a currency that can be used to upgrade backpack space capacity, weapon bank space, weapon ammo capacity, temporarily upgrade character abilities, and open special chests (DLC only)
- Premiere Club - Pre-Order bonus includes:
- The Golden Key - "Unlock a rare item in the mysterious Sanctuary Loot Chest."
- Vault Hunter's Relic - "Play solo or team up with friends and boost your gear hunting fortune with the Vault Hunter's Relic."
- Gearbox Gunpack - "A package of unique Gearbox Golden Guns to help you start your journey on Pandora."
- Consumers who pre-ordered Borderlands 2 received the Mechromancer DLC free of charge.
- Consumers who pre-ordered from GameStop (US), EB Games (AU/NZ/CAN) or GAME (UK) also received access to the Creature Slaughter Dome. Consumers were also able to submit their idea for the name of a gun to be included in a future add-on content pack on GameStop's Facebook Page: Name This Gun!. (Yellow Jacket)
- Deluxe Vault Hunter Edition
- Ultimate Loot Chest Edition
- Game of the Year Edition (2nd UVHM Paid Patch Not Included)
- Borderlands 2 Season Pass - 4 DLCs (not including pre-order packages)
- Borderlands 2 PlayStation Vita Bundle
- Borderlands Triple Pack includes all DLC on PS3 and Xbox 360
- Borderlands The Handsome Collection includes all DLC on PS4 and Xbox One
- The intro song of Borderlands 2 is "Short Change Hero" by The Heavy.
- The credit song of Borderlands 2 is "How You Like Me Now" also by The Heavy.
- Borderlands 2 is considered by many critics and players alike, the best Borderlands game in the series to date.
- The Psycho on the cover makes the gun gesture with both hands and aims them at his head again. This is a repeat of the cover of the first game, where a Psycho makes the gun gesture with one hand and aims it at his head (Borderlands -> Borderlands 2).