In Frostburn Canyon, an error message can be found on a monitor with a humorous message stating that the user has damaged their computer due to viewing pornography.

The full message reads:

Torgue vending machines in the Campaign of Carnage DLC all have 80085 typed into the selection box, an obvious reference to the juvenile joke of spelling the word "BOOBS" out on a calculator.

The Bane's vocal effects will still play even after lowering all of the game's volume settings.

Spoiler:After Mordecai shoots Bloodwing with a tranquilizer dart at the end of her boss fight, it is possible to shoot her after she falls to the ground. Even though she is defeated, every shot fired at her head will still count as critical hits in your Badass Ranks.

During a second playthrough on "True Vault Hunter Mode", after the chapter "Where Angels Fear to Tread", the player can go to Claptraps Place and find an event item in the fireplace called "Geary's Unbreakable Gear" with the description "Only a brisk walk to Eridium Blight will reward the courier". The player must then travel to Mount Hellsfont, located in the northwest corner of Eridium Blight without dying, using a fast-travel station, or riding in a vehicle spawned from a "Catch-A-Ride" station. If the player is successful, they'll encounter a special enemy named Geary. If the player lets Geary attack them, he'll steal the gear and jump into the lava. This will cause three Rakks to appear and drop three loot chests, one of which will have purple gear. This is a reference to "The Lord of the Rings" book trilogy by J.R.R Tolkien, and the journey to Mount Doom.

The Baby Maker SMG explodes into two smaller versions of itself when reloaded. The chances of spawning a pink or blue variation are actually based on US birth statistics for females and males.

The optional mission in Sir Hammerlock's Big Game Hunt, "Still Just a Borok in a Cage", is a reference to The Smashing Pumpkins song, "Bullet With Butterfly Wings." More specifically it's a reference to lyrics for the chorus, "Despite all my rage, I am still just a rat in a cage."

The side quest "Raiders of the Last Boss" in the Tiny Tina's Assault on Dragon Keep DLC is a clear reference to the Indiana Jones movie "Raiders of the Lost Ark."

Handsome Jack had dialogue recorded for the New-U Station revival taunts, but they were unused in the final release.

The inside cover artwork for the game was based on artist Olly Moss's art style of his homages to various franchises, however, the clouds in the artwork were taken directly from one of Moss's own pieces; from his Star Wars: The Empire Strikes Back fan poster.

When Moss found out, he took to Twitter to express his disappointment, however, Gearbox CEO, Randy Pitchford, soon contacted him and apologized for the incident.

The sidequest, "Too Close for Missiles", contains a large number of reference to the film "Top Gun". The quest starts after talking to Loggins (a reference to Kenny Loggins, the writer of the song "Danger Zone" from the film's soundtrack) outside of Ellie's garage. During the mission, Loggins will repeatedly call the player "Goose", in reference to Maverick's wingman. The mission involves gathering volleyballs and gasoline to light a volleyball net on fire. Following that, 3 NPCs known as Shirtless Men spawn and attack the player. All of the objectives reference the infamous sand volleyball scene from the film. Loggins himself also says "Danger zone" multiple times during the quest.

The side mission "Rocko's Modern Strife" is a reference to the show Rocko's Modern Life.

Tiny Tina's Assault on Dragon Keep contains a reference to the YouTube user "Bro Team Pill". At the end of the optional mission "My Dead Brother", one of the mission completion messages reads "Bro Team Kill".

In a Reddit AMA, Borderlands 2 Lead Writer Anthony Burch said his inspiration for creating the NPC Face McShooty, the character that demands you shoot him in the face, was the "Close Range" video on The Onion, featuring a fictional video game in which the only gameplay is shooting people in their faces.

"That was mine. I saw this video...and thought it was hilarious, and thought we could play off the idea with Face McShooty." -Anthony Burch

The Bane side mission, and weapon, are both based off of the 1950's Western movie "Winchester '73" starring James Stewart. The movie revolves around a cursed rifle that leads to the death of anyone possessing it.

Tiny Tina's lazy eye is actually a bug in the software. Instead of fixing her eye tracking, the developers thought that it fit with her character, so they decided to leave it in the game.

Mister Torgue is censored by a device in his voicebox, rather than being edited later. In his own words:

The red flavor text for the Buffalo gun refers to three notable linguistic constructions:
a sentence that uses the word "buffalo" 9 times and is still grammatically correct, a sentence that repeats the word "had" 11 times to illustrate the importance of punctuation, and a Chinese poem that tells a story using a total of 92 words, which are all pronounced in varying tones of "Shi".

The commando for Borderlands 2, Axton, has been confirmed as bisexual by Borderlands 2 lead writer Anthony Burch.

The "these pretzels suck" and Butt Stallion dialogue spoken by Handsome Jack were ad-libbed by voice actor Dameon Clarke. Writer Anthony Burch was upset that these became Handsome Jack's most popular lines as he had no hand in writing them.