During the opening, you are shown inkblots in order to test your mental health. Fans thought that one of the inkblots looked like two bears high-fiving, but this was not an option in the game. A fan decided to make a mod for the game which made 'Two Bears High-Fiving' an option. Obsidian referenced the fan reaction and the mod by putting a character called 'Two-Bears-High-Fiving' in the game's Honest Hearts DLC.

The weapon Fat Man and its mod Little Boy are named after two atomic bombs that were dropped on Hiroshima (August 6th) and Nagasaki (August 9th) in Japan during the end of the World War II. In the Japanese version, the name Fat Man is changed to "Nuka Launcher," yet the Little Boy Kit kept its name. The changes were made to avoid offending the people of Japan, though Japanese gamers generally didn't approve of the change.

There's a fossilized dog called Seymour in the Lonesome Road DLC. Seymour has the appearance of a normal dog, but at a reduced size. His inclusion in the game is a reference to the Futurama episode "Jurassic Bark" in which Fry finds his dog Seymour fossilized and tries to clone him.

The project director for Fallout: New Vegas, J.E. Sawyer, released a mod for the game which brings more difficulty, shifts certain NPC alignments and modifies a few character stats.

The reason this wasn't released as an official patch was partly due to its technical difficulties and difficulty curve, however it was mainly due to the development for the game and all DLC having ended.

Indiana Jones' remains (hat included) can be found inside a refrigerator, mocking a scene in the fourth film where Jones survives a nuclear blast by hiding in a fridge.

In Fallout 3, and New Vegas, a weapon can be found called the Fat Man, a Tactical Nuke Launcher.

When you fire it, it throws a mini nuke ahead of you at the enemy. When you reload you hear a "ding" sound to indicate it has finished reloading.

The bell heard is actually the Bethesda lunch room bell.

In New Vegas, there is an enemy called the Y-17 trauma override harness. The suit was designed to make sure that the person inside would go back to the base he was stationed at in the event that he was unable to himself.
However this suit has some problems. It doesn't know if the user dies, and if it doesn't have a home base, it will walk forever until it's given one.

If the player has a special perk called "Wild Wasteland", they can find odd and out of place things in the game, and when fighting this enemy you will sometimes hear them say, "Hey, Who turned out the lights?"

This is a reference to the Doctor Who episode "Silence in the Library", in which the Doctor went and found some researchers who had special suits. The suits had a function in which it would keep the user alive after he died through a link called "ghost data", and could make them speak by retaining their consciousness. One of the first people who died would repeat the words, "Who turned out the lights" over and over again since the lights inside his visor were turned off.

On the eastern part of Camp Searchlight you can find a church with an accessible basement. Inside of the basement you can find, while having the Wild Wasteland trait, three Holy Hand Grenades (really called Holy Frag Grenades) that do massive damage. These grenades are a reference to Monty Python and the Holy Grail.

In Nipton, if the player has the wild wasteland perk activated, two charred skeletons can be seen with the names Owen and Beru. This is a reference to the movie Star Wars. In the movie, Luke Skywalker returns home to find his family farm on fire and the burned corpses of his aunt(Beru Lars) and uncle(Owen Lars).

A lot of the content in Fallout: New Vegas was going to be featured in the cancelled Fallout 3 game being developed by Black Isle Studios. Some of the elements are Caesar's Legion, The Burned Man, and The Big Empty among others.

At the entrance of Nipton, a man by the name of Oliver Swanick comes up to you and proclaims he won the lottery. Later, we discover that the lottery is a death sentence, and if you fail to win, you are executed. This may be a reference to a short novel "The Lottery" by Shirley Jackson, where the winner of the lottery was stoned. This is practically the same incident, just the prize for winning altered. It can also be said that both of the lotteries are well known around town.

In the game, there is a reference to the comic "Calvin and Hobbes". In the Comic, Calvin's favorite cereal is Chocolate Frosted Sugar Bombs, which is referenced with the food item, "Sugar Bombs".

With the Wild Wasteland perk, the radio host Mr. New Vegas ends his news segment with the saying "Stay classy, New Vegas." In the movie Anchorman: The Legend of Ron Burgundy, Ron Burgundy ends all his news segments with "You stay classy, San Diego."

Mr. New Vegas is voiced by Wayne Newton, who is known as Mr. Las Vegas in real life. The designers created the role for Newton "because he is Las Vegas," and that "he really brings that extra touch of Vegas class to the game."

Benny is based off of Benjamin "Bugsy" Siegel, who was an American mobster and one of the main driving forces in the development of the Las Vegas strip. There is also a striking resemblance between the two men's signature checkerboard suits.

Ulysses was originally going to be a companion, but was cut from the final version of the game and then put back in for the Lonesome Road DLC as the main antagonist.

This would have made him a Legion-sympathetic companion and would help explain Legion backstory elements, as there wasn't much Legion support from any of the other companions. He would have also reacted strongly to NCR/Legion conflict and the player's role in it, acting as a sounding board when possible.

There were originally plans for romance speech options and game endings for companions, but the idea was ultimately cancelled before any work was done on it. According to Jason Bergman (the Senior Producer for New Vegas), "Tt was clear that it wasn't going to be fun or interesting in any way. Also Avellone really hates romance in games."

One of the romance ideas that was talked about was if you romanced Cass, you were both going to get drunk and wake up married. And there was another idea where if your rep was high enough, the player would get married to their companion by the King, with him singing "Love Me Tender" a la Nicholas Cage in Wild at Heart.

Zion Canyon, from the Honest Hearts DLC, is based on Zion National Park, a favorite holiday destination of New Vegas lead designer Joshua Sawyer.

The text on Joshua Graham's pistol, A Light Shining in Darkness, is Greek. It reads "καὶ τὸ φῶς ἐν τῇ σκοτίᾳ φαίνει (kaì tò phõs én tẽ skotía phaínei)" on the right side and "καὶ ἡ σκοτία αὐτὸ οὐ κατέλαβεν (kaì é skotía aútò oú katélaben)" on the left side, which translates as "And the light shineth in darkness and the darkness comprehended it not".

New Canann, the town where Joshua Graham and Daniel hail from, was named after the land promised to Abraham and his followers in the Bible. This is likely due to the people of New Canann being Mormon.