0451

The code 0451 unlocks the first locked door in Deus Ex games. The number also appears in various other manners in the Deus Ex series.

Origin
The number first appeared in the game System Shock (as 451) and its sequel System Shock 2 (as 45100) developed by. The number was initially thought to be a reference to dystopian novel , in which it represents "the temperature at which book-paper catches fire and burns". However, Warren Spector later revealed that 0451 was actually just the door code to access the Looking Glass Studios offices in Cambridge, Massachusetts. "If you've been playing a lot of Looking Glass and Ion Storm games you know that the code here is 0451, which is first used in System Shock. It showed up in Thief, it showed up in System Shock 2, it showed up in BioShock and Dishonored recently, and in both Deus Ex games. A lot of people think it was a reference to Fahrenheit 451, the Ray Bradbury book, but it was actually just the key code to get into the offices at Looking Glass in Cambridge. But it's in so many games now, it's kind of a defining thing in what we used to call 'immersive simulations.'"

- Warren Spector, director of Deus Ex and producer of System Shock

As to the purported reference to Bradbury's Fahrenheit 451, Spector subsequently stated that "the Bradbury reference is just a nice bonus". In any event, direct references to Bradbury's Fahrenheit 451 have appeared alongside appearances of "451" in Deus Ex games developed by Eidos Montréal.

The code 0451 has since appeared in numerous other games developed by former Looking Glass employees, including BioShock, Dishonored, Prey, and others.

In Deus Ex games and books

 * In Deus Ex, the code 0451 opens the comm van near the UNATCO Headquarters.
 * Deus Ex: Invisible War does not have enterable codes, but the protagonist Alex D starts in the dorm room 451 of the Seattle Tarsus Academy.
 * In Deus Ex: Human Revolution, the code 0451 opens the elevator in David Sarif's office. It is used again as the first code in The Missing Link DLC.
 * Also, a direct reference to the Fahrenheit 451 and its author Ray Bradbury is made through an announcer in the Detroit Police Station, asking for "detective Bradbury in office 451".
 * In Deus Ex: The Fall, the code 0451 opens the door to Mikhail Kontarsky's hideout in Hotel Novoe Rostov.
 * In the book Deus Ex: Black Light, Adam Jensen wakes up from coma in Facility 451 in Alaska.
 * In Deus Ex: Mankind Divided, the code 0451 unlocks the first door encountered during the Dubai mission. A Heated Combination achievement is awarded for entering the code instead of hacking the lock.
 * 0451 is the number of the United Nations resolution that ratified the creation of Task Force 29.
 * Another reference to 451 is made in a Picus TV news report that mentions a Cista Airlines 451 plane crash.
 * A direct reference to Fahrenheit 451 is made in an e-mail found in the Time Machine. The e-mail is from R. Brad Burrie and refers to a shipment of rare books on train F451.
 * In Deus Ex GO, it is the code needed to access Novak's secret lab.

In real life

 * Jonathan Jacques-Belletête, art director of Deus Ex: Human Revolution and Deus Ex: Mankind Divided once had a flight number 0451. He wrote about that on Twitter.