Mission 13 in Call of Duty: Modern Warfare has a quick, easily missable reference to old-school immersive sims like Deus Ex and BioShock. And while it sounds like a callback to Ray Bradbury’s classic sci-fi novel about information control, it’s actually a reference to Looking Glass Studios.
As you follow Captain Price through the darkened manor in the Modern Warfare mission ‘Going Dark,’ you’ll eventually come to a door in a hallway.
You’ll approach the door and enter the passcode, which is 451.
Innocuous, perhaps? But given the thousand possible three-digit codes you could input, it would be a pretty massive coincidence to happen upon the same numbers used for passcodes in a number of important games that have come before.
‘451’ began showing up in games with Looking Glass Studios’ System Shock, where it appears – as it does in Modern Warfare – as a passcode for a door. It would be used again in System Shock 2, appearing in that game as 45100, and then in the original Deus Ex, as the passcode to the first locked door (0451). The code has also showed up in Thief, BioShock, and Dishonored.
GameSpot’s Mike Mahardy captured footage of the code as it appears in Going Dark:
I really enjoyed the Looking Glass Studios reference in Modern Warfare's "Going Dark" mission: pic.twitter.com/PhKwsidp0A
— Mike Mahardy (@mmahardy) October 25, 2019
The easy jump to make is to assume that ‘451’ is a reference to Ray Bradbury’s landmark dystopian sci-fi novel Fahrenheit 451, which is the temperature at which book paper combusts. But it turns out, the explanation is a bit more mundane: as former Looking Glass developer Warren Spector (a guy who went on to help create Deus Ex) has explained, 451 was really the keycode to get into the Looking Glass offices in Cambridge, Massachusetts.
You can read our Call of Duty: Modern Warfare review if you want to get a sense of what kind of game it is, and it’s probably fair to say that calling it an ‘immersive sim’ is a bit of a stretch, what with its emphasis on guns and killstreaks. But it’s still pretty cool to see it tipping the old boonie cap to gaming’s godfathers.