Deus Ex: Mankind Divided - 12 Easter Eggs, Secrets & References You Must Find

10. Code '0451' - Deus Ex

Longtime Deus Ex fans will already know the code, 0451, as it was used to unlock an armory on Liberty Island in the original game. Since then, it's gone on to feature in a number of iconic titles, becoming something of an in-joke between various developers in the games industry.

An excerpt from Urban Dictionary states:

It is a reference to the book Fahrenheit 451. The code for the first door in System Shock was 451, a System Shock 2 door had 45100 as a code, and Bioshock had a room that required the code 0451 to enter.

To get a secret achievement in Mankind Divided, simply replicate entering 0451 into the first keypad you come across, and 'A Heated Combination' will pop immediately after.