On this page of our Doom Eternal guide you will find valuable tips for people who have problems with the complexity of the game or who just like to have a little fun. We explain how to unlock cheat codes in Doom Eternal.
Guaranteeing yourself the ability to play with cheats is not easy, but using the method described below, you can also use cheats on PS4 and XONE consoles.
To use cheats, you will need floppy disks, which are one of the collection items available in the game –
Doom Eternal: How do I unlock cheat codes? – FAQ – Doom Eternal Guide

To use cheat codes, you will need floppy disks, which are one of the collection items available in the game. An example floppy is shown in the picture above. You can find information about where to find such items on the Secrets page (on the world map).
Each floppy diskette opens its own cheat code, for example, an infinite number of lives, immortality or infinite ammunition.
To use cheats, you must return to the Fortress of the Duma, which is the center of the game and which you visit between the main missions. Find the mission terminal in the fortress (Mission Choice).
Unfortunately, you cannot use cheats when you first play on a certain level. You can only use cheats when you repeat a previously completed mission.
You can activate all available cheats or only selected ones. There are 14 floppy disks with different cheats in the game world. We will post a detailed map of their location later!