Doom Eternal: How to Unlock Doom 1

Published on April 7, 2020

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Doom Eternal is full of secrets, from toys to collect to easter eggs to look for. One of the main places to see a load of hidden things is in the Doom Slayer’s room on the Fortress of Doom. While Doom 64 comes with the game in some versions, Doom 1 and 2 can be unlocked in game. To jump into the classic game, here’s everything you need to know about how to unlock Doom 1 in Doom Eternal.

When you go past where the Crucible Sword is kept, down the stairs on the right or left, and continue on to the door at the end of the path, you’ll get into the Doom Slayer’s bedroom.

You’ll have to wait to get access later in the game if you’ve just started it, but the room is full of the toys you’ve found while playing and some books with hidden messages too.

Interestingly, by the window at the back of the room, there’s an old PC on the right. You can interact with it by pressing R3 and two files will pop up. For Doom 1, you’ll be looking for the one on the left and it’ll say that it’s currently installing if you’re only partway through the game.

How to Unlock Doom 1 in Doom Eternal

What you need to do is collect all of the cheat codes in the game. There are 14 of them, as you might be able to guess with there being 14 parts to the install that the PC in the Doom Slayer’s room is trying to do.

Just find them all as you play through the game, or go back to levels to get them, and Doom 1 will unlock. You’ll just need to select the icon on the left and you’ll jump into the game.

Time needed: 5 days.

In short, to unlock Doom 1 in Doom Eternal

Reach the end of Level 3, where you’ll unlock assess to the Doom Slayer’s bedroom.
Collect all of the Cheat Codes in the game. There’s 14 to get.
Head to the bedroom and interact with the PC in there. Doom 1 will be the icon on the left.

That’s everything you need to know about how to unlock Doom 1 in Doom Eternal. For more tips and tricks on the game, be sure to check out our wiki guide or search for Twinfinite.