Now if you’ve just started Dead Cells, you won’t be able to access the Cavern just yet. You first have to defeat The Hand Of The King, who is the final boss in your first full run of the game. Once you’ve beaten him, you’ll unlock an upgrade called the Homunculus Rune. This will allow you to detach your head from your body and roll it around in front of you. You can also jump while you’re just a head, which will be important in a moment.

After you’ve done this, the large door that you would normally walk past during the start of your run will be smashed open leaving a giant, flaming hole in the wall that you can enter. Inside you’ll find a pool of lava, some locked doors, and an item that’s out of reach. Behind these doors are switches that will unlock them, but you can’t reach them with your head and body intact.

To unlock these doors, you need to time a jump with your separated head so it can go under the doors and up through the wooden platform. Stand close to the edge, fling your head forward, and jump just before it hits the lava so it can stick to the wall of this middle platform. Then travel upwards and your head will roll over the switches to open these doors. Now you can reattach your head and jump across.

At the end of this room is where you’ll find the Cavern Key. Now the only question is what exactly do you do with this key?

To reach the Cavern, you need to make it to the fifth level of your run. Once you’re at this point, you have to be able to go to the Graveyard. If you don’t have the option to go there, then you’ll have to try to get inside the Cavern on a different run.

To get to the Graveyard, go to the Toxic Sewers as your first biome beyond the starting area. From there, find your way to the Ancient Sewers, then enter the Insufferable Crypt and defeat a boss named Conjunctivius. After that, you should have access to the Graveyard.

Near the beginning of the Graveyard, you'll see a locked area that requires you to find the Graveyard Key to progress. Head across the level until you find that key and then return to the locked door. Use the Graveyard Key and continue on until you see a huge stone monument covered in crystals that looks like this.


As you can see, there’s a symbol here that matches the shape of the Cavern Key. Insert it and you’ll open up the passageway that will allow you to enter the Cavern.

You’ll now have permanent access to the Cavern biome. Here you can fight off tough enemies, find new blueprints, and eventually discover the Guardian’s Haven where you can battle a boss known as The Giant. Have fun and try not to lose your head!