Creating and Using Basic Portal Keys

Blank Portal Keys are crafted from a Blaze Rod and a Name Tag. You may want several.

Activating Portal Keys

A blank key cannot be used to enter a dungeon. A newly crafted key must first be used in an 'activation ritual' which will inscribe the name and location of a randomly generated dungeon onto the key. This action will require you to bring the key to a fitting location on The Overworld.

Basically, find a Stronghold, and use the key on the top of an End Portal Frame. You must aim for the black square on top.

Using Portal Keys

Hooray! This key is now your ticket to adventure! Go back to your portal frame and place the key in the keyhole. If everything is correct then a golden dungeon portal should appear. If the frame was not built correctly then the portal will shatter immediately.

Dungeon portals can be built and opened in any dimension. And when you return you'll be sent back to the block in front of the portal frame that your key was last inserted into. (Even if the portal is destroyed.)

In multiplayer this can lead to "fun" interactions. Maybe your friends find it "fun" to cover your portal in lava while you're away? Or maybe they'll steal your key and move it to a portal frame in their base, causing you to emerge there instead? Hopefully you have nice friends.

Has This Ever Happened To You?

But what if your end portal is already complete? Are all 12 eyes filled and the portal to The End is open?

No problem! After all, Eyes of Ender are known to be fragile things that break all the time. So just jam your blank key in there and use it as a 'crowbar' to pry the eye out of the frame.

The eye will break and the End Portal Frame will be empty again! This will not 'close' the portal as you can see. Furthermore if someone has griefed your end portal, perhaps with Blood Magic or a water bucket, then this technique can be used to regenerate the 3x3 portal. What a value!

Reusing Keys

Keys can only be written to once. However keys are absolutely reusable! If you find a dungeon that is worth visiting more than once then be sure to save that key somewhere in your base. Each key will always consistently take you back to the same dungeon.

By the way, you can safely rename keys on an anvil without affecting their destination. The unique coordinates for each dungeon are saved as NBT on the key itself when the key is activated and will never change.