BL_ID (or BLID) is a unique ID for each player, which allows them to be identified, even if their in-game name changes. This ID number is used in many critical areas of the game, such as authentication, trust, and bans. Each ID is associated with a unique authentication key received when purchasing the game.

The ID's 2-99 are not in use, and IDs 0 and 1 are owned by Badspot and Kompressor, repectively. The IDs 666 and 1337 are also unused, and are often used by different Add-Ons for bricks that are created by the add-on itself and are not supposed to be tampered with by the player.

The BLID of a player is often used to determine when the player bought the game, as the IDs follow a numerical order, higher IDs being purchased later than lower ones. However, this is not always a reliable method for establishing how long a player has been playing the game, as they can own multiple keys which might have been purchased at different times.

Finding Blockland IDsEdit

Players' Blockland IDs are not visible by default. To view someone's BLID, one can follow these steps:

  1. Open the Options menu. Instructions to open the Options menu can be found here.
  2. Click on the "Advanced" tab at the top of the menu.
  3. Scroll all the way to the bottom of the Advanced tab.
  4. Just above the category called "Misc Options", there is a setting called "Show BL_IDs in player list." Make sure that this setting is enabled.
  5. Click "Done".
  6. Press F2 to open the Player List.
  7. Each player's BLID will be listed next to their name.


Should the BL_ID have its name changed while in use on a server, or should it be used at 2 different IP addresses at once, authentication fails for the user who connected first. The user is disconnected from the server with the message "Authentication Failed" or something similar, and in some rare cases gets the privileges of the ID revoked. If you experience this message, try changing your name to something else and changing it back to re-authenticate. Or if that's too technical, simply restart the game.