The Pizza Code Mystery ARG Wiki
The Pizza is a LIE!

It has come to my attention that strange messages have been appearing throughout Black Mesa, and have been causing somewhat of a conunDrum concerning what has become known as "The Pizza Code Mystery".

I have long suspected that there was something stRange going on during the development of this facility. The unexplained disappearances, misappropriation of funds regarding cheesy oven-baked bread products and an ominous feeling that something is constantly watching this all from the shadows, Have added up to create something that needs solving, and sOlving fast.

As a result, I am offering a small reward to the first peRson that can solve this mystery and provide me with the answers I need. Together, I'm sure you caN crack this.


Welcome to the The Pizza Code Mystery ARG Wiki!

This wiki details our efforts since 2012 to solve The Pizza Code Mystery: a complex and multilayered ARG found in Black Mesa, a re-envisioning of Valve Software's seminal classic Half-Life. As of January, 2022, The Pizza Code Mystery ARG is still ongoing, with active and unsolved puzzles, and many aspects of the story and lore yet to be fully pieced together.

It is possible that some information here may be incomplete or out of date. For the latest activity and theories, join the official Crowbar Collective server on Discord (, and go to the #pizza-delivery-arg channel there. You can also check the archived forum thread for older information (formerly on

Recent News[]

March 15, 2022
The YouTube channel Noclip released a documentary on the development of Black Mesa, featuring Stormseeker as one of the developers being interviewed. Shortly after, Stormseeker posted "there are no clues in the noclip documentary" in the ARG channel on CC's Discord. During Stormseeker's interview in the documentary, his noticeboard is visible in the background, which apparently contains ARG clues.
December 23, 2021
Prof. B posted the message "helping" in the Discord chat, followed by an image showing a chessboard filled with letters.
April 26, 2021
The full version of the Xen Museum was officially released on the workshop and the incomplete leaked version removed from the game files in another update patch.
April 25, 2021
A new map named "xen_museum" was found in an update patch to Black Mesa published on April 24, 2021, on the public-beta branch. Stormseeker had previously hinted of a Xen museum when commenting on the non-existing c2a4d map.
December 23, 2020
A user named Prof. B posted a coded message in the Discord chat. In other news, the official game mapsrc folders were released.

More news >

Current Unsolved Puzzles[]

Apart from the puzzles above, there is also the task of tying everything together and working out the full story of where Dr. Horn has gone, what he has become, and how the pizzas tie into it. And there are still many unanswered questions and lingering mysteries. Below is a list of some of them:

  • The story - Some parts of the picture are known, but the entirety isn't.
  • HALOS - An entity worked on by Dr. Horn. Thought to be an AI, created in conjunction with investigations into multiplexed exotic matter based systems with the goal of creating hard-light holograms. HALOS' ultimate purpose, capabilities, and evolution are not fully known or understood.
  • 21 into 1.
  • Unsolved elements found on the "conspiracy" whiteboard.
  • The mystery of the non-working (but now evolving) gate and its unknown destination.
  • Circled letters on Xen whiteboards that spell out LOCUTS.
  • The Myons - Creatures or characters linked to both Stormseeker and Dr Horn.
  • It has been hinted that there are still secrets in the game (Black Mesa) that have not yet been found.
  • The meaning of the references to Arcadia, Paradise Lost, Dante's Inferno and "the island".


Below is a list of items that may contain additional clues in addition to the clues found in the solved puzzles. Some of them may be related to the recently solved puzzle:

Solved Puzzles[]

Recent Puzzles[]

In-Game Puzzles[]

The original puzzles that introduced the ARG.

IRC Puzzles[]

Puzzles that were given to us by Watcher on the now defunct IRC channel