The Pizza Code MysteryEdit


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.


This wiki details our efforts since 2012 to solve The Pizza Code Mystery: an ARG found in Black Mesa, a re-envisioning of Valve Software's seminal classic Half-Life. As of August 14, 2019 the Pizza Code Mystery is on the verge of being solved as the notoriously difficult gateway puzzle has now finally been solved. With the recent release of the Xen/Gonarch beta, the ARG has entered a new phase, seeing as the puppetmaster has indicated that the conclusion to the ARG is now in-game.

It is possible that some information here may be incomplete or out of date. For the latest activity and theories check the forum thread. You can also join the discussion in the #pizza-delivery channel on the official Crowbar Collective Discord server:

Current Unsolved PuzzlesEdit

"Imagine making a discovery so great and disturbing, it turns you mad. Mad enough to think beyond perception."

The great mysteries.

  • The story - Some parts of the picture are known, but the entirety isn't.
    • Why was Dr Horn so obsessed with pizzas?
    • Why did he fall out with his colleagues?
    • What was he working on?
    • What did he discover in Xen?
    • What happened to him, and where did he go?
  • HALOS - An unknown entity worked on by Dr. Horn. Thought to be an AI, something involving holograms, a combination of the aforementioned, or something else entirely.
  • 21 into 1
  • The Myons

Clues Edit

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 Edit

In-Game Puzzles Edit

The original puzzles that introduced the ARG.

IRC Puzzles Edit

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



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