This article is about the Marathon Story.

A simulacrum is a representation of something or someone. Durandal uses the word to describe the bio-android bombs manufactured by the Pfhor in the image of BOBs. They were designed and created by the Pfhor's Ministry for the Eradication Through Imitation of Hostile Species Unsuitable for Enslavement, or Phan Pfhar Sfaern-Wsawn Tshah in their native Pfhoric.[1]


A chart depicting the anatomy of a simulacrum.

Simulacrums will usually run directly towards the player on sight, shouting various phrases uncharacteristic of a normal human. When close enough (less than 3 meters,[2]) they will explode and inflict severe damage to anything nearby. Simulacrums never charge at any other allies or enemies, including each other.

Known Simulacrum Phrases:

  • "Thank God it's you!" (M1 only)
  • "I'm out of ammo!"
  • "Kill me!" (a likely reference to the film, Aliens)
  • "No! Noooooo!"
  • "Don't shoot!!"
  • "Frog blast the vent core!"
  • "I love you man!"


Simulacrum as depicted by Craig Mullins

There are other differences between human BOBs and simulacrums: apparently the manufactured BOBs have red pupils, only two toes, no genitalia, and malformed teeth, although these differences are seen only on terminal graphics, and not in-game.[3] Also, the manufactured BOBs will run directly towards the player, whereas humans tend to run erratically or towards enemies, and assimilated BOBs never fire their weapons.

Another way to tell if they are human or not is that simulacrums only wear green uniforms, but starting with Marathon 2 this is not the qualifier. Simulacrums tend to say "Thank God it's you!" in a different tone than the standard BOB voice saying "They're everywhere," so that is usually an indication. Simulacrums also bleed yellow blood when wounded.


Do you remember the Pfhor-built human simulacrums during the Tau Ceti invasion?

The elaborate Pfhor bureaucracy has a Ministry for the Eradication Through Imitation of Hostile Species Unsuitable for Enslavement, Phan Pfhar Sfaern-Wsawn Tshah, which is responsible for the design and construction of such machines.

They meticulously constructed seventeen different human body types and mixed them with sixty-one unique facial models. The resulting walking bombs were in every way indistinguishable from real humans.

Their one mistake, dressing every last one of the six thousand simulacrums in the plain green overalls of a Marathon airlock technician, had the amusing side-effect of making all the real airlock technicians wander the ship naked during the invasion.

- Durandal, Marathon 2, We're Everywhere, Terminal 1 (2nd message)


  • The word, simulacrum, is Latin for "likeness, similarity".
  • The Halo enemies, the Flood Carrier Forms, can be thought of as a successor to the simulacrum, epecially because they are composed of former Humans.


  1. We're Everywhere, first terminal, 2nd message
  2. Marathon - Level 11: Shake Before Using..., terminal 2
  3. Marathon 2: Durandal - Level 19: This Side Toward Enemy, second terminal second message