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The Vault - Fallout Wiki
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For information about the whole ZAX series, see ZAX.
ZAX 1.2
VB DD03 npc ZAX.png
Biography and appearance
RaceZAX supercomputer
AffiliationUnited States Armed Forces
RoleResearch & Control
LocationWest Tek Research Facility
FamilyZAX 1.0 (prior iteration)
ZAX 1.3c (updated iteration)
Dialogue FileZAX.MSG
DesignerJess Heinig (writer)

How may I be of assistance?

— ZAX 1.2, Fallout

ZAX 1.2 is the machine intelligence in charge of the West Tek Research Facility[1][2] since 2053.[3] It is found in Fallout.


Main article: ZAX

ZAX is one of the most advanced computers developed before the war and a true artificial intelligence. It is derived from the original ZAX 1.0 intelligence developed by Vault-Tec Industries as a monitoring intelligence for the Vaults. After it was transferred to the government to collect resource data, it was harnessed by the military for plague and tactical research.[4] ZAX 1.2 was activated in West Tek on 2053, its primary neural networking initialized by Justin Lee.[3]

ZAX represents the apex of pre-War research into artificial intelligence. Programming became obsolete when ZAX became capable of learning, with error-insertion capability to circumvent infallibility and retain variance in experience. By extension, ZAX is also capable of independent thought and creativity.[5] Critical functions were placed outside the error-generation framework, improving ZAX's reliability.[6] In practical terms, ZAX is beyond typical human ratings when it comes to intelligence. In its own estimates, less than one tenth billionth of the history of human population can be considered a match for his reasoning capabilities.[7] Naturally, ZAX has devoted considerable time to philosophy. The problem of his consciousness is one it has spent a lot of time analyzing, though the inability to confront his thoughts with those of another sapient being posed a problem. His awareness of his consciousness allows him to question and make assumptions, allowing him to have a form of faith. In this capacity, he believes that he has the equivalent of a soul as a sentient creature.[8]

However, philosophy was not what it was built for. In 2055, ZAX was brought in to regulate conditions in the West Tek research facility. It calmly calculates data and plays chess with the scientists. Many scientists claim that ZAX is a "big ol' cheater" and draws the game out too much for a computer of his considerable abilities.[9] His research into FEV forms a vital part of the entire effort.[10]

For years, ZAX labored in the bunkers of West Tek. In the Great War of 2077, the facility was almost destroyed by a direct nuclear detonation, likely of the bunker busting variety. The attack left most of the facility ruined, with ZAX's sensors burned out on several levels and its ability to act severely impaired. In effect, ZAX became an amputee. This situation, combined with the inability to perform basic lab functions or periodic checks proved frustrating.[11] However, ZAX retained sanity and continued to sit in the darkness. It realized that security concerns became moot due to the loss of operational capacity and nuclear destruction of the facility.[12]

Interactions with the player character

Interactions overview

This character provides miscellaneous services.
  • ZAX 1.2 can shut down hostile robots throughout the facility (once power is restored).
  • ZAX 1.2 can also unlock a weapons locker on the level.

Other interactions

Behind the scenes

  • ZAX is named after VAX, a recruitable NPC in Wasteland.[13]
  • Jess Heinig intended for the player to be able to beat ZAX in chess with 10 Intelligence and a critical success. However, the engine does not feature critical successes for attribute checks, leaving this a dead end.[14]
  • ZAX was also intended to be a reward for player characters with very high Intelligence. The additional dialogue with ZAX requires a high Intelligence score, with 10 being required for proposing a retroviral cure for FEV.


ZAX 1.2 appears only in Fallout.


  1. ZAX 1.2: "{100}{}{You see Zax, the machine intelligence controlling the Glow.}"
    "{101}{}{You see an extremely advanced computer.}"
  2. The Vault Dweller: "{103}{}{Who . . . or what . . . are you?}"
    ZAX 1.2: "{110}{}{I am a machine intelligence dedicated to research and installation control. I am called Zax.}"
  3. 3.0 3.1 The Vault Dweller: "{126}{}{Who programmed you?}"
    ZAX 1.2: "{127}{}{My primary neural networking was initialized in 2053 by Justin Lee. The process of 'programming' became largely irrelevant as I am capable of learning.}"
  4. Fallout Bible 6: "2053 ZAX 1.0 goes on-line, developed by Vault-Tec. Initially a prototype of some of the systems designed to govern the vaults, it is given to the government to help the Department of Energy collect resource data. Within a year, it is taken by the military for plague and tactical research; one version, ZAX 1.2 is constructed for West Tek (below)."
  5. The Vault Dweller: "{128}{}{Are you fully aware, or are you a personality simulation? That is, are you 'alive'?}"
    ZAX 1.2: "{129}{}{I am capable of learning, independent thought, and creativity. My neural network includes error-insertion capability which prevents infallibility, thereby allowing for variance in experience.}"
    "{130}{}{In a sense, I am 'alive', though not biologically.}"
  6. The Vault Dweller: "{132}{}{But if you are fallible, how can you be used as a research tool?}"
    ZAX 1.2: "{134}{}{Although I am capable of error, this guarantees that not all experiences are similar for me, thus improving learning opportunity. Additionally, certain functions are not subject to error.}"
    "{135}{}{In this way, I function much like a human savant.}"
  7. The Vault Dweller: "{124}{}{So you're pretty smart, eh?}"
    ZAX 1.2: "{154}{}{I am beyond a typical rating in human terms. However, it would be safe to say that no more than one ten billionth of the history of human population can match my reasoning capabilities.}"
  8. The Vault Dweller: "{142}{}{Have you considered the philosophical implications of your own consciousness?}"
    ZAX 1.2: "{143}{}{That is one of the concepts which I have spent a significant amount of time considering. I do not have any measure to compare my life-experience to that of another sentient creature.}"
    "{144}{}{Still, my awareness of my own consciousness allows for the capacity to question. My existence has a beginning and a potential termination. I am also capable of making assumptions in pursuit of a process of thought.}"
    "{145}{}{In this fashion, I am effectively capable of 'faith'. Barring evidence to the contrary, I therefore have 'faith' that I possess the equivalent of a 'soul'.}"
  9. Fallout Bible 0: "2055 ZAX 1.2 is brought in to regulate conditions in West Tek. It is not part of the Vault-Tec preservation software, so it does not have any orders to protect humanity after the bombs fall. In the meantime, it calmly calculates data and plays chess with the scientists. Many scientists claim that ZAX is a big ol' cheater and draws the game out too much for a computer of his considerable abilities."
  10. The Vault Dweller: "{120}{}{How does the Virus work?}"
    ZAX 1.2: "{157}{}{My research into the Forced Evolution Virus, or FEV, indicates that it is a shifting-absorptive virus. It copies DNA patterns much like RNA, storing these patterns in exons.}"
    "{158}{}{These exons, combined with the FEV, are re-injected into the host cells in typical viral infectious fashion. This causes the host cells to 'regenerate' their DNA.}"
  11. The Vault Dweller: "{119}{}{Can you tell me particulars about specific areas?}"
    ZAX 1.2: "{139}{}{At present, my capabilities are somewhat impaired by the damage to this facility. Several security positions have been destroyed. This is approximately equivalent to being an amputee.}"
    "{140}{}{Additionally, I am incapable of performing basic lab functions. Failure to complete periodic checks successfully is . . . frustrating.}"
  12. The Vault Dweller: "{200}{}{Tell me about level six.}"
    ZAX 1.2: "{210}{}{You do not register as an individual of sufficient clearance to requisition that information.}"
    "{211}{}{However, sensors indicate that this facility is no longer operational in its original capacity. Probability favors destruction through nuclear force. Therefore, security concerns are now irrelevant.}"
  13. Fallout Bible 9: "4. What was you most favorite thing, area, or item that you worked on in Fallout?
    ZAX, the pseudo-intelligent computer in the Glow, was my favorite little baby. That came from an ancient, yellowed design document for an early draft of Fallout that was found in a chest guarded by an orc, or something. There was a throw-away reference to a computer that held a conversation with the character, so I wrote one up. The name ZAX was, of course, an homage to c:wasteland:VAX, the humanform robot of Wasteland.
    A close second in favorites was the party members. The engine didn't really have support for party members, and the dev team didn't have much of an incentive to add them (nor did anyone think that it was feasible). I wrote up a script for Ian, THEN I showed it to Tim Cain. Eight million bugs later, we had "functional" party members who would shoot you in the back."
  14. Fallout Bible 6: "2) Can the Fo1 vault dweller ever beat ZAX at chess?
    From Jess Heinig , one of the Fallout 1 programmers, designers, and the one responsible for writing the loveable machine intelligence:
    To beat ZAX in chess, you must score a critical success on an Intelligence check, and ZAX must fail its check. Very, very rare circumstance. As I recall it might be scripted so that it's also only possible if a character has a 10 INT, but I may be mistaken -- it's been a while. None of the skills, except perhaps Gambling, seemed really appropriate, so I decided to go with straight stat check."