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FIDO is the upgraded K9000 cyberdog gun in the Fallout: New Vegas add-on Old World Blues.


Unlike the K9000 cyberdog gun, FIDO uses .44 Magnum rounds instead of .357 Magnum rounds, resulting in higher damage and a slightly higher spread. The brain case and the scope are red instead of green and the decal is changed to a bulldog. Other features of the K9000 cyberdog gun are included in FIDO.


FIDO can fire a total of about 2,495 standard rounds, the equivalent of 50 reloads, from full condition before breaking.

Ammunition typeDurability
Standard, HP & SWC249550
.44 special332967



Weapon name (current weapon is highlighted)- Weapon name (melee or unarmed)Attacks in V.A.T.S.- Attacks in V.A.T.S.
Weapon name (current weapon is highlighted)- Weapon name (gun, energy or explosive)Action point cost- Action point cost
Damage per attack (damage per projectile)- Damage per attack (damage per projectile)Damage per action point- Damage per action point
Damage per second- Damage per secondWeapon spread- Weapon spread
Area of effect damage- Area of effect damageMagazine capacity (shots per reload)- Magazine capacity (shots per reload)
Effect damage & duration- Effect damage & durationDurability (number of attacks before breaking)- Durability (number of attacks before breaking)
Bonus effects- Bonus effectsWeight- Weight
Attacks per second- Attacks per secondValue in caps- Value in caps
Critical chance % multiplier- Critical chance % multiplierValue to weight ratio- Value to weight ratio
Critical damage- Critical damageSkill required- Skill required
Critical effect damage & duration- Critical effect damage & durationStrength required- Strength required
With all mods attached- With all mods attached
Weapon name (current weapon is highlighted)Damage per attack (damage per projectile)Damage per secondAttacks per secondCritical Chance % multiplierCritical damageAttacks in V.A.T.S.Action Point costDamage per action pointWeapon spreadMagazine capacity (shots per reload)Durability (number of attacks before breaking)WeightValue in capsValue to weight ratioSkill requiredStrength required
K9000 cyberdog gun 26
K9000 cyberdog gun With all weapon mods attached 28


The schematics for FIDO are located in X-8 research center, next to the terminal in the kennels, which can be accessed after acquiring the key. The key can be found in a security room off of the front lobby of the X-13 research facility. After acquiring the schematics, taking the K9000 cyberdog gun to any workbench will allow it to be upgraded into FIDO. The process requires a Guns skill of 75.


  • FIDO is the only automatic weapon in the game to use .44 Magnum rounds.
  • The upgrade is best applied to a K9000 cyberdog gun without mods, as applying the update will eliminate all mods the gun currently has.
  • Regardless of the K9000 condition, FIDO will be at 80% durability.
  • K9000's mods cannot be equipped to FIDO.
  • As a total of two K9000s can be obtained, one can therefore obtain two FIDOs.
  • Despite being chambered in .44 Magnum, FIDO will eject bottlenecked rifle casings when fired.

Behind the scenes

The name FIDO refers to the name of a famous dog, the name of which subsequently became archetypical, meaning "faithful," from the Latin fidus.