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"Oh no, I'm one of the bad ones aren't I?"
―Defective Turret[src]

Defective Turrets are damaged, unfinished, or faultily assembled Aperture Science Sentry Turrets seen and used in the Enrichment Center during the events of Portal 2.


Defective Turrets lack the outer white shell of normal turrets, and their insides are visible. Additionally, their laser guide is off or broken, and their dialogue indicates they are blind, though they seem to notice Chell regardless. They do not have any ammunition, and will merely make a clicking sound when attempting to fire. After a while, they bizarrely catch on fire and explode. Some even appear to have been assembled sideways or are still in their boxes.

Unlike the standard turrets, which speak in a friendly, soft-spoken and forgiving manner; the defective turrets speak in a more comedic, snarky and sarcastic way. They also seem to have a larger vocabulary, rather than having the repeating, predefined lines of the normal turrets. They speak in a masculine voice with a Brooklyn accent, rather than the childish feminine ones like the rest of the turrets. Their voices also seem to have less of a robotic edge than the standard turrets.

In Chapter 5 of Portal 2, Chell sabotages the Aperture Science turret assembly lines by replacing the template turret with a defective one, causing all the fully functional turrets to be thrown out. When GLaDOS attempts to surround Chell with turrets, they appear instead and do nothing, only to explode after a little while. This does not prevent fully-functional turrets from appearing later.

Wheatley later repeats this error when he plans a perfectly good ambush for Chell, but uses defective turrets instead of working ones, despite knowing of Chell's sabotage (although he may have decided to let the system choose randomly to determine which ones were functioning, as mentioned before, explaining why he made this obvious mistake). They simply stand around idle while Wheatley repeatedly asks Chell whether she is dead or not.

They will sometimes ask other turrets for bullets, try to speak in a higher voice to imitate non-defective ones, and humorously shout "Blam! Blam! Blam! I'm not defective!" in a vain attempt to not get tossed out. Certain defective turrets are in boxes. They do not shoot and blow up near instantly, as seen when Chell approaches GLaDOS in a mobile relaxation vault in Portal 2.


  • Turret backwards

    Another type of defective Turret.

    These are not to be confused with the Oracle turret, which is fully assembled but says different lines in a different voice, and does not attack, nor will it attempt to attack.
  • If the player grabs one before moving the template turret and switches them instantaneously, the template turret exploding will cause the defective turret to become slightly misaligned. Despite this, the system still functions correctly.
  • Strangely, there seem to be many exact copies of the defective turret as many of them pass through without getting discarded.
  • The turrets appearing in Course 5 of the Cooperative Testing Initiative look like defective turrets but otherwise act like regular ones.
  • Hacking a functioning turret into the game and placing it in the Master Turret Booth will cause it to change its model to a defective turret.[1]
  • If the player brings two defective turrets into the turret control room before replacing the template, then they can take one of the defective turrets with them. However, due to the Source engine, the turret will despawn when they hit the loading screen to go to the Neurotoxin generator. This is one of the few cases in the game where the player can make a forced despawn of an object happen, as usually, Material emancipation grills would destroy any objects immediately before a transition point.
  • It seems there can only be up to 4 defective turrets on the catwalks in the Turret Manufacturing plant. Any more and the turrets start exploding in the order they were caught with every additional turret.
  • In the end of the Co-op campaign, the turret guarding the vault uses neither the normal turret or defective turret dialogues. Instead, it blurts out "But I need to protect the Humans!" in an entirely different voice just before opening fire.
  • If the player manages to enter the "Oracle" turret into the template area through console commands after the functioning one has been removed, the Oracle turret will instantaneously become a defective turret upon contact of the template area.
  • There are several Turrets in Portal (during Chell's escape) that look like regular Turrets, but act like Defective ones and do not function.
  • The defective turret appears in the co-op main story credits.
  • If the player looks closer to the white rectangle on the top they will see the word "A01" typed on it.



See also[]

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