Sentry bot (Fallout: New Vegas)

Sentry bots are robots found in the Mojave Wasteland, the Big MT, and The Divide.

Characteristics
Much like the Fallout 3 sentry bots, those found in the Mojave wasteland boast a loadout comprising a minigun and a Gatling laser on the right arm, with a missile launcher on the left arm, complete with a high damage threshold that protects them against low damage weapons. Their head and legs take -50% and -25% damage respectively from all normal attacks. Its one flaw is the combat inhibitor mounted on the back and its slow turn rate, allowing the player to circle-strafe and destroy the inhibitor, causing it to frenzy (though it's pointless in areas without additional enemies). Pulse grenades, mines, and the pulse gun are effective countermeasures.

They are much less common in the Mojave than in the Capital Wasteland, though no less dangerous. They typically spawn in locations such as REPCONN Headquarters, Vault 11, or the Securitron vault. A special version is found at the crashed Vertibird, alongside hardened Mister Gutsies. These hardened sentry bots have 66% more health than regular sentry bots (500 vs. 300), but no damage threshold, making them more resistant to weapons that ignore it, such as pulse weapons, and more susceptible to regular weapons.

Mark series (Old World Blues)
The sentry bot mark series only appears in the Fallout: New Vegas add-on Old World Blues.

NCR sentry bot
It is similar to the military sentry bot in appearance, but is differently colored. The NCR sentry bot was originally intended to be stationed in Camp McCarran, evident in its G.E.C.K. id McCarranFieldSentryBot, but was cut from the final version of Fallout: New Vegas.

Notable sentry bots

 * RY-589 Ultimo bot

Bugs

 * The sentry bots in Big MT may become 'stuck' half-way in the ground making them impossible to attack.
 * There are several sentry bots stuck in the ground around Little Yangtze that cannot be looted, and can be walked through as if they are not a part of the landscape at all.