Sentry Bot/Doom 3

"Marine, if you run across any operational Sentry Bots, use them. Those guys pack a lot of firepower."

- Sergeant Kelly

The Sentry Bot is a small, dog-sized robot, constructed by Mixom Corporation for the UAC, as well as for the Marines. It is distributed throughout Mars City in Doom 3, primarily used by Mars City Security for sentry purposes. However, there were many issues with them, as one Sentry Bot suffered from a system malfunction, causing it to unintentionally target a UAC employee, before being disabled by a nearby marine.

Most Sentry Bots end up being destroyed and dis-repaired after the invasion began, save for only a small handful of operational ones scattered throughout Mars City.

Combat characteristics
A Sentry Bot consists of a robotic "head" walking on four spider-like legs, and equipped with a small, but powerful machine gun and a flashlight. They are primarily used to escort the player to their intended location, while neutralizing any threats that get in the way.

Tactical usage
Sentry Bots make excellent allies. Their standing is about on par with the middle-tier demons such as the Revenant or Chaingun Commando. A single Sentry Bot is able to efficiently mow through groups of Z-Secs, Imps, and Cacodemons, but will be quickly overwhelmed by multiple Revenants, or by a single Hell Knight, especially in Resurrection of Evil and The Lost Mission. Some levels, however, can allow the player to access another Sentry Bot if the current one becomes disabled in combat.

Sentry Bots can harm the player with friendly fire if caught between their line of fire against an enemy. The same is true in reverse if the player carelessly engages fire on them while attacking, making them more prone to being disabled. It is advisable to be wary of your position and aiming while being escorted by a Sentry.

Sentry Bots can be found in Mars City, the Enpro Plant, and the Communications Tower. They can also be found in Mars City Service Sub-Level of the Lost Mission, and in the Erebus Monorail Station and the Phobos Complex of Resurrection of Evil.

Combat details

 * Health: 300
 * Attack Damage: 5 (machine gun)
 * Locations: Mars City, Mars City (Revisited), Enpro Plant: Energy Processing and Storage, Communications, Underground - Sector 2: Mars City Service Sub-Level, Erebus Level 6, Phobos Lab Sector 3
 * Cheat spawn: "spawn char_sentry" (does not work) / "spawn comm1_Sentry" (working)
 * Flashlight: "spawn comm1_sentry flashlight 1" (Sentry has flashlight on!)

Trivia

 * Sentry bots that are spawn using commands will only stay in one location without moving, but they will attack any enemies nearby.