Enforcer Sentinel

Enforcers are large robotic automata designed by the Forerunners, and are only released when situations are dire, such as the events concerning the Flood in Halo 2. They are exclusive to  Halo 2.

Introduction
Enforcers are massive robotic automata that were designed to prevent mass Flood outbreaks on the Halo Rings. They are seen guarding key locations such as the entrances to the Sentinel Wall on Installation 05 and the Library. Enforcers are produced by the hovering Sentinel Production Facility.

Enforcers have two Energy Shields split in half with a hole in the middle (for their guns to fire) that protect the front side of the machine. They are armed with Pulse Beams and Missiles. They are also equipped with large claw like arms which are able to pick up and rip apart most vehicles, resulting in death of all occupants unfortunate enough to be riding in the vehicle.

Combat
The Enforcer's Energy Shields can absorb more damage than a normal Sentinel shield. The shields, which only guard the front area of the machine, are immune to ballistic weapons, such as Battle Rifle, Shotgun, and SMG fire. They are similar to the Jackal shield, but are weak against plasma weapons, and are blue in color and turn red when half depleted. Like an Elite or Spartan, its shield can be taken out with one charged Plasma Pistol shot.

The Enforcer is also very strong, capable of withstanding even two Scorpion Tank shells or two to three Wraith shots. When it appears to be lifting the player's vehicle off the ground, the driver should exit the vehicle immediately to avoid being crushed, and eventually killed.

One disadvantage of the Enforcer is that they cannot detect enemies hidden in the shadows, which can be used to a player's advantage, where if a player moves stealthily enough from one area to another, the Enforcer will continue to fire into the last known area the enemy was located in. After they have lost track of their target, they will quickly lose interest and turn their back on the enemy, giving the player an opportunity to attack from behind. Once the Enforcer has taken enough damage, its shields will drop and it will explode. After exploding, large pieces will come crashing to the ground. These pieces can hurt or even kill the player if they land on them, making it best to stay away from the Enforcer when it is destroyed.

The Enforcer's red projectiles, which appear similar to the Covenant Needlers' projectiles, are usually not a threat to players as they are very easy to dodge. The Enforcer's "Needler" shares similarities to the Spiker in Halo 3. It uses these red projectiles to fight infantry at a close to medium range. It's mortar projectiles are extremely dangerous and can quickly kill you or keep you pinned down. It will use its missiles against any vehicle it encounters; from a Ghost to a Phantom, and will occasionally use it against infantry, should they appear in large groups. The Enforcer uses its mortar projectiles as medium to long range weapons. The Sentinel Enforcers also use both their Needlers and missiles against the player when on foot. They tend to fire their weapons in an order, going from their Needlers to their missiles if unsuccessful with the primary weapon, then back to the the Needlers. It will continue this until the player is killed or the Enforcer has been destroyed.

If you can shoot off its small Needler shooting arms, and the small pair of missile launchers on its back, it will start to fire an invisible Sentinel Beam. Although invisible, the beam causes visible damage to walls. The sparks emitted from the weapon show that the beam is a Blue Sentinel Beam, similar to the beam a Sentinel Major uses. (It is somewhat hard to do this, so it is not advisable, but, you can try it, making sure not to kill the Enforcer in the process.)

They were only observed on Installation 05 fighting the local Flood infestation on the levels Sacred Icon and Quarantine Zone. They were not seen in Halo or Halo 3, most likely because the situations involving the Flood on Installation 04 wasn't as serious as that on Installation 05 and Installation 00 was never expected to have an outbreak.

Weapons
The Enforcers have more devastating weaponry than the lesser Sentinels. Its main weapon is the Heavy Needler, which is more powerful than an ordinary Needler and the projectiles appear red instead of the of the Covenant-made Needler, whose rounds are purple. These "crystalline guns" were planned by Bungie to be another Sentinel weapon to be usable by the player. For reasons left only to Bungie, this weapon was not in the game, but the Enforcer's weapon is most likely the same gun. There was a glitch, however, that gave one Sentinel, called the Needler Sentinel, the weapon. The secondary weapon is a mortar/missile launcher which is related to the Wraith's but a less powerful version and appears like a flare when fired through the air due to it's yellow/gold bright appearance. Its last weapon is its robotic "arms" which clamp onto vehicles and crush it, but the Enforcer can only do this if the vehicle is directly under it.

The Enforcer on the opening cut scene of Sacred Icon has no shields, though it is most likely hadn't been activated.

Tactics
First, this varies with the situation: are you facing the Enforcer in the level Sacred Icon (close quarters, cover), Or are you in a vehicle, with heavy firepower but limited maneuverability (Quarantine Zone). For close combat in the level Sacred Icon, simply leap below it so that it can't position/fire on you. From there, you should shoot off the "legs" on each corner, making it easier to destroy. Finally, simply bombard it with sticky grenades; it should die after 2-3 on Heroic. For vehicular combat (preferably the Scorpion), you can easily blast the shielding in front of it off (one shot per half). Then, you can destroy it with one more blast. For Wraiths, repeat, but take into consideration gravity. Spectres just require patience and non-stop shooting to work. In the event you don't have a vehicle, do not stay still. You will be gunned down if you do.

The Flood Juggernaut may have been designed to destroy the Enforcers that were out of the reach of the Flood. This is, however, just speculation.

It is possible to surf these Enforcers, sort of like surfing a Sentinel. All you simply have to do is jump on top of it. Note that this is very hard to do. Also, while you are on top of an Enforcer it will not be able to attack the enemies, as it will identify you as the enemy, and focus on you, making the Enforcer useless.

Trivia

 * Enforcer's front shields form a visible and viable Marathon style logo.
 * The Enforcer looks very similar to the machines seen building in the comic titled Halo 3: The Cradle of Life.
 * A misprint in the Halo 2: The Official Game Guide made by Piggyback and Prima Games, mistakenly called the Enforcer a "Sentinel Major", causing a debate that can be viewed on this page's talk page.
 * Enforcers only appear in Halo 2 in the levels Sacred Icon and Quarantine Zone.
 * For some unknown reason, 343 Guilty Spark didn't feel it was necessary to release the Enforcers on Installation 04. However, this may be because Enforcers weren't available at the time Installation 04 was built and were only used from Installation 05 onwards.
 * It is a wonder that no Enforcers were sent to combat the Flood on the Ark, because an entire army of Flood crashed there and only Sentinels were seen fighting. It is speculated that the Forerunners never thought that the Flood would land on the Ark and didn't include any Enforcer production facilities.
 * For some reason, Enforcers weren't used on Installation 04 II. This may be because the Flood outbreak was too sudden, or because the Installation was new.
 * If the Enforcer is examined in the map files from Halo 2 (using a modding tool), it will be described as a vehicle and not as a playable character (like the Arbiter or Elites). It also sometimes drops two Plasma Grenades when it is destroyed. It is unknown what character is able to control the Enforcer.
 * They are last seen in Quarantine Zone. Presumably, Bungie intended them to be present in halo 3, although it's just a speculation.
 * When Enforcers pick up vehicles using it's two grappling arms, it will automatically kill it even when you're equipped with an oversheild.

Related Links

 * Sentinel
 * Sentinel Major
 * Constructor
 * Sentinel Production Facility
 * Needler Sentinel
 * Pulse Beams