Sentinel beam

The Sentinel Beam is a Forerunner plasma based Directed Energy weapon, and is the primary weapon of Forerunner constructs, specifically Sentinels. This is particularly effective against the Flood and energy shields.

Introduction
The Sentinel Beam is a basic and effective anti-Flood Forerunner-built weapon that is an integral part of Sentinels, who use it to control outbreaks of the Flood. However, it was designed to only fight small outbreaks. It is projected as a yellow-orange or blue beam of energy that can efficiently cut through hordes of Flood, Infection Forms in particular, that the Sentinels have to deal with when an outbreak occurs. The blue Sentinel Beam is a stronger, more efficient version of the common yellow-orange Sentinel Beam, but it overheats more quickly and its charge depletes faster. The blue Sentinel Beam is used by Sentinel Majors.

Like the Energy Sword and Fuel Rod Gun, the Sentinel Beam is not player-usable in Halo: Combat Evolved, but it is usable in Halo 2 and Halo 3. The more powerful blue version of the beam is only available in Halo 2 campaign, not in multiplayer.

The Sentinel Beam runs on a non-rechargeable battery with a maximum charge of 100% that runs out very quickly, so this means that when depleted you will have to find a new weapon or a new Sentinel Beam. Like the Covenant's Plasma-based arsenal, it can temporarily overheat if 20% of the battery is used up in one continuous stream. It is effective against the Flood and Sentinels, and is able to quickly deplete shields like Plasma weapons, though it does less physical damage. It also vents excess heat extremely quickly, to counter the effects of the fast overheat rate of the weapon.

An Easter Egg shows a dual wield version of the Sentinel Beam in Halo 2.

Continuous contact from a Sentinel Beam can be devastating against any opponent, especially in Halo 3.

The beams used by the Sentinels at Onyx were a golden color, an odd exception to the usual rule of blue beams being the most powerful. Although this variation of the weapon took significantly longer to charge, it is thought to have been capable of destroying a fully shielded Spartan, and gained exponential increases in power when multiple Sentinels worked together, to the point where it could be used to destroy entire fleets of Covenant Cruisers. It may be worth noting that there were some other differences between the Sentinels of Onyx and the ones that appear on the Halo Array; these were pointed out by Dr. Halsey. These are listed under Onyx Sentinel. Also, the Sentinels on Onyx are of a different design to the ones on the Halo rings, as these were meant to guard a Shield World, not Flood containment facilities.

Since Sentinels were created over a millennium ago, it is believed they have unlimited battery (or an integrated battery on the Sentinel), although when you destroy Sentinels they show a battery of under 100. Sentinel Beams have unlimited range, but is equipped with a scope on the Sentinel's eyes rather than on the weapon, since Sentinels can't actually "hold" weapons.

In the Halo 2 campaign, the Sentinel Beam is a deadly, all-around good weapon. It is highly effective when used to strip shields of an Elite. It possesses a decent rate of fire, amazing accuracy & range, and great damage against both shielded and unshielded opponents, though short bursts of it cause little damage, sustained beam assaults are withering. The beam's targeting reticule is also reasonably centered, providing a better aim. The weapon's melee attack is about as strong as that of the Rocket Launcher's, and is likewise considerably slow. Two variants of the Sentinel Beam are seen in the campaign: the standard yellow-orange one in the silver housing, and the more powerful blue beam, which is encased in a gold housing. While the blue version is more powerful, it is also quite rare and will overheat faster than the standard version of the weapon.

The beam makes another appearance in Halo 3, with a few visual upgrades and several technical fixes. Unlike its Halo 2 counterpart, the weapon now has virtually infinite range and fires a much stronger beam that, if held consistently on an enemy, can destroy them within a few seconds. It is, obviously enough, extremely effective when used against Flood, and will cut down any form, including the vaunted Pure Forms, if aimed properly. The beam does not spawn on any multiplayer maps using the standard weapons settings, and players cannot spawn with them in any game type, custom or otherwise. However, the weapon must be added to a map through the Forge editor for use in multiplayer. Combat-wise, in Halo 3, this weapon is a very useful weapon in the right situation, the ammunition is depleted quickly, but it is a powerful tool in combat, especially if played on Infection, with infinite ammo enabled.

Also worth noting is the version of the beam that the Monitor 343 Guilty Spark makes use of. In Halo 3, the construct uses the integrated weapon to destroy a Flood Combat Form, mortally wound Sergeant Avery Johnson and fight off the Master Chief and the Arbiter. The beam he fires is more powerful than and twice as thick as the usual Sentinel Beam, and is bright red in color rather than orange.

Appearances
This weapon first appears in Halo: Combat Evolved, though like the Energy Sword and the Fuel Rod Gun, the player cannot wield it.

In Halo 2, it first appears on The Arbiter, where Heretic Elites used it as a weapon to attempt to stop the Arbiter and his allies from eradicating the Heretic force, in the Gas Mine. Flood Elite Combat Forms then used it on The Oracle, since almost all of the Elite forms were once Heretic Elites. Many of these weapons appear on Sacred Icon and Quarantine Zone, where the stronger blue beam versions were available from the many destroyed Sentinel Majors. It lasted longer than the one in Halo 3.

In Halo 3, It first appears on The Ark, where it can be gained by picking one of the Sentinels being destroyed (by you, although they may attack you if you destroy too many, or the Covenant Loyalists) patrolling the area. Then it was seen on The Covenant, where some Sentinels were tasked to aid the Arbiter and Master Chief in their escape from the Flood in the Ark's Citadel. When Master Chief, the Arbiter and Johnson arrive on the new Installation 04 (II), they had to clear the Flood blocking their way to the Control Room with the assistance of Sentinels. When one of the Sentinels is destroyed, the Sentinel Beam will remain intact. When the monitor 343 Guilty Spark was destroyed, and the Halo ring activated, Sentinels turned on the escaping Spartan and the Arbiter, which caused several casualties and left their Beam weapons collectible to them. The energy of this weapon was drained when using rather than the one in Halo 2.

Character Compatibility

 * Elites (Halo 2 and Halo 3)
 * Spartan IIs (Halo 2 and Halo 3)
 * Sentinels
 * Monitors

Multi-player
The Sentinel Beam is quite rare in multiplayer games, and if available, it can be a powerful weapon in the hands of experts. In Halo 2, the Sentinel Beam is useful, but in Halo 3 it is one of the best weapons in the game. On many Infection game types, when Zombies have instant death, the Sentinel Beam is very powerful, allowing a player to sweep an area at any range, killing all foes in the immediate area.

Halo: CE

 * The Sentinel Beam is only available for use if you bump-possess a Sentinel in Custom Edition, carry out a certain order of steps or simply modify the desired level so that you start with a Sentinel Beam, or so that you start as a Sentinel. The beam never runs out, but it is relatively ineffective against other players. Otherwise, this weapon is not seen at all with anything other than the Sentinels in Campaign.

Halo 2

 * In Halo 2 Multi-player, the Sentinel Beam appears as a default weapon in the bases on Backwash and on Desolation.
 * The weapon can actually make it harder for enemy players to see if it is aimed at their head, but should only be done at close to medium range.
 * This is best used in a small map like Warlock. Also good for Headlong as long as you have other more powerful weapons with you.
 * If the Sentinel Beam is the only weapon you have, conserve ammo and rely on melee as much as possible. It has a greatly effective and quick melee. Only fire the weapon when your target is far away, because ammo goes fast. Melee in close quarters, and avoid deadly crossfire. Replace as often as possible.
 * If you have other weapons on the map, use those. The Sentinel Beam is effective, but hard to aim. Only use it if you have advantages over other players such as better aim, etc.
 * A Sentinel Beam is useful against flesh, so a grenade to take down the opponent's shields followed by a burst from the Sentinel Beam can quickly kill an opponent.
 * A widely refuted myth about this weapon is that it can score head shots. This is partially true. Like the Magnum, Battle Rifle, Covenant Carbine, Sniper Rifle, and Beam Rifle, it can get head shots, but only if you are already aiming at the head when you start shooting, i.e., it will not work if you sweep the beam to the target's head.
 * The Sentinel Beam is accurate at any distance.
 * Ironically, it is a very good weapon against Sentinels.
 * On the level "Quarantine Zone" you can, at start, give two of your Elite allies an sentinel beam each, and have them board the riding seats of your Spectre. Since NPCs can't run out of ammo, they make excellent weaponry. Sadly, further in the mission, if you manage to keep both Elites and Spectre intact to that point, you have to leave the Spectre.

Halo 3

 * During a game of Infection on Halo 3 Multiplayer, the Sentinel Beam is an effective way to rid yourself of chasing Zombie forces, but take care as to where you aim, since the beam is easy to spot and is likely to give your position away if the shot goes astray, this will without a doubt, get you chased by more Zombie forces.
 * When loading up vehicles, a Sentinel Beam in the passenger seat is an incredibly deadly tool. The most flexible location is in the back seat of a Mongoose, although the passenger seat of a Warthog or Prowler is also useful and advantageous to the match. The advantage of vehicle bound Sentinel Beams are that it can 'clothesline' foes.
 * Even though it is a headshot weapon, try aiming it at the stomach area for better accuracy, as the weapon is powerful enough to not need a headshot.
 * Steady shots can make the Sentinel Beam a great anti-sniper weapon. Fire at the sniper and then sweep the area. You will eventually meet your target, and they will have a difficult time evading the beam.
 * The Sentinel Beam has an extremely large power consumption rate, about 5% per second, so always carry a backup weapon and try to save the Beam for emergencies.
 * The Sentinel Beam is also very useful for taking down the Brute's Armor quickly and effectively.
 * The Sentinel Beam is also great for taking down Jackals and their shields as well as Grunts' armor, but it may overheat which leaves you a sitting duck for attacks against you.
 * The Sentinel Beam is great against the Flood, as Infection Forms will burst if they are even caught in the beam; Human Flood forms will die instantly, Elite and Brute forms may take longer to kill. Aim for the Infection Form embedded in their chest and you'll kill it. Pure Forms are tougher, but Stalkers and Ranged Forms will die by the time it overheats. Tank Forms however, will take two long blasts to take down from the stomach or for a possibly instant kill, aim for the mouth.
 * There is no playlist in matchmaking at this time where a Sentinel beam is present and usable, probably because of the power of the weapon.
 * This can sweep up Brutes without their power armor in seconds.
 * If you encounter a wraith, aim at the gunner with the sentinel beam. Sustain your fire, and you'll kill the brute gunner. It'll overheat, but wraith mortars are easier dodged than plasma cannon shots.

Trivia

 * This is the only usable Forerunner weapon in the trilogy, other than the Major Sentinel's beam.
 * Even though the beam looks as it goes on forever, it doesn’t. If you stand on top of the building near the back alley with the Warthogs in Headlong, you can shoot towards the bridge across the map and a second player can see that the beam ends.
 * It is currently not available by default in any known Halo 3 multiplayer map. It is only available in Forge, and Custom Games.
 * The Automated Turret uses a similar beam to that of the Sentinel Major from Halo 2.
 * In Halo 2, there is a lone Sentinel that fires Needler rounds and drops a Needler when killed. This was meant to be a test when Bungie was experimenting with different weapons for the Sentinels. None of these new weapons made it into the final version of the game, but the lone Needler Sentinel was not deleted from the final product.
 * In Halo 2, when a Sentinel Major's Sentinel Beam is dropped, it has the steel color of a Minor's beam, but when picked up is colored gold like a Sentinel Major's beam, denoting an error on Bungie's behalf.
 * The Sentinels on Onyx have beams with temperatures as high as 15,000 Kelvin
 * Some have speculated that the Spartan Laser was based on the Sentinel Beam. This is, if unlikely, certainly possible as Humans were alleged to have discovered Forerunner structures before meeting the Covenant.
 * Despite the fact that it has no scope, the Sentinel Beam can also be treated as a sniper weapon, due to the extremely long range and accuracy.
 * A Sentinel Beam can easily drain a player's shields on multiplayer, even with overshields on. A player can be killed in just a few seconds of direct fire.
 * The only enemies that use Sentinel Beams besides the Sentinels are Heretic Elites and their infected counterpart in Halo 2.
 * Spartans and Elites hold the Sentinel Beam like a Support Weapon such as a turret or a Flamethrower.
 * The Sentinel Beam is used as "cutting laser" and a holy beam to end the Preceptor's power in the popular Halo Machinima The Codex.
 * The Sentinel Beam's beam appears in orange and light blue colors. 343 Guilty Spark uses a much stronger and more powerful red colored Sentinel Beam.
 * When a passenger is in a ground UNSC vehicle, the weapon is held with one hand, giving the appearance of the beam being shot from the Passengers hand, not the Sentinel Beam.
 * In Halo: Combat Evolved, this weapon was not able to be wielded. When a Sentinel was destroyed, the weapon was either destroyed with the body, or simply too attached to be removed.
 * When the popular Machinima Red vs. Blue first began utilizing Halo 2, the players used as camera men used the Sentinel Beam to film as the makers of the show felt that it took up the least amount of room on the screen.
 * The Sentinel Beam is extremely powerful against Flood; if the player concentrates a shot for a few seconds it will kill most Flood Forms.
 * Forerunners referred to the Sentinels and their beams as "our very basic countermeasures".
 * The Monitor's Sentinel Beam seems to be a crossing between a Spartan Laser and a Sentinel Beam.
 * In Halo 2, you can hold a Sentinel Beam as primary weapon and a Major Sentinel Beam as a secondary weapon.
 * Quarantine Zone and Sacred Icon are the only levels in which you can get the Major Sentinel Beam.
 * There are only 7 levels in the Halo Trilogy where you can get the Sentinel Beam.
 * The Sentinel beam is strong enough to knock around the bodies of Grunts, Jackals and Drones if hit in Halo 2.
 * If you disarm an Enforcer by shooting its weapons off, its last resort weapon is an invisible sentinel beam.
 * Halo 2 is the only Halo game with a Sentinel Major beam.
 * On the Halo 2 level The Arbiter, if you look along the tunnel, you will see a Heretic Grunt sleeping with a Sentinel Beam.
 * It is possible to "rapid melee" with a Sentinel Beam like previously allowed with weapons in Halo 2 by tapping the crouch button and the melee button. It is unknown why this is possible. The Sentinel Beam and the Gravity Hammer are the only weapons currently known to have the ability to rapid melee in Halo 3 but, this is probably an overlooked mistake by Bungie since "rapid meleeing" was exclusive to Halo 2.
 * In Halo 2, if you give an Elite a Sentinel Beam, he will hold it with his left hand over the weapon and will have his hand bent awkwardly.
 * In Halo: CE if you bumb-possess a Sentinel in Developer Mode, you can pick up Assault Rifles and use them, as a Sentinel. This is the only other weapon a Sentinel can use, the other being its beam.
 * If you bump-possess a Sentinel in Halo: CE, using its beam on another Sentinel will not hurt it, but it will lower its shield, that's if it has one.
 * There are only two weapons that a sentinel can use (besides the sentinel beam/major sentinel beam) in Halo Combat Evolved; the assault rifle and the deleted gravity rifle, which still exists in the game's code.

Related Pages

 * Sentinels
 * Sentinel Major