Sentinel Beams

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

Introduction

The Sentinel Beam is a basic and effective anti-Flood Forerunner weapon, that is an integral part of Sentinels, who use it to control the massive 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 the 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 (this is common for many of the Covenant weapons). 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 Installations; 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 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.