Type-25 Directed Energy Rifle

Were you looking for the Brute-preferred variant of the Plasma Rifle used in Halo 2 and Halo 3: ODST, the Type-51 Directed Energy Rifle/Improved, the version used in Halo: Reach, or the Type-55 Directed Energy Rifle/Advanced, the newer version of the Plasma Rifle used in Halo 4?

"You know, it looks delicate and so you feel like you need to hold it kinda gingerly—but then you see an Elite crack a Bravo Kilo's head with one—the things are built tough."

- Anonymous Serviceman

The Type-25 Directed Energy Rifle, more commonly known as the Plasma Rifle, is a Covenant infantry weapon.

Design Details
The Plasma Rifle is a Covenant, directed-energy weapon, reverse engineered from forerunner technology that uses a superheated ionized gas called Plasma, instead of projectile ammunition. The weapon has a power output of 100-150 KV @ 2~3 dA, and can fire 360 to 540 rounds per minute. Unlike the Plasma Pistol, the plasma rifle is capable of semi-automatic and full automatic fire. This is enabled by  its dual plasma collimator design. Placed atop one another, these collimators fire in a "stagger" taking the slow automatic fire of each individual collimator and combining it, this design allows a faster rate of fire and more rounds per second, which adds to the lethality of the weapon. Taking fire from the Type-25 DER can cause severe second, third, and in some cases, fourth-degree burns (a fourth-degree burn completely burns away all flesh, leaving only bone tissue). The Type-25 DER is the primary weapon of the Covenant’s officer corps, used by Elites and Brutes, although Jackals, Grunts and higher ranking Drones have been seen using this weapon, but not as common. Against UNSC infantry, the Type-25 Rifle's lethality is considerably greater than its counterpart, the Type-25 Directed Energy Pistol, due to the faster rate of fire, injuries inflicted to the victim are severe third-degree burns, with the wound being cauterized instantly upon impact. Even near misses will produce severe burns and heat trauma. Should the plasma impact an object, the impact can create fragments that may come into contact with a victim, with a crippling or lethal effect. Generally, two hits from either a Plasma Pistol or Plasma Rifle will kill a lightly-armored target. Over-extended periods of firing can overheat the weapon, causing it to become unusable for a short period of time.

Advantages
The Plasma Rifle is a close to medium range weapon, and as such can inflict very high damage at range. The Plasma Rifle can also be used at long range if the user fires slowly and aims carefully by leading the target. The rifle is extremely efficient at killing "soft" targets, while doing lethal amounts of damage to a heavily armored target. Enough infantry equipped with Type-25 Rifles can halt enemy infantry advance with its ability to deliver harassing suppressive fire; this tactic is also reflected in the Covenant's combat doctrine: destroy enemy morale with suppressive fire from distant combatants or close-quarters intimidation tactics. SPARTAN-IIs and Elites have the ability to dual-wield plasma rifles, doubling their efficiency in close to medium range combat situations. The plasma rifle's high velocity bolt coupled with its kinetic impact to a target can temporarily stun a target like a SPARTAN-II.

Disadvantages
The Plasma Rifle, when fired continuously, overheats very quickly because of the rapid cycling, loading, ignition, and release sequence of energy; to prevent the weapon from being damaged, the Type-25 DER temporarily shuts down and opens cooling vents to allow the excess heat to dissipate before the weapon reactivates. This process leaves the weapon inoperable and useless. Careless infantry who are not aware of the function of the Plasma Rifle can get themselves killed because of this. Human military experts and scientists do not understand how Covenant plasma weapons work, or how they are recharged; as such, when the battery is depleted, the rifle must be discarded or replaced. At 10% charge level, the plasma rifle will begin to misfire, this is due to the battery's inability to deliver enough energy to start and complete the ignition and release phase of operation, hampering the operator's use of the weapon.

Although the Plasma Rifle can strike a target at longer ranges, it is not suited for long range combat, due to two distinct properties of the weapons operation. The first is the rate of thermal expansion which is determined by the rate of the bloom of the bolt. The second factor is speed: the faster the bolt goes, the farther the bolt will travel before the magnetic field begins to weaken, causing the temperature of the bolt to cool before the magnetic field becomes unstable and finally dissipates. The bolt also loses velocity and kinetic impact with longer travel distance.

Halo: Combat Evolved
The Plasma Rifle in Halo: Combat Evolved is far more powerful than its Halo 2 and Halo 3 counterparts; also the weapon holds the unique ability to stun opponents that were hit by high amount of plasma rounds: this effect greatly reduces the victim's ability to move and dodge the incoming projectiles and allows the user to easily hold the opponent in the weapon's firing arc. However, the drawback was that this effect is only felt with continuous fire. While stunned, the weapon will often overheat before the opponent is killed, especially if it is an Elite or Hunter. Despite this drawback, the stun ability is a useful and potent feature in the hands of an experienced user. Beware that the Plasma Rifle decreases in accuracy while heating up. However, firing in bursts can counteract this and is much more useful over longer ranges. In the campaign, the Plasma Rifle is best used against the Sentinels and Elites. Fully charged Plasma Rifles can be obtained by killing Elite Combat Forms or killing Elites riding on Ghosts and Banshees.

Changes From Halo: Combat Evolved to Halo 2

 * The Halo 2 Plasma Rifle is not as powerful as its predecessor and lacks the ability to stun. It is also noticeably less accurate, especially at long range. These drawbacks are compensated by a higher rate of fire and the ability to dual-wield, allowing it to be paired with a wide variety of other weapons. It is best paired with an SMG or M6C Magnum.
 * The changes done to the weapon are directly related to the inclusion of dual-wielding and higher rate of fire. For purposes of balance, the Plasma Rifle, along with many other weapons from Halo: Combat Evolved, has been tweaked to better fit the new game engine. A Plasma Rifle is much more efficient at taking out the shields of an opponent compared to ballistic weaponry, but it is less efficient against flesh. This version of the Plasma Rifle behaves more as an SMG rather than a rifle.
 * The sound effects for the Plasma Rifle have been changed, to give each weapon a distinct sound to distinguish it easier.
 * A new variant, the Brute Plasma Rifles, is introduced.
 * Battery depletion rate is halved.

Changes from Halo 2 to Halo 3

 * The Plasma Rifle in Halo 3 is much more powerful than its Halo 2 counterpart, but is still weaker than the Halo: Combat Evolved Plasma Rifle. Like most of the plasma weapons featured in Halo 3, they have the same overheating rate as their predecessors.
 * The Plasma Rifle now fires as fast as the Brute Plasma Rifles in Halo 2.
 * Plasma bolts fired by the Plasma Rifle and all other plasma weapons in Halo 3 have been graphically redesigned to have a more vivid look. The bolts now seem to travel faster than from previous games, reducing the need to lead the shots at mid-to-long ranges.
 * The weapon is more accurate than from Halo 2, but still not as accurate as its Halo: Combat Evolved incarnation.
 * It takes fewer shots of constant fire for the Plasma Rifle to become very inaccurate.
 * It is considerably harder to come across the Plasma Rifle in Halo 3 campaign, because of the lack of Elites and the introduction of new Brute weapons such as the Spiker.
 * In Halo 3 multiplayer, it takes eighteen plasma bolts when not dual-wielding to kill a fully shielded opponent.
 * It has a scale-like pattern on it.

Changes from Halo 3 to Halo: Reach

 * Less streamlined appearance.
 * In Matchmaking, it is only available for use in Elite Slayer as part of the Armor Lock loadout.
 * Small aesthetic changes such as a shorter length.
 * Deeper firing sound.
 * Not dual-wieldable (restricted to AI Elites).
 * Overheats faster.
 * It now has a battery charge meter on both sides of the weapon, but since the player cannot dual-wield this is of no advantage.
 * Said battery meter is drastically different.
 * Noticeable decrease in the rate of fire.
 * The grip now has notches on the handle for the Elite's two fingers to fit.
 * The swinging melee animation, which has been used for all past Halo games, has been removed. Instead the player will either punch or melee with the butt of the gun.
 * The support rod behind the collimators is now gone.

Campaign

 * In Halo: Combat Evolved, it is good to carry the M6D pistol as a secondary weapon. Use the Plasma Rifle to take down Elite or Jackal shields, and use the pistol to secure headshots on unshielded opponents, Grunts and Hunters. However, an Assault Rifle and Shotgun works better on Flood-based levels.
 * In Halo 2, dual-wielded Plasma Rifles are extremely effective against a Hunter's back. It seems to stop and "stun" a Hunter from using its back melee on the player. This is very useful on higher difficulties.
 * On Flood-based levels in Halo 3 Campaign, dual-wielded Plasma Rifles work as well as the Brute Shot over longer ranges and pick off more distant Forms, especially Ranged Forms and Combat Forms. By zooming in, and looking at the bottom of the HUD, you will see red numbers indicating their distance - Plasma Rifles works best against hostiles within 50 meters. Opening short bursts of fire will immobilize them easily, as they flinch and cease fire when being shot.
 * You might rather use the Plasma Rifle or the Plasma Pistol on Sentinels because human weapons often take longer to kill them.

Multiplayer
In all of the Halo games, plasma-based weapons such as the Plasma rifle are the best weapons to deplete the enemy shields, especially overshielded players. Although its range limits the weapon to close-quarter and medium range firefights, if used properly a player can quickly dispose of a distant enemy. It is recommended that players use the Plasma Rifles first to eliminate the opponents' shields and finish them off with a human weapon such as the Assault rifle, Battle rifle or SMG. In Halo: Combat Evolved, the Plasma Rifle has the ability to stun opponents, enabling players to quickly incapacitate their opponents quickly with a quick melee when close-by. In Halo 2 and Halo 3, dual-wielding increases the combined rate of fire and damage.
 * In close-quarters, like all other weapons, it is preferable to just take out the opponent's energy shield with a few rounds, followed by a melee attack.
 * Like all plasma-based weaponry, it is great against shields, but it takes a slightly longer time to take down an unshielded opponent compared to ballistic weapons like the Assault Rifle.
 * In Halo 2 and Halo 3, dual-wielding in conjunction with a weapon that does high flesh damage (i.e. SMG or Mauler) can be very effective if the Plasma Rifle is first used to deplete the target's shields, followed by the next weapon used to secure the kill. Keep in mind that accuracy of both dual-wielded weapons will be reduced.

UNSC Remarks

 * “The Type-25 DER has no recoil to speak of; it tears up shields and you can shoot the thing all day long—it's on the heavy side though.”
 * “I realize that it uses a battery instead of a magazine, but nobody has figured out how to swap it or recharge it yet? Don’t we have scientists working for us or something?”
 * “It’s got no sight-line, it’s awkward to hold, and if it overheats it’ll cook the hair right off of your wrists.”
 * “You know, it looks delicate and so you feel like you need to hold it kind of gingerly—but then you see an Elite crack a Bravo Kilo's head with one—the things are built tough.”
 * “Yeah, and I’ve seen some Elites swinging two of them around like it was nothing—scary shit.”
 * "These things are huge—but I guess the Elites are, too—so it sorta makes sense."

Trivia

 * In Halo: Combat Evolved, the Plasma Rifle and the Plasma Pistol use the same sound file.
 * In Halo 2, the Brutes normally wield the Brute Plasma Rifle, except in "The Great Journey", where you find that the Brutes driving vehicles wield the normal Plasma Rifle. Also in the level "Sacred Icon" you can see that a few fallen Brutes have Plasma Rifles beside their corpses.
 * If you fire your Plasma Rifle until it overheats and melee before the animation stops it will still emit the excess plasma.
 * If your character remains idle for a minute in Halo: Combat Evolved, he'll inspect the weapon on both sides; in Halo 2 he'll open the cooling vents; in Halo 3 / Halo 3 ODST, he'll pull on the top.
 * Like most Covenant weapons, the Plasma Rifle has no sights. It appears to rely entirely on the user's HUD reticule for aiming
 * Laser Tag maker Jasman Toys produced a Plasma Rifle Laser Tag model. There is also a Plasma Pistol model, both of which use the same targeting frequency and are compatible. The Plasma Rifle has full automatic fire, but "overheats" after 20 rounds and the player must wait for it to "cool off" and close the thermal vents.
 * In Halo: Combat Evolved, the Plasma Rifle has 2 shots per 1% charge, totaling at 200 shots. In Halo 2 and 3, it has 4, totaling at 400 shots.
 * Modified Plasma Rifles appeared in Halo: The Cole Protocol. They featured ammo readouts with Arabic numerals and pop-up sights, and were sold to Humans from the Kig-Yar black markets in The Rubble. This was discovered by the rest of the Covenant and seen as heresy. The UNSC also ran into numerous occasions with innsurectionists using the very Covenant weapons that they bought against them.
 * In Halo 2, when you play as the Arbiter, if you look carefully at the Plasma Rifles your allies carry, they are in "overheat" mode.
 * In the Halo: Combat Evolved instruction booklet there is a Plasma Rifle picture over a picture of the Needler.
 * In Halo: Reach, Plasma rifles are one of the few weapons which has a reticle that never changes size.
 * In Halo: Reach, the Level Exodus does not contain a Plasma Rifle, as no Elites are encountered, and there is no Brute Plasma Rifle in Halo: Reach.
 * There is a small gauge near the end of the Plasma Rifle's top half, the gauge only appears on the Halo: Reach version of the weapon and is likely a charge indicator.
 * The Plasma Rifle does not appear in the Halo: Reach Beta.
 * Elites hold the Plasma Rifle with one hand, but they somehow can still get their left hand burned when the Plasma Rifle overheats.
 * A Plasma Rifle can give away an Active Camouflage because of the slight blue glow emitted by the weapon. The same effect happens when using an energy sword.
 * The design of the rifle recalls the TER from the television series of Stargate SG-1.
 * The Plasma Rifle is not featured in the Halo 4 gameplay, being replaced by the new Storm Rifle weapon. However, the Plasma Rifle makes a cameo appearance in the prologue in Halo 4, wielded by Sangheili Minors.

Internal

 * Type-25 Directed Energy Rifle/Jiralhanae variant
 * Type-25 Carbine
 * M7/Caseless Submachine Gun
 * Type-51 Directed Energy Rifle/Improved
 * Type-55 Directed Energy Rifle/Advanced