Eos'Mak-pattern plasma pistol

"The Type-25 DEP is the bread and butter of Covenant small arms—almost as common as the MA5 is with the UNSC. After the Covenant Carrier jumped there were some areas of Mombasa where Plasma Pistols covered the ground like leaves—that maneuver killed a bunch of dudes on both sides."

- Unnamed UNSC Serviceman.

The Type-25 Directed Energy Pistol is a Covenant infantry firearm, carried commonly by the smaller species, such as the Unggoy, Kig-Yar, and the Yanme'e, as well as sidearms for the bigger species such as Sangheili and Jiralhanae.

Design Details
A Plasma Pistol, is a Covenant directed energy weapon that use superheated ionized gas called Plasma, instead of traditional Human ballistic ammunition. The weapon has a power output of 100-150 KV @ 2~3 dA, but, when overcharged, the power output is 1.5 MV @ 2~3 dA. The Type-25 DEP is standard-issue for lower-ranking Covenant infantry such as Grunts and Jackals, but is occasionally used by higher ranking species within the Covenant; as such it is the most commonly encountered Covenant plasma weapon. If fired quickly enough, the Plasma Pistol is capable of shooting as many rounds per second as the Plasma Rifle. Against UNSC infantry, the Type-25 Pistol's lethality to a person is extreme; 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 crippling or lethal effect. Generally two hits from either a Plasma Pistol or Plasma Rifle will kill a light, or non armored target. The Type-25 Pistol also has the ability to charge a single superheated bolt, which can instantly deplete almost any form of energy shielding, or if the overcharge bolt was to hit a flesh based target, would result in instant death. This high-powered shot makes the Plasma Pistol a formidable strategic weapon, however like its counterpart over-extended periods of fire will overheat the weapon. In the context of the Halo games, all of the plasma weapons strength and lethality, are compensated for both the sake of ESRB rating, and gameplay.

Advantages
The Plasma Pistol is a close to medium range weapon, and as such can inflict high damage at range. The Plasma Pistol can also be used at long range if the user fires slowly and aims carefully by leading the target. The pistol is extremely efficient at killing 'soft' targets, while doing lethal amounts of damage to a heavily armored target. Its overcharge ability is extremely dangerous to shielded infantry and to non-shielded infantry, because of the high amounts of energy being released, a vehicle running on either a hydrogen engine, or is lightly covered can be damaged or disabled if the bolt hits it. When compared to the Plasma Rifle, the Plasma Pistol's non-overcharged firing mode is far more accurate at medium and long ranges, although the plasma projectiles tend to arc downward a bit on long range. SPARTAN-IIs and Elites have the ability to duel-wield Plasma Rifles doubling their efficiency in close to medium range combat situations. If fired fast enough the high velocity bolts coupled with its kinetic impact to a target can temporarily stun a target like a SPARTAN-II.

Disadvantages
The Plasma Pistol when fired continuously, or an overcharged bolt is fired, overheats because of the rapid cycling, loading, ignition, and release sequence of energy. To prevent the weapon from being damaged, the Type-25 DEP temporarily shuts down and opens a heating vent to allow the excess heat to dissipate before the weapon reactivates. This process leaves the weapon temporarily inoperable and useless. Careless infantry who are not aware of the function of the Plasma Pistol 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 pistol must be discarded or replaced. At 10% charge level the Plasma Pistol 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, as such this hampers the operators use of the weapon. Continuously pressing the trigger while in overcharge mode will also deplete the energy source and if not careful can waste the weapon before firing off a round.

Although the the Plasma Pistol can strike a target at longer ranges is not suited for long range combat, due to two distinct properties of the weapon's 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.

Influences
The Plasma Pistol was inspired by the human "Zeus-class fusion pistol" from the Marathon (Video Game Series). Like the fusion pistol, the Plasma Pistol is a reasonably damaging single-shot weapon with an overcharge mode. However, the fusion pistol's overcharge was far more damaging and could kill nearly any enemy in the game, with one caveat: if the gun was left overcharged for too long, it would explode, killing the wielder.

Changes
The Plasma Pistol in Halo: Combat Evolved is far more powerful and accurate than its Halo 2 and Halo 3 counterparts, the weapon holds a unique ability to stun opponents that are hit by high velocity 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. Despite this drawback, the stun ability is a useful and potent feature in the hands of an experienced user. In the campaign, the Plasma Pistol is best used against the Sentinels and Elites, as the overcharge feature will quickly deplete the energy shield of the Elite, or destroy the Sentinel.

The offensive capabilities of the weapon have varied somewhat from game to game. For example, in Halo: Combat Evolved, the standard shots were, like the Plasma Rifle, capable of briefly stunning an enemy. This ability is absent in Halo 2 and Halo 3. Also, the standard shots are much weaker in Halo 2 and Halo 3 than in Halo: Combat Evolved. The tracking abilities of the overcharged shots have varied as well. While they have a slight homing ability in Halo and Halo 3, they are extremely difficult to dodge in Halo 2.

Changes from Halo: CE to Halo 2

 * Melee changed.
 * Overload shot trail was removed.
 * Cannot fire a standard shot as fast as the Halo: CE counterpart.
 * Overload is slower but tracks much better.
 * Overloads do not kick up as much dirt, dust, and debris as the Halo: CE counterpart.
 * Overloads do no damage to unshielded targets.
 * It is able to be dual-wielded as with many other weaponry.
 * It is noticeably weaker and almost useless (except an overload).
 * Green electricity is present between the "prongs" of the plasma pistol.
 * The main color of the pistol (Blue) has darkened greatly from Halo: CE's version.

Changes from Halo 2 to Halo 3

 * Maintaining an overload now decreases the battery.
 * Gun takes slightly longer to cool down after overheating.
 * If an overload collides with a vehicle, it is temporarily disabled and has the same effect as the Power Drain.
 * Overload doesn't take as long to achieve.
 * It only "homes in" at short range, rarely does it seek out enemies as effectively as its counterparts in Halo 2 or even Halo 1.
 * When wielding, if you look at the shadow of the gun, you can see a little "cap" on the posterior end, which is actually the overheating hologram.
 * The overcharge shot resembles the one from Halo: CE, in which it has a longer tail than the Halo 2 Plasma Pistol overcharge shot.
 * The melee action has changed through the games. In the first Halo game, the Master Chief used his right arm to punch the enemy. To do this, the Chief would hold the Plasma Pistol in his left hand which was in a supportive position underneath the weapon and do a quick swing with his right arm. Ironically, the third person model still punched with his left hand. It was the fastest melee in Halo: Combat Evolved, and comparably the strongest. In Halo 2 and Halo 3, this was changed, and the player punched with the left (free) hand, while keeping a hold on the trigger with his right. Also, the punch switches between a hook/swing and a direct punch.

Campaign

 * The Plasma Pistol is most effective in close quarters when facing Elites or Brutes, by first depleting their shield and then switching to a headshot capable weapon.
 * Going up against Elites in Halo: Combat Evolved an effective up close and personal strategy is to fire as fast as you can pull the trigger, the shots will stun the Elite long enough for you to get up close and then melee him.
 * In Two Betrayals (Level) the moment you begin switch to the Plasma Pistol and dodge right behind the glass, charge up the Pistol and aim slightly ahead of where the Sentinel is heading, if timed just right you will take down all of them and still have enough ammo left to tackle the Elites in the control room's hallway.

Multiplayer

 * In Halo: CE multiplayer the same strategy used against the Elites also applies to your enemy in multiplayer. Fire as fast as you can until you get in Melee range.
 * The Plasma Pistol has been synonymous for the Halo 2 coined term Noob Combo. By equipping the Plasma Pistol with a headshot capable weapon, using the Plasma Pistol to drain the enemy's shield and then finishing him off has worked. It is most effective in Halo 2, though overpowered. In Halo 3 it can still be accomplished, if at close range or in tight quarters.
 * In Halo 3 the Plasma Pistol is the best weapon to use when disabling enemy vehicles when a power drainer is not available, though using the Plasma Pistol against vehicles will require a great deal of luck and skill. The Banshee will prove the most difficult because of its range and fast and accurate plasma bolts. The best tactic is to hide behind cover luring the Banshee until it either attempts to splatter you or flies right past you.

UNSC Remarks

 * "The trigger is soft—no feedback—there’s no break that tells you when the overcharge is gonna kick in. First time I did it was by accident and it damn near sprained my wrist."
 * "It’s a damned ray gun—how come we don’t have ray guns?"
 * "It’s great in built-up areas and clearing buildings. Anything over a couple dozen meters though? Not so much."
 * "How the foxtrot does it track anything? Whatever—I guess that’s why I carry an MA5 instead of a TACPAD."
 * "It’s just the right size and it feels good in your hands, but give me a M7 or an MA5 any day of the week."

Trivia

 * In Halo: Combat Evolved, if you remain idle while wielding a Plasma Pistol, Master Chief will pull off the top off the pistol, showing what seems to be a power cell. In Halo 3, the same will happen if you remain idle for awhile; your character will flip it open and you will be able to see the internal mechanisms of the pistol.
 * In Halo: Combat Evolved, if you have a MadCatz controller with a turbo button, you can fire the Plasma pistol as fast as the second highest turbo setting, which is as fast as the assault rifle. However, it overheats extremely fast.
 * In Halo 3, it is the only dual-wieldable weapon that does not cause less damage per shot when dual wielded than when single wielded. (26 head/body shots single or dual wielded to kill with normal shields; as compared to the M6G that takes 5 head or 8 body single wield but 7 head or 11 body when dual wielded).
 * In Halo CE, if your Plasma Pistol is running low on energy, (less then 10%) when you fire it, then it will occasionally splutter and refuse to fire. This may be due to the fact that the power cell is unable to focus the remaining energy into a ball of plasma.
 * Dadab and Linglin are the only named Grunts who utilized the overcharge mechanism of the Plasma Pistol.
 * In Halo 3, if you look at your shadow whilst holding a plasma pistol, you may notice a "cap" like protrusion on the back of the gun. This is actually the hologram on the gun that indicates if it is overheated.
 * In the Another Day At The Beach video from the Halo 2 Multiplayer Map Pack, Gunnery Sergeant Stacker uses a Plasma Pistol to take down the shields of an Elite and a member of his ODST squad uses a Battle Rifle to kill it, effectively using the Noob Combo.
 * After killing the Prophet of Regret on Regret (Level), in Halo 2 he will drop a Plasma Pistol.
 * In Halo PC, it is possible to shoot yourself with an overcharge. Just overcharge, stand directly next to a warthog and jump in right as the pistol releases the charge. It will hit the vehicle and drain your shields.
 * The Plasma Pistol is one of the only Covenant weapons in which the melee attack is a punch instead of the melee of the entire weapon.
 * In Halo: Contact Harvest, the Unggoy Dadab makes use of the Plasma Pistol's overcharge affect as an effective source of light, whilst he is leading a group of his kind.
 * If Halo PC is booted in Safe Mode, the 'overheat hologram' will not be present.

Internal

 * Type-52 Pistol
 * M6 Series
 * Plasma Rifle