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 species.

Design Details
The Plasma Pistol, like all energy based projectile weapons used by the Covenant, is a firearm that fires bolts of superheated ionized gas known as Plasma, instead of traditional Human ballistic ammunition. The power output is, like the Plasma Rifle, 100-150 Kv @ 2~3 dA, but, when overcharged, the power output is 1.5 Mv @ 2~3 dA. Throughout the Human-Covenant war, the Type-25 DEP was the most widely encountered weapon, and for good reason, as it proved most effective against human forces. The Type-25 DEP was standard-issue for lower-ranking Covenant infantry such as Grunts and Jackals, but was occasionally used by higher ranking species within the Covenant. If fired quickly enough, the Plasma Pistol is capable of shooting as many rounds per second as the Plasma Rifle. Against UNSC infantry and human targets, the Type 25 DEP'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. Generally two hits from either a Plasma Pistol or Plasma Rifle will kill lightly, or non-armored targets. The Type-25 Plasma 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. 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.

In Halo: Combat Evolved, its standard fire depletes 1% of its battery for every three shots, while one overcharge shot will deplete 11% of its battery. In Halo 2, it averages 5 standard shots for every 2% of its battery, while charged shots deplete 15% of the battery. In Halo 3, the battery continually depletes if the trigger is held down for an overcharged shot, and uses 10% upon firing.

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 1 and Halo 3, they are extremely difficult to dodge in Halo 2.

Advantages
The Plasma Pistol is one of the most versatile weapons in the Halo Mythology. Its ability to instantly and completely deplete most shielding regardless of strength makes it a very valuable weapon in Multiplayer, and even more in Campaign against many shielded enemies with armor, especially Elites, Jackals and Brutes with the new found Power Armor. On Legendary mode in the campaign, the Plasma Pistol is undoubtedly the most effective weapon against enemies, due to the fact that it can lower their shields, however the weapon is most effective when used in conjunction with other weapons, particularly those capable of headshots, i.e. the Battle Rifle, Covenant Carbine, or any M6 series handgun. In Halo 3 the Plasma Pistol has the ability to "freeze" vehicles, this new feature can allow the player to temporary disable the vehicle, and allow the player to take a more permanent measure in the form of a rocket launcher or a plasma grenade to destroy a vehicle. However, the weapon systems on the vehicle will still be active when this is accomplished. The ability to freeze a vehicle is most effective at disabling Banshees, allowing a player to board the vehicle without fear of being bombed. The weapon is also highly effective against Sentinels, taking only a single overcharged shot to destroy a standard Sentinel, or two charged-shots to destroy a Sentinel Major, one to deplete its shields and another to destroy it. The Plasma Pistol locks on a nearby Sentinel, making it the only weapon other than Rocket Launcher to do this. In addition to its standard offensive capabilities, there are also various elements peculiar to each game that enhances its effectiveness. In Halo: Combat Evolved, it has the ability to briefly stun opponents via its standard firing mode. Also, the overcharged shots cause heavy damage to unshielded opponents in multiplayer as well as unshielded Covenant forces except Hunters and Grunts and other forces on legendary. In Halo 2 the overcharged shot's tracking is increased from Halo: Combat Evolved, allowing for easier shield depletion's, however in Halo 3, the overcharged shot has reduced tracking from the previous installment. An overcharged plasma bolt in Halo 3 will destroy a Brute's Power Armor, making them vulnerable to weaponry fire.

In Halo 2, the colloquial term "noob combo" is usually applied to the Plasma Pistol/Battle Rifle combination due to the extreme tracking abilities of the Plasma Pistol's charged shot as well as the relative ease of achieving headshots with the Battle Rifle. The "noob combo" is controversial amongst players. In the Halo Trilogy, it is possible to use the Plasma Pistol in conjunction with melee in what is called a Plasma Punch, in Halo: CE and Halo 2 auto-update 1.1 it should only take one or two melee attacks to kill an opponent in Multiplayer. In Halo 3 the melee attack is much more effective, as a melee attack after a overcharge shot will guarantee a kill. It is also effective for a multiplayer game of Juggernaut, as one fully charged shot can deplete the Juggernaut's shield, making the Juggernaut more vulnerable to basic firepower.

The Plasma Pistol can be used to great effect from the back of a Mongoose using it paired with any weapon, but especially the Noob Combo can cause havoc on the battlefield. If used properly, this technique can help you lower the shields of many nearby enemies, and quickly, to aid your teammates in mowing them down.

It should also be noted that when compared to the plasma rifle, the plasma pistol's non-overcharged firing mode is far more accurate on medium and long ranges, although the plasma projectiles tend to arc downward a bit on long range. Furthermore, the plasma pistol can be fired much faster than the plasma rifle. This is most obvious in Halo for the PC, where it is easier to achieve high rates of fire with the left mouse button than with the right trigger of the xbox controller. When fired that fast, the plasma pistol will overheat in less than a second.

Disadvantages
The Plasma Pistol will overheat when fired non-stop for extended periods of time, or if the overcharged shot is released, which render the weapon completely useless for several seconds. Also, the weapon, while accurate at shorter ranges, has somewhat of a limited long-range accuracy due to the relatively low velocity of its shots (as compared to most other weapons). It is also a very weak weapon when shot normally, taking several shots to wear out a target's shielding and doing almost no damage to an unshielded enemy taking 17 shots to kill an unshielded player in multiplayer. The weapon's battery cannot be recharged, and thus it must be discarded when the battery is fully depleted.

In Halo 2, the overcharged shot is only capable of depleting energy shields but cannot finish off shieldless enemies, only able to defeat Sentinels in a single shot. On Easy difficulty, one shot from an overcharged Plasma Pistol will only deplete shields by 3/4. The Halo 2 Plasma Pistol's regular shots are also noticeably weak and ineffective. It is noted, though, that on higher difficulties heavy plasma pistol fire will quickly deplete your shields. In Halo 3, holding down the trigger to maintain an overcharged shot will deplete the battery gradually. Another disadvantage to this weapon is its now-reduced ability to follow the opponent. This is very rarely a weapon of choice, for most players, unless they wish to use the Noob Combo, which is a combination of the plasma pistol with another weapon that can do high physical damage to quickly kill the enemy. Although the plasma pistol cripples any vehicles rendering them unmovable for a time they can still fire any of their mounted weapons. The pistol's homing ability can be easily avoided by sidestepping.

Influences
The Plasma Pistol was inspired by the human "Zeus-class fusion pistol" from the Marathon 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 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.
 * While already wielding one, the game will only offer to "press X to pick up" if the new one has a higher battery charge. In-story, this could mean the Master Chief is familiar enough to recognize the charge level at a glance.
 * 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 like its counterpart in Halo 2.
 * 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.
 * Charged shot still does no damage.

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.” “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.”

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.
 * A charged blast from the Plasma Pistol can even drain the entire shield of an overshielded Spartan or Elite, and can strip the power armor of a Brute. A useful combo if taking out Elites is a Plasma Pistol and a rapid firing weapon or a Pistol. An overcharged shot would disable their shields then using the rapid-fire weapon it would be much easier to kill once the shields are gone
 * 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 ridiculously 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.
 * It takes 7 shots to take down an elite on normal in Halo: CE.
 * Dadab and Linglin are the only named Grunts who utilized the overcharge mechanism of the Plasma Pistol.
 * In Halo 3, it takes 7 single shots from a Plasma Pistol to detonate an active Trip Mine.
 * 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 the Halo 2 level Regret (Level), he will drop a plasma pistol.
 * It looks strikingly similar to the Constructor in both Halo 2 and Halo 3.
 * 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.
 * It is one of the three weapons found in every level in the Halo Trilogy.