Combat knife

The Combat Knife, occasionally referred to as the Close Quarters Combat Weapon System, is a multi-purpose knife used by the United Nations Space Command.

Design details
The UNSC's multi-purpose combat knife has a blade 20 cm long made of high carbon steel, an anti-flash non-reflective titanium carbide coating, edge coated for corrosion and rust resistance and is 43.3 cm when sheathed. All UNSC troops are issued a combat knife for field and utility uses, as well as a backup weapon for desperate close combat situations. The weapon is also weighted for throwing.

History
Knives have been used in battle almost since the dawn of warfare, first as a sharp piece of rock, and then, when metal proved effective, during a period of time where projectile weapons were not readily available. Even after the invention of the firearm, knives were still used as bayonets for close-quarters combat, and in the event of an enemy's cavalry charge. As more modern weapons came about during the 20th-21st centuries, combat knives became almost exclusively used for utility purposes in the field, and were only employed as a weapon during desperate situations, simply due to the fact that they were impractical for use during combat in most situations due to the presence of firearms and other advanced weaponry.

By 2552, the UNSC still uses knives in their operations, showing that such an easily created and accessible weapon and tool still has a place on the battlefield thousands of years after its creation.

Development
A larger version of the combat knife, called the machete, was intended to be used in pre-release versions of the Halo: Combat Evolved build, but was cut before it made it into the final game, replaced with the game's use of melee attacks from any weapon.

The combat knives make their first gameplay appearance as ornamental add-ons on the lower backs of Orbital Drop Shock Troopers in Halo 2. The combat knives also appeared in Halo 3 live-action commercial trailer Halo: Landfall, attached on the ODST's left shoulder. The weapon returns to Halo 3 as an ornamental add-on for the MJOLNIR CQB permutation, as a sheathed combat knife attached to the left chest section.

The combat knife is first used in hand-to-hand combat in Halo Wars, when Sergeant John Forge uses his combat knife, which he has nicknamed "Lucy", to wound Ripa 'Moramee before killing the Sangheili leader with his own Energy Sword. Another scene where the combat knife is used was in Halo 3: ODST, where Gunnery Sergeant Edward Buck uses one to kill a Jiralhanae Chieftain by stabbing him in the neck, afterwards casually flicking the alien's blood off its blade. In the Halo Legends episode The Package, Frederic-104 uses two combat knives to fend off and kill the two Sangheili that were pursuing Kelly-087 and John-117 inside the Covenant flagship. These knives are stored in the pauldrons of Frederic's Mark IV MJOLNIR armor. Also in the Halo Legends episode "The Babysitter," Cal-141 uses a combat knife to assassinate several Unggoy.

In the Halo: Reach world premiere cinematic, Emile-A239 is seen sharpening a kukri against his shoulder plate. In-game, the combat knives are used to perform extended melee kill sequences called assassinations by holding down the melee button when behind an opponent.

By default, all players have their knife holstered on the upper-left of their chest. However, a few chestplates can alter the position of the knife, such as the "Collar/Patrol" and "Assault/Sapper" which are attached below the left arm, and "HP/Parafoil" which is attached horizontally on the breastplate. The right Security shoulder variant has a Kukri attached to it similar to the one worn by Emile. The Security shoulder allows for a possibility of having two combat knives on you at a time.

Trivia

 * Frederic-104 possesses particular skill with combat knives, and is rather fond of their use.
 * This is the signature weapon of assassinations.
 * When performing an assassination, a second knife spawns out of nowhere. This can be seen clearly in Theater; despite using a knife to assassinate your opponent, it still appears sheathed on your chest.
 * In Halo Wars, John Forge uses his combat knife, "Lucy," to distract the Arbiter before finishing him off with his own Energy Sword
 * During cut scenes in the Halo: Reach campaign, the knife will sometimes not show up on the player for some reason.
 * In Red vs Blue Revelation Episodes 19 and 20, Tex and Washington (respectively) use their knives against the Meta.
 * Emile-A239 is the only known character to use a Kukri for a knife. Whether he acquired it by his own means, or he was for some reason issued one is unknown.
 * In The Babysitter, Cal-141 used a combat knife to kill a Grunt by stabbing its head.
 * The Combat Knife reappears in Halo 4, via assassinations.
 * There is a small, faint, UNSC symbol on the blade.
 * In Halo: Combat Evolved Anniversary, the armored marines carry a combat knife near their left shoulders.
 * The Halo 4 combat knife resembles the MTECH USA XTREME MX-8054 Tactical Fixed Blade Knife.

Internal

 * Energy Dagger
 * Curveblade
 * Energy Cutlass
 * Jiralhanae Combat Knife

External

 * Bayonet on Wikipedia
 * Combat knife on Wikipedia

Cuchillo de Combate