Only found in multiplayer, it is available if the player removes a primary and/or secondary weapon, which is then replaced by Combat Knife in-game. In addition, planting an Assault Shield will leave the player with their other weapon (if they had one) and a Combat Knife. Therefore, a Combat Knife does not cost an Allocation Point in Create-a-Class.
Compared to the standard knife, it features a faster melee speed and a small amount of lunge. It is held in the right hand, as opposed to the standard being held in the left. The player also does not grunt when knifing, unlike with the standard. Lastly, equipping the Combat Knife grants a 50% increase in sprint duration. Another unique feature is that while the Combat Knife is equipped, pressing the fire button will use the knife. It should also be noted that the combat knife cannot be used to destroy ground scorestreaks such as the Sentry Gun and Guardian.
The combat knife can be customized by applying camouflages on the default knife.
The challenges for the camouflages are:
DEVGRU - Get 10 kills with the Combat Knife (knife is held instead of a weapon).
A-TACS AU - Get 20 kills with the Combat Knife (knife is held instead of a weapon).
ERDL - Get 40 kills with the Combat Knife (knife is held instead of a weapon).
Siberia - Get 60 kills with Combat Knife (knife is held instead of a weapon).
Choco - Get 80 kills with the Combat Knife (knife is held instead of a weapon).
Blue Tiger - Get 100 kills with the Combat Knife (knife is held instead of a weapon).
Bloodshot - Get 120 kills with the Combat Knife (knife is held instead of a weapon).
Ghostex: Delta 6 - Get 160 kills with the Combat Knife (knife is held instead of a weapon).
Kryptek: Typhon - Get 200 kills with the Combat Knife (knife is held instead of a weapon).
"Standard issue military knife for CQC. Fast, quiet and deadly."
The Combat Knife reappears in Call of Duty: Ghosts. Equipping the Combat Knife grants a 75% increase in sprint duration. Just like in Black Ops II, the fire button will use the knife. Unlike in Black Ops II, the Combat Knife can be selected like other weapons in the Create-A-Class directly. In addition, it is automatically selected when the player clears their Primary Weapon in Create-A-Soldier. It can be picked up and dropped during gameplay, unlike in Black Ops II and Advanced Warfare. The Combat Knife is also found as the last weapon in Gun Game, where it is used with the Throwing Knife. Getting kills with the Combat Knife in Gun Game does not count towards their streak, and instead will simply act the same as a regular melee kill in Gun Game would. Equipping the Combat Knife in Multiplayer gives players an extra perk slot. The Combat Knife is the primary weapon of the Maniac gunstreak, alongside the Throwing Knife.
"Gold plated Combat Knife with Fast Melee. Unlocked at Prestige 5."
A patch on June 3rd, 2014 (June 4th, 2014 for some consoles) released a Gold Combat Knife. Players Prestige 5 will be able to access it immediately. It functions similarly like the Combat Knife from Call of Duty: Black Ops II, as it does not need to do the lengthier grab-stabbing animation. It is automatically unlocked in Private Match and Local Match along with the Gold PDW.
The Combat Knife returns as a weapon that can be used in the primary or secondary slot in Call of Duty: Advanced Warfare. There is no lunge on this iteration of the Combat Knife, making it considerably harder to use compared to its past incarnations. The knife drips blood after a kill (or paint instead if the player has Paintball Effects on).
To equip the Combat Knife in multiplayer, the player should simply remove their primary or secondary weapon depending on where they want it. In addition to it being able to be used that way, if the player crouches or goes prone in the Swimming Pool on the map Retreat or Terrace, they will not be able to use a gun, and a Combat Knife will be equipped instead.
The Combat Knife appears in Exo Survival, but only on the maps Retreat and Terrace by crouching or going prone in the pool like in multiplayer. Since most enemies will avoid going into the pool and can shoot at the player from outside of it, the Combat Knife has no real use, and it is unlikely the player will be able to get a kill with it.
The Combat Knife returns in Call of Duty: Black Ops III. It is a secondary weapon, under the Melee category. Unlike in some previous games, the Combat Knife has to be selected in Create-a-Class rather than it being the default weapon for weapon slots without an equipped weapon. Like ordinary weapons, it also costs one Unlock Token to unlock and it takes one Pick 10 point to equip. It cannot be equipped with any attachments, though it has camouflage unlocks and can be prestiged after reaching max weapon level (11), thus can be customized with a Clan Tag or Kill Counter display which appears at the end of the handle.
Unlike Fists, which are the player's default "weapon" for unequipped slots, as well as the Weapon Butt, the Combat Knife kills in one hit even when facing the enemy. Even when equipped, meleeing while holding another weapon will result in using that weapon's stock to smash the enemy, so switching to the Combat Knife is recommended when in a close-quarters scenario, especially when the primary weapon is ill-suited for such combat (such as a sniper rifle). When attacking an enemy, there is often a short animation where the character stabs the enemy player, making the Combat Knife somewhat slow to engage multiple players at once. Pressing the 'reload' button while having the Combat Knife equipped will trigger a special animation of the character flipping the knife around their hand.
In update 1.04, new weapons were introduced that can be unlocked via Supply Drops which act as near-cosmetic counter-parts to the Combat Knife: the Butterfly Knife, Wrench and Brass Knuckles. Other melee weapons since then have been added as well.
The Combat Knife is available as a secondary Melee weapon and is unlocked at level 37. Like in Call of Duty: Black Ops III, the Combat Knife has to be selected in Create-a-Class rather than it being the default weapon for weapon slots without an equipped weapon. Like ordinary weapons, it takes one Pick 10 point to equip. It cannot be equipped with any attachments, though it has camouflage unlocks.
It is often overlooked in favor of other secondaries, such as pistols. This is because when a primary weapon runs dry, a pistol is much more effective than a knife in order to survive long enough to acquire a new weapon. As this weapon is only usable out to a considerably short range, sprinting or sliding or any form of advanced movement is used to close the gap between an enemy, often allowing them to kill one quicker. As well, due to the lunge animation, players will be left vulnerable in many scenarios. Even with these downsides, the Combat Knife has many positive features. It will never run out of ammo, though the delay with lunging could be considered a reload or reset of sorts. It is completely silent, requiring no use of the suppressor, so despite being ineffective in direct confrontations with multiple foes, this weapon is surprisingly effective in flanking, where enemies can be silently eliminated, one by one. It is also an instant kill, meaning that time-to-kill doesn't really apply to this weapon, except when lunging. Speaking of which, one only needs to be sprinting to lunge at an enemy - when in range, the lunge animation will automatically kick in, guiding you to a kill. Also, the only way an instant kill from a melee can consistently occur is with the Combat Knife Finally, it is significantly more effective when in small rooms. An example would be if one were using a Sniper and an enemy attempts to remove them from their perch from behind, the Sniper could pull out their knife and wait behind a corner to immediately kill their foe.
Although Diamond Camouflage is obtained by completing all camouflage unlocks for Specials, the "Weapons Mastery" challenge claims that the player needs to complete Mastery for every primary and secondary weapon.
The Black Ops II logo is visible on the Combat Knife.
The Combat Knife is considered a Special weapon and thus is needed for Diamond Camouflage for Specials.
If the player is the top player in the Winner's Circle and their showcase weapon is the Combat Knife, the soldier will perform some tricks with the Combat Knife.
The player's place affects what their character will do with the knife, if the player is 3rd Place, they will simply hold the knife, if the player is 2nd Place, they will slide their palm against the knife and touch the tip, and if the player is 1st Place they will toss the knife and catch it.
The player can "zoom in" while using the Combat Knife if they hold the aim button in.
In CodCast, if a player has a Combat Knife equipped, the icon will be that of the Ballistic Knife.