Knife

The Knife is the standard close quarters combat (CQC) melee weapon in Call of Duty 4: Modern Warfare and one of the melee weapons in Call of Duty: World at War, Call of Duty: Modern Warfare 2 and Call of Duty: Black Ops.

Prior to Call of Duty 4: Modern Warfare, the knife was not a commonly used melee weapon in previous singleplayer Call of Duty games; it was available only in missions that feature stealth and/or reconnaissance. Before Call of Duty 4: Modern Warfare, the most common melee attack was the butt of the weapon. The knife is triggered by pressing the melee button (default V on the PC, clicking the right thumbstick on the Xbox 360, or clicking the R3 Button on the PS3), as taught in the "F.N.G." and "S.S.D.D." missions. However, on the Wii it is triggered by shaking the controller or by pressing down on the D-pad.

Singleplayer
The knife is the standard melee weapon for the player character in every installment of Call of Duty from Call of Duty 4: Modern Warfare onward. It is rarely seen used by NPCs, although they do have the ability to use a knife in Call of Duty: Modern Warfare 2. It will always be a one-hit kill on normal enemies, although it can take upwards of eighteen to nineteen knife hits to kill a Juggernaut.

Call of Duty 4: Modern Warfare
The knife will always kill an enemy in one slash or stab. In Old School multiplayer matches, however, two knife attacks are required to kill an enemy player at full health. This 2-hit-kill knifing also applies when double health is applied on Private Matches.

Call of Duty: World at War
The knife in Call of Duty: World at War is rather inconsistent in its ability to connect and kill enemies. It also makes a very loud and distinguishable swinging noise, often causing the user to be exposed, as it is highly unreliable. It is only consistent at a 1-2 foot range, where it usually guarantees a kill.

The Bayonet is an alternative to the knife, and can be attached on all (true) bolt-action rifles (Kar98k, Springfield, Mosin Nagant and Arisaka) the M1897 Trenchgun, the M1 Garand, the M1A1 Carbine and the Type 99 LMG. The Bayonet increases the lunge distance and thereby increases the odds of a successful attack.

Nazi Zombies
In the Nazi Zombies map Der Riese the players can replace their usual knife with the Bowie knife for 3000 points that multiplies damage many-fold, allowing 1-hit kills up to round 15 (give or take 2) and double or triple strikes for as long as any game could hope to last. The Bowie knife upgrade will remain after death and respawn, adding value.

Call of Duty: Modern Warfare 2
There are three knives available to the player in Modern Warfare 2:
 * The regular knife
 * The Tactical Knife, an attachment for Handguns which allows faster knife stab and faster recovery. USP .45's Akimbo attachment has the same swing speed as the Tactical Knife, but with the regular recovery speed.
 * The Throwing Knife, a ranged alternative, available as Equipment.

Also featured in Modern Warfare 2, is the perk Commando, which greatly increases the knifing lock on range, often resulting in large lunges which still kill players. Commando increases the knife's range to similar the length of the shipping crates on the Call of Duty 4 map Shipment, combined with Lightweight and Marathon this can produce a very dangerous "Witch" class (referring to the Witch from Left 4 Dead) though this tactic is considered overpowered and causes immense frustration for victims; it's use is looked down upon by non-users.

The knife cool-down time can be shortened by quickly hitting the equipment button then switch weapons button. This is most effective when used with the Throwing Knife, and is impossible with Fragmentation Grenades and the Blast Shield.

Call of Duty: Black Ops
The knife returns in Call of Duty: Black Ops. It is still a one-hit kill, but unlike the previous versions, seems to cause a very large fountain of blood to appear after knifing an enemy.

There are currently two known knives featured in Black Ops:


 * The regular knife, as seen since Call of Duty 4.
 * The Ballistic Knife, a secondary weapon that fires the blade out of the grip for a silent ranged attack.COD_Black_Ops_Knife.png
 * After having knifed someone, it seems that it will be ready to knife again faster than in previous games.

Trivia

 * All of the knifes are based on real knife models:
 * In Call of Duty 4, Call of Duty: Black Ops and Call of Duty: Black Ops (Nintendo DS) it's based off the SOG Bowie knife.
 * In World at War it's based off the KA-BAR knife.
 * In Modern Warfare 2 it's based off the Blackhawk Tatang.
 * In Modern Warfare 2, NPCs now have the ability to use the knife, although it is extremely rare. Allied NPCs will usually throw enemy NPCs onto the floor and shoot them upon close contact instead of using the knife.
 * In Call of Duty 4, the first and only time an allied NPC, or any NPC, used a knife to kill an enemy was in "Ultimatum". When Bravo Team enters the first house, Price sees an enemy and silently kills him with a knife.
 * The Call of Duty 4 knife was originally to be used in Modern Warfare 2, but the Modern Warfare 2 knife was changed to a more contemporary model. The Tactical Knife still uses the icon of the original knife.
 * There are three occasions in Modern Warfare 2 where an enemy uses a knife in an attempt to kill the player. The first two occur in "The Only Easy Day...Was Yesterday" and "Just Like Old Times"; the player breaches the door and an enemy charges at him with a knife. The player would have to kill this enemy first before killing the rest in the room. Thirdly, Shepherd stabs Soap in the chest after knocking him down during "Endgame".
 * The only time an enemy uses a knife against the player in Call of Duty 3 is during one of the quick-time events, when getting ambushed in a building by a German soldier wielding one. The German repeatedly attempts to stab the player. The fight ends when the player manages to push the knife into his own chest, where he stares at it before falling dead. this bears similarity to a scene in Saving Private Ryan, though it is the American who gets stabbed and dies in the movie.
 * In Modern Warfare 2, when Soap goes to kill General Shepherd in "Endgame", he holds the knife in his right hand and nothing in his left while the player is able to attack by hitting the fire button, this is the first time in the whole of the Call of Duty series that the player holds a knife as a primary weapon.
 * All players seem to use the Knife with their left hand, this is most likely because all of the players use their right to shoot. However, this isn't the case in Call of Duty: Black Ops on the Nintendo DS, as screenshots show the player holding the knife in their right hand.
 * It is possible to get an assist with a knife in Call of Duty 4 and Modern Warfare 2 multiplayer by knifing an enemy player who is halfway through the transition into Last Stand then having an ally finishing him off or by setting the health to double then stab and enemy player then let your ally finish him off.