Plot Armor

Plot Armor is an informal term referring to a character's unusual ability to survive, due to their importance to the story.

In the Call of Duty series, this can be seen when certain NPCs shrug off machine gun fire, grenade blasts, and other normally fatal events. Commanding officers directly in charge of the player character tend to have plot armor throughout the game, while other plot-critical characters may lose their "armor" once their role has been fulfilled. Although certain important NPCs are invincible, if they get shot enough times they will often fall down as if they died but will get up after a few seconds.

Characters without plot armor can die from any fatal event, including accidental death at the hands of the player.

If the player deliberately fires upon such NPCs, play will cease with the normal "Friendly fire is not tolerated" message. However, enemies can fire all they want, to no effect. Because of this, the player can use friendlies with plot armor to draw fire from enemies, especially at lower difficulty levels.

Call of Duty

 * At one point during "Ste. Mere-Eglise- Day", Martin's squad is pinned down by Tiger tanks. Sgt. Moody is still visible to the enemy despite taking cover, and is repeatedly shot at by the second tank's machine gun.
 * One glaring exception to the "commander rule" is Captain Price during the events aboard the Tirpitz. Once Evans leaves Price to set explosive charges, Price is scripted to die while defending the entrance.

Finest Hour

 * The player's Russian commander, Oleg Puskov, is scripted to die by sniper fire, as he discovers the German sniper they are hunting through Stalingrad has targeted Private Sokolov. Until then, he is unstoppable.
 * In the British campaign, Sgt. Starkey has plot armour.
 * In the American Campaign, Benny Church also has plot armour.

Call of Duty 2
Adherence to CO/Main Character rule.

Call of Duty 2: Big Red One
Adherence to CO/Main Character rule.

Call of Duty 3
Adherence to CO/Main Character rule.

Call of Duty 4: Modern Warfare

 * Until this entry to the series, player characters had an immunity from plot-related death. This changed when Paul Jackson, thousands of other Marines, and uncounted civilians were annihilated by a nuclear explosion.
 * Similarly, high-level NPCs such as Gaz, Vasquez and Griggs did not normally die in the manner they did in Modern Warfare.
 * Captain Price has plot armor throughout the game (except, naturally, when the player assumes the role of Price during the flashback missions).
 * Some minor characters like Massey and Baker have plot armour until their use expires (i.e. breaching a door).
 * In "Sins Of The Father", Sergeant Kamarov lacks his usual plot armour, as he can be killed during the second firefight at the guard post. This is possibly explained by the use of other character models, as the characters had disguised themselves as the Ultranationalists they had killed during the first assault on the guard post. Despite this, Kamarov is scripted to appear towards the end of "Game Over".
 * In Safehouse, the loyalist assisting the SAS has plot armour, since he is scripted to be present at Al Asad's interrogation. Al Asad in turn also has plot armour at this point since he is totally immune to damage, though Captain Price soon shoots him.
 * Macmillan has normal plot armor until his scripted injury where the player has to carry him the rest of the level. After this point he is completely immune to grenades and the like, and enemies will not attack him.

Call of Duty: World at War

 * Sgt. Reznov and Pvt. Chernov both have plot armor, until Chernov's scripted death during "Heart of the Reich".
 * Likewise, Tom Sullivan has plot armor until his scripted death.
 * Pvt. Polonsky and Sgt. Roebuck both have plot armor. During Breaking Point, depending on the player's actions, one of them loses his plot armor and dies (another scripted death), while the other keeps his plot armor.
 * When Sergeant Daletski is under MG fire in Vendetta, he just falls down and gets back up when he is shot.

Call of Duty: Modern Warfare 2

 * During the events of "No Russian", Makarov and Viktor not only have plot armor, but are also capable of shooting through any obstacle when necessary, with the exception of the bulletproof lifts. If shot, Makarov and the rest of the group will shoot and kill the player, calling him/her a traitor. This is the only time in the entire series where the player faces enemies with plot armour.
 * NPCs from the TF141 include Captain Price, Ghost (until his scripted death - Ghost is the only one of the three main TF141 NPCs that is scripted to die in the campaign), and "Soap' MacTavish. In Takedown, Royce is invincible until Meat dies, and in "Loose Ends", Ozone and Scarecrow are invincible until the DSM is connected.
 * NPCs from the Rangers include Sergeant Foley and Corporal Dunn. Pvt. Wells, in "Wolverines!", is invincible until Foley carries Raptor to Burger Town. After escorting Foley, he will stay at the Burger Town parking lot, where he will most likely die if he is not protected enough.
 * Pvt. McCord has plot armor in "Second Sun".
 * In this entry to the series, friendly NPCs are able to detect and react when the player shoots past them, and will give the usual "friendly fire" warning. Prior to this, NPCs only responded when they were actually shot by accident.
 * General Shepherd cannot be killed in "Endgame" until he is scripted to be killed by the player's knife at the climax of the level.