|The canonicity of this subject in the Metal Gear series is ambiguous.|
Emotive Ammo, also referred to as Emotion bullets are a type of ammunition utilized in Metal Gear Solid 4: Guns of the Patriots. As the name implies, its function is to, after making contact with a soldier, cause him or her to undergo varying emotions caused from being on the battlefield. The emotions are crying, screaming, laughter, and rage, and which emotion the soldier will be afflicted with after it hits him/her depends on the color. Laughter is yellow, screaming is green, crying is blue, and rage is orange. Regardless of what emotion they were afflicted with from the Emotive Ammo, the afflicted soldiers will fall unconscious soon thereafter and foam at the mouth.
Laughter Emotive Ammo
The Laughter Emotive Ammo, when fired upon a target, will cause them to undergo an uncontrollable fit of laughter. This consequently also gives the affected soldier a sadistic sense of humor, often firing his or her weapon at both his/her friends and his/her enemies just to get a good laugh out. Since this isn't Snake directly killing an enemy it won't count towards kills if a player is trying to get Stealth Camouflage and/or the Big Boss Face Camo. They'll also fire intermittently and inaccurately at Snake if he is spotted.
Screaming Emotive Ammo
The Screaming Emotive Ammo, when fired upon a target, will cause them to undergo a screaming fit, drop their weapons, and sometimes even flee the battlefield in fear.
Crying Emotive Ammo
The Crying Emotive Ammo, when fired upon a target, will cause them to undergo a crying fit, dropping onto their knees as well as dropping their weapons, and cry uncontrollably.
Rage Emotive Ammo
The Rage Emotive Ammo, when fired upon a target, will cause them to undergo an uncontrollable sense of rage and anger, often breaking cover and rushing at the enemy, either killing several enemies or are themselves killed by them. They'll also attack Snake if he is in their line of sight, and if no one is present, will struggle to contain the emotion.
Emotive Ammo is unlocked and able to be purchased from Drebin if the player decides to go through a second playthrough. It usually affects PMC soldiers the most, although it can also affect the soldiers from the Middle Eastern militia, South American rebels, and the Paradise Lost Army as well. Like most ammunition, especially tranquilizer rounds, they take an immediate effect if it was delivered via headshot. It also affects the Beauty and the Beast members: If an emotive ammo of a certain color is fired on a Beauty and the Beast member with the corresponding emotion they have, it will drain their psyche. However, it is to a smaller extent than normal tranquilizer darts.