Infection

Infected is a custom game mode in Call of Duty: Modern Warfare 3 exclusive to private match.

Gameplay
The game starts with one player on the infected team. The surviving players must hide or survive from the infected. The survivors are the players who are not infected, hence the name "survivors". The survivors spawn with an unknown weapon (pending on what the custom settings are) and must survive by killing the infected before they kill you. 100 points are given to all players who are not infected every time a survivor is infected. The name given with the points is "Survivor". The round ends when the last survivor is killed/infected and the new round will start pending on a new player to be infected.

Trivia

 * In most custom matches, the infected are normally given a USP.45 with tactical knife and no bullets. However the infected can spawn with Riot Shields depending on the match settings.
 * In many maps, there are in which it is very hard for Infected to reach the survivor such as the lamppost on Underground or the magazine stand in the northeast area of Resistance.
 * Infected players do not have specific models and will appear as human soldiers.
 * The 100 point bonus when surviving a death of a survivor team-mate is not added to your actual XP count but will be added to the score of the private match.
 * The same concept is applied to your K/D in these matches. It will not affect your overall K/D ratio, regardless of how many people you killed or how many times you died throughout the whole match.
 * If the player gets Juggernaut on, infected players will show a unique Juggernaut armor, with a black finish, instead of the whitish armor.
 * It is very similer to the infamous tag game "Zombie tag"

Video
Video:First Game of Infection (MW3) Gameplay of Infection