Left 4 Dead is a Valve survival action game, which combines the experience of multiplayer's social entertainment, such as Counter-Strike and Team Fortress, with dramatic experience, narrative made popular in the classic single-player action, how It would be the Half-Life series games. Situated immediately after the long-awaited zombie apocalypse, L4D's single-player game modes and co-op games are played in four films that stretch in a variety of urban and rural environments. Each "movie" has a team lens, consists of five large maps and can be played by 1 to 4 human players. The new technology called the "AI directory" is used to generate a different experience each time the game is played. As in Hollywood movies, the director appeals to new monsters, sounds and actions, adapting the game experience according to team performance. In Left 4 Dead's lyrics. The modes of players can play as a survivor or as one of the four types of "BOSS infected". Each of the "Infected Heads" possesses an exceptional mutant capacity - such as a 50-foot language Lasso (smoking) or a huge stomach full of explosive methane gas (Boomer) - instead of traditional firearms.