S.T.A.L.K.E.R.: Shadow of Chernobyl
A few other groups work in the zone, and are neutral or an enemy based on certain events. Two groups are important: "Freedom" and "Duty" as they are the only two groups that the player can decide if they want to be friendly towards or not. Neither Faction will attack the player at first, and both will offer missions to the player. Freedom and Duty are at war with one another, and although th player can keep friendship with both of them at first, the player will end up having to choose a side. The player cannot join either faction, no matter how friendly the player becomes towards them, as the player's faction status in the player's P.D.A. will tell the player, the player is always a loner in this game. There are several other groups, these are almost all enemies for the player. The scientists are different though, because the player can be friends by saving one of them from a mercenary attack later in the game.