Counter-Strike 1.6

Counter-Strike 1.6 is a MOD for Half-Life that is set in a teamplay mode

Play the world's number 1 online action game. Engage in an incredibly realistic brand of terrorist warfare in this wildly popular team-based game. Ally with teammates to complete strategic missions.

Take out enemy sites. Rescue hostages. Your role affects your team's success. Your team's success affects your role.

There is only one outcome in each scenario and you will have to prove your allegiance every time you pull the trigger.