One embodiment of a trigger system with an integral selector for semi-automatic firearms. A selector allows the user to choose between two modes and rates of fire. A trigger (1) is made to allow passage of the lower portion of a selector cam (5) to the exterior of the firearm. A selector lever (6) is affixed to the lower end of the selector cam (5) on the exterior of the firearms action. Turning the selector lever (6) rotates the selector cam (5) which tilts a pivotal disconnector (3) on its axis, varying the amount of disconnector (3) engagement with a hammer (2). The variance in the disconnector (3) engagement causes the firearm to fire in one of two modes, firing one round with a trigger pull and resetting with trigger release, or firing one round with trigger pull, and firing another round with trigger release. Other embodiments are described.