Surgical stapler systems can include lockout mechanisms to restrict further movement of a jaw assembly and provide different functionality when a jaw assembly is empty and when a partially or fully fired reload cartridge is present in the jaw assembly. When the jaw assembly is empty, the empty jaw assembly lockout mechanism can arrest an open-close stroke of the jaw assembly. When an at least partially fired reload is present in the jaw assembly, a fired reload lockout mechanism can allow operation of the jaw assembly through a substantial portion of an open-close stroke, but restrict actuation of the jaw assembly in a firing stroke. The separate lockout mechanisms can be embodied in a single lockout lever actuatable by lockout actuators to three distinct positions or by two independently-operable lockout levers.