Surgical end effectors are disclosed. The surgical end effectors can include a first jaw, a second jaw rotatably coupled to the first jaw, and a lockout arrangement configured to prevent rotational movement of the second jaw toward the first jaw unless an unfired staple cartridge is positioned in the first jaw. The lockout arrangement can comprise a pivotable lock configured to pivot between a locked orientation and an unlocked orientation, a shiftable lock bar, and/or a spring-loaded lockout lever.