Apparatuses, systems, and methods in which a utility knife includes a blade guard rotatably covering the cutting edge of a blade. The blade guard can be locked and unlocked by a primary mechanism. In addition or alternative to the primary mechanism, the blade guard can be set to provide a maximum exposure of the cutting edge for cutting, a minimum exposure of the cutting edge, a maximum retraction of the blade guard over the cutting edge after performing work, or a minimum retraction of the blade guard. The tensive force required to rotate the blade guard and expose the cutting edge can also be adjusted.