We review the status and applications of a defensive weapon based on high-power lasers in the battlefield. The laser weapon is a novel concept that utilizes a high-power laser beam to traverse the distance into incoming objects at the speed of light and then destroys or disables it. Various types of lasers and configurations are discussed in this review, including gas lasers, solid state lasers, fiber lasers, and the free-electron laser. We discuss various configurations, such as an airborne laser, diode pumped crystals, and disk lasers as well as heat-capacity lasers. Recent applications of ultrafast solid state lasers for nonlethal or low-collateral-damage applications are also presented.