Grand Theft Auto IV introduces a new system of cover(not so different from the one used in the Gears of War series. By pressing a button,Niko Bellic will hide behind the nearest cover,with a great number of animations for each type of cover(i.e. crouching behind a car,rolling to reach a cover faster,or even sliding on his knees). Behind a cover,Niko can lock-on enemies(or manually aiming to them) and exposing himself when the fire button is pressed,and retreating back when he ceases fire.He can also blind firing when in cover,but the aim is less accurate and he cannot lock-on enemies. In Multiplayer using cover can save your life in many occasions.