Third-person shooters
Cover system in Winback
While Metal Gear Solid was one of the first third-persongames to allow you to press up against walls, it was WinBack: Covert Operations, released in 1999, which was the first third-person game to allow you to pop out of and shoot around a piece of cover. This mechanic was refined in Hideo Kojima's Metal Gear Solid 2: Sons of Liberty, where Snake or Raiden are able to take cover behind walls, boxes or crates and pop out to shoot at enemies, while the improved enemy AI allowed enemies to also take cover from the player character; the enemies would often take cover to call for backup, and during battle, they would take cover then pop out and shoot at the player or blindly throw grenades from behind their cover.
This mechanic was developed further in Killswitch which allowed the player to transition between pieces of cover, throw grenades, and blindfire. Gears of War later refined this cover system and was very well received by the gaming press, to the point that nearly every third-person shooter released after Gears of War has incorporated a cover system. An additional mechanic it added to the cover system was roadie running. Cliff Bleszinski, Gears of War's Lead Designer, has said that the act of moving between pieces of cover was very much inspired by swinging between platforms in Bionic Commando.
Vanquish attempted to reinvent the cover system, by having bullets and missiles coming from all directions in a manner reminiscent of bullet hell shooters and with cover being easily destroyed, forcing the player character to be on the move, while the game also penalizes the player on the scoreboard for the amount of time spent in cover. Its slide-boost mechanic also allows the player to slide-boost into and out of cover at high speeds, acting as both a defensive escape and an offensive setup, increasing the pace and opening up new gameplay possibilities for cover-based shooters.