In video games, the cover system is the digital adaptation of the real-life military tactic of taking cover behind obstacles, for purposes of attaining protection from enemy ranged or area effect attacks, such as gunfire or explosions. With the passage of time, cover systems specialised into lock-on cover systems where players had to hit a key to get behind & exit from cover, and passive cover systems where players would automatically enter and exit cover. Both flavours of this system had equal amounts of fans and haters. Regardless of the system players choose, a poorly implemented cover system causes players to be dragged out of the momentum of a fast paced action sequence. Countless players have complained when the protagonist would not exit cover even after repeated key presses while countless others have complained that their character accidentally enters cover when they least expect or want it to.
Examples
Army of Two: The Devil's Cartel
In Army of Two: The Devil’s Cartel, moving between covers is unnecessarily tricky with players unable to select the cover they desired and sometimes being unable to get into cover.