Fisher officialy retired from Third Echolon gets contacted by an old partner and lead onto a hunt after the killers of his daughter. While this seems like a simple mission it begins to grow into something bigger while the story unfolds.
Conviction has some new features like the Mark and Execute mode which allos Fisher to mark a number of enemies as targets and execute them instantly by simply pressing a single button. This makes the game why more accessible for new players who have a hard time aiming during action scenes otherwise, reducing the game to a pure stealth game.
While this feature reduces the difficulty a lot it prevents the game from becoming a simple shooter.
New is also the option to interrogate hostages by "using" them on other objects, allowing for special cutscenes like smashing a toilet with their heads or pressing their face on a hot plate.
The main campaign can only be played alone but the game also features a coop campaign that tells the prolog of the story.