Perfectionist is the hardest difficulty setting introduced in Tom Clancy's Splinter Cell: Blacklist. The difficulty removes the ability for players to 'Execute', makes Sonar Goggles unable to see targets through walls, decreases the detection time for hostiles to the player and increases the damage that hostiles inflict on the player. The mode also increases the scarcity of ammunition for the player's weapon by eliminating Weapon Stashes for the player to access through the missions.
Perfectionist mode was initially introduced for fans of the previous games of the series before Splinter Cell: Conviction, as it removes added in features, such as the main mechanics of Mark and Execute. The difficulty mode also removes other 'newer' features to the Splinter Cell series such as the ability for Sonar Goggles to see through walls (acting more like basic thermal vision from the previous games) and increasing the amount of time that enemies detect the player. The damage output from enemies is greatly increased as well, with enemies only needing a few shots to kill the player (even when wearing heavier armor). The difficulty setting is available in both the campaign mode and cooperative mode of Splinter Cell: Blacklist.