Splinter Cell: Conviction introduces a number of new gameplay features to the Splinter Cell series, one of which is the "Mark & Execute" feature, which allows the player to mark specific targets, such as enemies or objects, and shoot them in rapid succession without manually targeting each one. The player can choose to prioritize these targets, so that, for example, he can distract one guard by shooting out a light in his vicinity and then take out another guard. Another new feature is the "Last Known Position", which occurs when the player breaks the line of sight of an alerted guard. This creates a visual where the guard thinks is, allowing the player to flank his enemies.
Other new features include the ability to interrogate characters in real-time, and use objects in the surrounding environment against them. Mission objectives and key plot points are projected onto walls within the in-game world, in order to keep the player immersed in the gameplay. Several other features, such as blending into crowds, improvising gadgets, and interaction with the environment, were announced, and according to creative director Maxime Béland would have given the game "a lot of influence," but were scrapped after the development team decided that going in this direction would be taking too much of a risk.
- The events of the main game take place three years after that of
- Former Victor Coste (Howard Siegel) is being interrogated by a called "Black Arrow", and recounts the events of Conviction in the past tense.
- After quitting Third Echelon, Sam Fisher () heads to , to investigate rumors that the death of his daughter, Sarah, might not have been accidental
- As he investigates, Anna "Grim" Grímsdóttir (), Sam's former colleague, contacts him and warns him of the imminent attack by a group of hitmen.