Some of the features that were present in the last four games in the series do not appear in this game. Sam's hybrid night/heat vision goggles and his multipurpose SC-20K assault rifle, which were the mainstay of the last four games, no longer appear. His light sensor is also absent, although change in the screen saturation now shows whether Sam is hidden from view. Sam can no longer move or hide dead bodies, nor can he knock enemies unconscious, as all equipment that helped doing the latter are absent. Lock picking and hacking minigames are also not included in the game. Sam has been equipped with MK.23 and MP-446 pistols with a suppressor and unlimited ammo, which helps him to takedown his enemies in a stealthy way.
One of Ubisoft's stated goals for Conviction was to make the game more accessible. According to Béland, Chaos Theory is "very hardcore", which turned off many players and disconnected people from the fantasy of being Sam Fisher. Béland contrasted the earlier games in the series with works containing James Bond or Jason Bourne, who "run fast, they don't make noise, they kill one, two, three or four guys super quickly," and he stated that Conviction delivers a similarly dynamic experience with more of an emphasis on action than previous Splinter Cell games.
Multiplayer
Multiplayer mode in Splinter Cell: Conviction involves both split screen, System link (Xbox 360), and online cooperative mode, plus a "Deniable Ops" mode, involving four modes that pit players against AI enemies in game modes such as "Hunter" (where the player must kill a set number of enemies), "Infiltration" (where the player must kill a set number of enemies without being seen), "Last Stand" (where the player must protect a bomb as enemies try to disarm it), and "Face-Off" (a competitive version of "Hunter"). "Face-Off" is the game's only competitive multiplayer mode, as it features the ability to kill the opposing player. "Hunter", "Infiltration", and "Last Stand" can be played in single-player modes and do not always have to be played with a human partner. The game does not contain the "Spies Vs Mercenaries" mode featured in the previous games of the series.
According to co-op game director Patrick Redding, the stealth in Conviction is designed around new core elements like "Mark & Execute" and "Last Known Position".
Plot
The game's story is divided into two portions. The main portion is the game's single-player campaign, which puts the player in control of Sam Fisher. The "Prologue" portion of the game, however, is accessed through the multiplayer co-op mode, which puts two players in control of agents Archer and Kestrel.
Prologue
Ten days prior to the events of the main game, Third Echelon agent "Archer" (Edward Yankie) and his Russian counterpart, Voron agent "Kestrel" (Alex Ivanovici) are deployed to Nevsky Prospekt in Saint Petersburg, Russia to halt rogue elements of the Russian military from selling advanced warheads on the black market. Intelligence from Andriy Kobin (Elias Toufexis) has pointed to drug and human trafficker Valentin Lesovsky (Mark Camacho) as the broker for the sale, and Archer and Kestrel are to terminate Lesovsky and his associate, Boris Sychev (Alain Goulem), as well as gaining Lesovsky's contact list.
Having completed their mission, Archer and Kestrel are deployed to the Russian embassy in Baku, Azerbaijan to gather intelligence on an arms deal conducted by former Russian GRU Colonel Leonid Bykhov. They observe the deal and see Bhykov betray his associate, Tagizade, ordering his men to kill him. Archer and Kestrel prevent the destruction of the weapons crates, learning that the weapons Bhykov was going to sell were Block II JDAM missile guidance kits. They interrogate Bhykov, learning that he is working with Major General Kerzakov, who is in the Yastreb Complex, an underground fortress situated underneath Moscow's Red Square.
They infiltrate the complex and learn the location of the EMP warheads. They render the JDAM kits inoperable by using their portable EMP devices, and download data from multiple servers to trace the EMP devices to the Mozdok Proving Grounds. Sneaking aboard a supply truck, they infiltrate the Proving Grounds and secure the EMP devices with the help of Kobin. During their extraction, Third Echelon director Tom Reed (James A. Woods) calls Archer and orders him to kill Kestrel; concurrently, Kestrel reads Archer's OPSAT (Operational Satellite Uplink) device, forcing him to act in self-defense. Whilst either player can die, the canon ending has Kestrel fatally shooting Archer; overcome with grief and unaware that Kobin has entered, Kestrel is shot in the head.