Pros: Online gameplay featuring coop and verses mode
Cons: Short Only 10 missions
The bottom line: Splinter Cell changed the way people look at the FPS. Forget Halo and GTA; this game will grab you and keep a hold of you with a high replay value!
The graphics in Chaos Theory feature a number of improvements, including the addition of normal mapping and HDR lighting. The game also features a number of major changes and improvements to the series' basic gameplay.

Chaos Theory features refined stealth mechanics. In addition to the standard light bar, the game also features an aural monitor that measures the noise that Sam makes, along with the ambient noise of the environment. It is important for Sam to make less noise than his surroundings, otherwise, the enemy guards will hear him.

The AI detection has been altered as well. In former titles, after Sam would leave a certain area, the game would automatically do a sweep of the previous area for all unconscious or dead bodies in a well-lit spot. If any were found, an alarm would be triggered. In Chaos Theory, the bodies have to be discovered by a patrolling guard in order to trigger an alarm.

Being spotted by enemies will still trigger alarms, and alarms will still cause enemies to become more alert and combat-ready (such as causing them to don flak jackets and helmets). However, triggering too many alarms will no longer cause the game to end automatically. Even killing civilians or friendly soldiers won't cause Fisher to fail the mission, although doing so will cause Fisher to be seriously chastised by his superior, and cost him significantly in his mission score.

Chaos Theory is also the first game in the series to keep track of mission performance. Missions are summarized upon completion with various statistics such as the number of times detected or the number of guards killed.

Chaos Theory adds a combat knife to Sam's close-quarters combat abilities. Sam can use the knife in multiple ways, such as threatening an enemy during an interrogation, or killing an enemy in close-quarters combat. Sam can also attack enemies in combat from any direction, not just from behind. He also has the option of using lethal or non-lethal force when ending an interrogation.