As with previous entries in the franchise, Chaos Theory follows the activities of Sam Fisher, an agent working for a covert-ops branch within the NSA called "Third Echelon".

The game has a significantly darker tone than its predecessors, featuring more combat and the option for Fisher to kill people he interrogates instead of merely knocking them out.

As a result, it was the first Splinter Cell game to receive an M-rating by the ESRB, an assessment which has since been applied to all subsequent releases in the series.

Chaos Theory's Xbox and PC versions of the game received critical acclaim;[13][14] the GameCube and PlayStation 2 iterations were also released to generally positive reviews.

A remastered HD edition was bundled with the first two games of the series as part of the Splinter Cell Trilogy for the PlayStation 3, released on December 20, 2010.

They will move furniture to create cover, detect changes in the environment (such as whether or not scanners have been hacked, lights have been shot or turned off, doors left open, and materials have been cut), will use team-based tactics to provide covering fire and flank Sam, and even light flares in dark environments to possibly reveal where the player may be hiding, and even detect Sam through seeing his reflection in a mirror.

As an expansion on Sam's ability to shoot while hanging upside down (introduced in Pandora Tomorrow), he can now choke down or break the neck of enemies below him.

However, the ability to shoot around corners has been removed, but this is balanced by being able to switch the side of Sam's body the gun is on while in a firing position.

If the device cannot be disabled, it will temporarily malfunction, such as causing the blue screen of death when attacking computer towers.

He can switch back to any Sticky Camera that has not been destroyed by using the CS gas attack or due to enemy fire.

The Wallmine also returns from previous installments; a wall-mounted explosive equipped with a motion sensor that detonates when enemies move in front of it.

Considering this to be a violation of Article 9 of the post-World War II Constitution and blaming the I-SDF for information warfare attacks against their countries, Chinese and North Korean forces establish a blockade in the Yellow Sea against Japanese shipping.

As Japan is an ally of the United States and, by extension, the NSA's Third Echelon, the US Navy dispatches an advanced warship, the USS Clarence E. Walsh (CG-80), to the Yellow Sea, with hopes that China and North Korea will back down.

Sam Fisher is dispatched to a lighthouse on the Talara, Peru coastline, to locate Bruce Morgenholt, an American computer programmer who has been captured by a Peruvian separatist group led by Salvadoran revolutionary Hugo Lacerda.

Following a lead discovered in Panama, Fisher travels to New York to investigate Abrahim Zherkezhi, a man who worked with Morgenholt.

He finds that Displace International, a US-based private military corporation owned by his old friend Douglas Shetland, is protecting Zherkezhi.

Fisher breaks into the Displace offices and learns of Milan Nedich, a Bosnian Serb arms supplier and war criminal, who has relocated Zherkezhi to Hokkaido.

Fisher heads to Seoul and learns that Displace International orchestrated the war, having used the Kernels gained from Zherkezhi to hijack North Korea's missile systems and sink the Clarence E. Walsh to draw the United States into a war from which Shetland could "tear it all down, and start over", declaring that the politicians and bureaucrats let the country dying.

Third Echelon sends Fisher to a bathhouse in Tokyo to spy on a meeting between Shetland and his accomplices, who turn out to be the I-SDF.

Following Shetland's death, and having acquired a copy of the Kernels from him, Otomo attempts to return Japan to Imperial rule; he blackmails Japanese government officials and senior JSDF officers by threatening to use the algorithms to launch a North Korean nuclear missile against a Japanese city.

Otomo stands trial at the United Nations and takes full responsibility for the entire Korean crisis, returning stability to the region.

Ubisoft was so pleased with Tobin's work that they decided to release the album several months ahead of the actual game.

For the recording of Chaos Theory – Splinter Cell 3 Soundtrack, Tobin hired a live band whose members ranged from Mexican composer Nacho Méndez [es] to Japanese flutist Eiji Miyake.

"[99] Rob Semsey of TeamXbox gave the game 9.8 out of 10 and said, "The formula has been tweaked to an almost perfect mix of story and engrossing gameplay that still requires more use of brain over brawn...

Maxim gave the game a perfect ten and stated: "No longer is there just one way to solve a treacherous night mission before the enemy picks up your audio signature: stealth will pay off just as well as good old-fashioned ultraviolence.

"[105] The Sydney Morning Herald gave the Xbox, PC and PS2 versions all five stars and called it "Visually spectacular and hugely rewarding.

"[94] However, the same newspaper also gave the DS version half of that score (two-and-a-half stars) and said that the frustration "is compounded by the choppy, stuttering frame rate of the 3D visuals, making the already convoluted controls feel twice as sluggish.

"[95] The New York Times gave the game a favourable review and stated that "Perhaps Sam is just getting older, perfecting his skills while losing some feistiness.

"[106] Jim Schaefer of Detroit Free Press gave the Xbox version three stars out of four, stating, "I'll reserve a four-star rating for the next time this series takes big leaps.

"[93] Splinter Cell: Chaos Theory was a commercial success, selling 2.5 million units by the end of March 2005.