Pause the game, then hold L2 and press L3, R3, L3, R3, X, Circle, L3, R3, L3, R3, Square, Triangle.
Pause the game, then hold L2 and press Square, Circle, Square, Circle, L3(2), Triangle, X, Triangle, X, R3(2).
Pause the game, then hold L2 and press Circle, Square, X, Triangle, L3, Triangle, X, Square, Circle, R3.
Pause the game, then hold L2 and press X(2), Circle(2), Square(2), Triangle(2), X, Circle, Square, Triangle.
Host an online game. Pause the game, then hold L2 and press L3(2), X, R3(2), Circle, L3(2), Square, R3(2), Triangle. Bullets from Alpha team/Rainbow will be blue lasers, while those from Bravo Team/terrorists will be red lasers.
Achieve the indicated rank to unlock the corresponding items in Multiplayer mode:
1st Lieutenant (214,000 experience points): Headgears 4 (Half-Face Mask, Reinforced Helm, Tactical Goggles)
2nd Lieutenant (172,000 experience points): Camo 3 (Pink, Blue, Woodland, Wasp, Sand, Crimson)
Captain (264,000 experience points): Merc Weapons (MG36, SPAS12, Deagle)
Colonel (535,000 experience points): Headgears 5 (Ballistic Face Mask, Riot Helm, NVGs)
Corporal (14,500 experience points): Camo 1 (Desert, Urban, Russian, Guerrilla, Fall, Desert 2)
Elite (675,000 experience points): Camo 5 (Custom 1, Custom 2, Custom 3)
First Sergeant (109,500 experience points): Headgears 3 (Bonnie Hat, Beret, Tinted Goggles)
Lt. Colonel (425,000 experience points): Camo 4 (Yellow Urban, Red Urban, Tiger, Rust, Urban 2, Grey)
Major (330,000 experience points): Military Armor (Vier Recon Armor, Diamondback Combat Armor, Anaconda Assault Armor)
Master Sergeant (82,500 experience points): Freedom Fighter weapons (AK47, Raging Bull, SV98)
Private 1st Class (3,000 experience points): Headgears 1 (Tactical Helm, Balaclava)
Sergeant (23,500 experience points): Tactical Armor (Raven Recon Armor, Vulture Combat Armor, Falcon Assault Armor)
Sergeant First Class (56,500 experience points): Camo 2 (Flecktarn, Orange, Swedish, War2k5, Alpen, White)
Sergeant Major (139,000 experience points): Black Market Armor (Typhoon Recon Armor, Cyclone Combat Armor, Hurricane Assault Armor)
Specialist (8,400 experience points): Rainbow Weapons (MP7A1, SIG552, USP40)
Staff Sergeant (38,500 experience points): Headgears 2 (3 Hole Balaclava, Baseball Cap, Breathing Mask)
In single player Co-op Story mode, some of the guns unlocked in Career mode will not be not accessible (for example, the Desert Eagle and SPAS 12); however, the terrorists in Co-op Story mode will use them. To unlock those weapons, play a mission in multiplayer Co-op mode. Pick up the terrorists' guns that are left behind after they die. Finish the level with them to unlock them at the equipment menu. You can unlock the SPAS 12, Desert Eagle, and MG36.
Another player is required for this trick. Start a game with 20 rounds for 20:00 minutes with 15 between matches. Use a rubber band to position both Analog-sticks so that you walk in circles. You will get 800 points for a game, which will gradually decrease over time.
To perform this trick, take cover against any wall. Make sure your weapon is on single shot, then fire one blind shot. Hold L2 + R2, then press and release Circle. A grenade should shoot about 20 to 30 feet around the corner. Note: This works with all grenades except for C4 and breaching charges.
Use your thermal goggles after you deploy a smoke grenade to see better.
Play the Fremont Street level and look for a ledge that has a bottle of Axe cologne. Shoot the bottle and the neon roof of the Fremont Street Experience will change to an animation of a girl in a bikini with some Axe items. This is followed by a sequence with outtakes and early animations.
When Jung must hack the computer to open the door to Irena, enemies rappel down from the windows. Before you tell him to hack, send your team to the far side of the room over near the fenced area. Then, run behind the computer and tell Jung to hack it. A trigger will activate and the enemies will start pouring into the room. Your team will take most of them out on the way to the computer. If someone on the team goes down, Jung will stop moving towards the computer and sit there (or Michael, depending on who goes down). Once there is a pause in the battle, tell him to heal your partner. You can then order them around as usual. During this time, Jung was supposed to be hacking the terminal, but killing all the enemies skips this part. Once done, tell Jung to hack it again. He will open the door to Irena. Michael will get left behind. Watch yourself; there are enemies on the stairs above you and will pick you off as you come up, especially on on the Realistic difficulty setting.
When the mission begins, make your squad rappel down the left part of the building. Then, order them to go down until they are able to breach. Next, go to the middle of the roof with the opening. Drop a C4, incendiary, smoke, or frag grenade, and keep shooting through the glass. After a few seconds, order your squad to breach into the building. Finally, rappel down into the building.
In the Dante's Casino level near the arcade, there is a machine labeled Tom Clancy's: Splinter Cell: Chaos Theory.