Successfully complete the game on Perfect Agent mode to unlock Dark Agent mode.
Defeating the final Boss in Mission 13
When the final Boss jumps to the platform you are standing on, he will lunge at you with his sword. Right before he swings it, dive out of the way. If done correctly, he will trip and fall. Quickly grab his sword from the ground next to him before he gets up and start attacking him with it. Note: The sword can be used to hit three consecutive times by quickly pressing RT(3). If he manages to get away, he will summon his sword back to him. After this happens, just wait for him to jump back onto your platform and repeat the process.
Dodging the final Boss' moves in Mission 13
When the final Boss shoots plasma balls at you, just move out of the way. When he teleports onto your platform and starts running at you with the sword, just dive roll out of the way immediately before he swings the sword. This will save you from taking a lot of damage.
Easter Egg: Arena Showdown
Whenever you die, it will say to press Back for debriefing. If you don't press it for a while, it will go into debriefing for you. In Arena | Showdown though, it won't. You can watch your dead body lay there for as long as you want. Zhang Li will still be jumping around on the camera in the top right. Waiting there for 5 minutes will make Zhang Li do a victory dance. He will perform a dance move every time he lands and will jump up onto another platform every now and then. If you look closely, he does the exact same moves some people do in the dance club on Nightclub | Stakeout.
Easy weapons
When one player has gotten a weapon that another desires, go to Club: Stakeout on Agent mode. Drop that player's weapon to a second player. Have any one of those players continue through the level normally. If done correctly, the new player can have the weapons in less than three minutes. The faster way through the level is to run in the club after the first objective is complete unarmed, and rush to the very top to Jack Dark.
Gamer Points
Accomplish one of the following tasks to get 20 Gamer Points:
Complete a Co-Op mission on the Dark Agent difficulty setting.
Complete a Solo mission on the Dark Agent difficulty setting.
Get 10 kills using explosives in any Multiplayer mode.
Capture 10 flags in Capture The Flag mode.
Get 10 headshot kills in any Multiplayer mode.
Get 10 kills in Killcount mode.
Get 10 kills in Team Killcount mode.
Get 10 Melee kills in any Multiplayer mode.
Survive 10 minutes in Onlsaught mode.
Infect 10 players in Infection mode.
Survive 10 rounds of Eradication mode.
Get 10 sniper kills in any Multiplayer mode.
Score 10 points in Territory Gain mode.
Destroy 10K CR of property in Sabotage mode.
Get 100 kills using explosives in any Multiplayer mode.
Capture 100 flags in Capture The Flag mode.
Get 100 headshot kills in any Multiplayer mode.
Get 100 kills in Killcount mode.
Get 100 kills in Team Killcount mode.
Get 100 melee kills in any Multiplayer mode.
Survive for 100 minutes in Onslaught mode.
Infect 100 players in Infection mode.
Survive 100 rounds of Eradication mode.
Get 100 sniper kills in any Multiplayer mode.
Score 100 points in Territorial Gains mode.
Destroy 100K CR of property in Sabotage mode.
Get 1,000 explosive kills in any Multiplayer mode.
Get 1,000 headshot kills in any Multiplayer mode.
Get 1,000 kills in Killcount mode.
Get 1,000 kills in Team Killcount mode.
Get 1,000 melee kills in any Multiplayer mode.
Infect 1,000 players in Infection mode.
Survive 1,000 rounds of Eradication mode.
Get 1,000 sniper kills in any Multiplayer mode.
Complete five Co-Op missions on the Dark Agent difficulty setting.
Complete five Solo missions on the Dark Agent difficulty setting.
Complete Co-Op on the Agent difficulty setting.
Complete Co-Op on Secret Agent difficulty setting.
Complete Single Player on Agent difficulty setting.
Complete Single Player on the Dark Agent difficulty setting.
Complete Single Player on Perfect Agent difficulty setting.
Complete Single Player on Secret Agent difficulty setting.
Complete Co-Op on the Dark Agent difficulty setting.
Complete Co-Op on Perfect Agent difficulty setting.
Play 10 Dark-Ops games.
Play 10 Deathmatch games.
Play 100 Dark-Ops games.
Play 100 Deathmatch games.
Play 1,000 Dark-Ops games.
Play 1,000 Deathmatch games.
Rare game references
When you are creating a deathmatch game with bots, look at the names of some of the bots. There are references to other Rare games. For example, "BOT-GRUNTILDA" is the witch from Banjo-Kazooie.
Secret passage in Mission 7
Before Mission 7, select the demolition kit from the weapons menu. During the mission, after you kill the two brothers go across the bridge towards the rocket. When you get to the rocket, go left and down that road. When you get to the end of the road, there should be two doors (one on the left and another on the right). If you try to open them, they will say "secured". If you go on to a ramp that is on the right side of the left door, there will be a crack in the wall. Use the demolition kit to blow up the crack to get into the door.
See more in Cover mode
While in Cover mode and standing, move the crosshairs up to the very top then over towards you. You will be able to see more of what is on the other side of the cover that you could not see before.
See through wall in Desert
In the Desert Multiplayer map, there is an area where you can take cover and see through the wall. In order to do this, you must have Bases 2 and 4 open. Go into the cave temple base, then go through the hall, and up the sand hill, not the stairs. Go in the little courtyard from either entrance then turn left. There should be a bowl near the wall. Stand as close to the wall and as far in as you can into the wedge created. While standing, go into cover. If done correctly, you should be able to see through the wall. This is most effective during the Infection game type with the Plasma Rifle. Hide there and whenever you see a skeleton, use the secondary function (invisibility). They will usually walk out because it is very difficult to see you.
Weapon locations
The following is a list by level of all the weapons and where to find them. Note: The first and last level do not count for getting weapons. To get a weapon to keep for later use, keep it in your inventory at the end of the level. This is also useful with the "Easy Weapons" trick. These weapons were all acquired on Agent mode.
Datacore: Demolition
P9P (Pistol): You start with this gun.
Nightclub: Stakeout
DEF-12 Shotgun (Close Combat): Find on the enforcer in the beginning (after you scan him).
Falcon (Pistol): Found on almost any guards, such as the first two.
Frag Grenade (Thrown): Hidden behind a vent in the basement. The stairs leading down are located in the back right corner of the nightclub from the front door. After you have gone down the stairs there should be two vent coverings. Break them and get the grenade.
UGL Liberator (SMG): Found on the guard on the third floor. He should have two of them.
Subway: Retrieval
CMP-150 (SMG): Found on some guards.
DW-P5 (SMG): Found in the only open storage crate after you have gone through the parking garage.
Rooftops: Escape
Jackal (Heavy): Found on the sniper if you did not shoot it off the building. The easiest way is to put away any weapon you have (Up) and use disarm (RB).
M60 (Heavy): Found once you get to the fire doors. Go past the fire doors and lock pick the door. It should be standing atop an artillery box next to the guard.
Mansion: Infiltration
Magsec 4 (Pistol): Found on all guards at the beginning of the level.
Viblade (Close Combat): Found once you get in the mansion. It is standing on a pedestal in the middle of the laser maze.
Laboratory: Rescue
KSI-74 (Assault): Found on almost all blue guards.
Magnum (Pistol): Found on the yellow suited guards that come once the alarm is triggered.
River: Extraction
Rocket Launcher (Heavy): It is recommended to get this weapon when in Co-Op mode, as it is quite difficult to get. Once you get outside, open the gate and kill the guards. On the hovercraft that you take, press Y when by the gunner to switch for another heavy weapon (M60 and Plasma Rifle only).
Trinity: Infiltration
Combat Shield (Close Combat): Found on one of the guards after you picked up Dr. Carrol. There are two guards once you find the round walkway the leads to the lower level.
Hawk Boomerang (Thrown): Found in one of the boxes in the beginning of the level. This is easier to get after you have picked up the X-Ray goggles in the weapon cases to the left once you start.
Trinity: Escape
Psychosis Gun (Pistol): Found on most scientists throughout the level.
Jungle: Storm
RCP-90 (SMG): You can find this either on the assaulting guards or atop of boxes by the left wall. Try using this on that level every time you play. Secondary (RB) makes an outline of red around your enemy, with the lost of some accuracy.
Temple: Surveillance
Frag Grenade (Thrown): Found on some of the guards. This may be difficult to find.
Laptop Gun (Assault): Found on one of the two guards after you have gone down two levels. If one of the guards plants one, reprogram and pickup. It should say reprogram once you get close to it.
Multimine (Thrown): Found on the guard that is either on the water bridge, or around the corner after it.
Plasma Rifle (Heavy): Found at very end of level on any of the Phantoms.
Outpost: Rescue
FAC-16 (Assault): Found in one of the weapon cases after you rescue Jonathan.
Flash Bang (Thrown): Found on one of the guards in the room before you go through the double keypadded door.
Bridge: Assault
Shockwave (Heavy): Found on the fallen Carrington sniper once you go to aide Jonathan's team.
Super Dragon (Assault): You may have found this gun before. Found on some of the guards on the bridge.
X-ray goggles and Hawk in Mission 7
At the beginning of Mission 7, before or after you kill the two brothers, there are four lockers on the right wall of the side of the bridge that you start at. If you are looking directly across the bridge and turn 90 degrees, you will see four lockers on the wall. In one of them is a pair of X-ray goggles. If you look around in the wooden crates on the side that you started on, there should be a new weapon called the Hawk. It is a disk that you can throw and slice people with.
X-ray goggles in Mission 10
Get to the second level of the stage. Once you enter the corridor that has the two traps, instead of continuing past the traps, turn around and enter the door behind you. Inside there should be two guards. On a crate near one of the guards will be the X-ray goggles.