Bank: Invisible Laser Beam

To avoid detection by the invisible laser trip wire in the entrance of the vault, closely examine the entrance with your thermal goggles on. Then, use your OCP to disable the laser emitter and walk out of the vault. By doing this, you can leave without sounding the alarm.

Bathhouse: Alternate Shetland Death

At the end of the level, Shetland and Sam will be on top of a roof with their guns pointed at each other. After a short conversation, Shetland will put his gun away and say 'You wouldn't shoot an old friend'. You are given a choice, shoot or put your gun away. If you shoot, Shetland will stumble backwards and the intermission sequence for the level's ending will play. However if you put your gun away, Shetland will quickly pull his gun out and point it at Sam. Sam will duck his weapon and stab Shetland in the stomach before throwing him. This will then start the same ending sequence.

Bathhouse: Finding The Bombs

After going through the gate when chasing Shetland, the first bomb is directly to the left of the gate that you enter. Go left through a little crevice and you should see a red light flashing. Go to it and disarm it. When you do that, one of Shetland's gaurds will walk up the stairs. Kill him. To get to the second bomb, go up the stairs. Turn left then turn right and look straight ahead. You should see another red flashing light down below the walkway. Hop over the ledge of the railing and disarm the second bomb. When you are done disarming the bomb, jump on to the railing and pull yourself up. Two guards will be to your left, walking on the walkway. They will probably hear you; get ready to kill them. It is fairly difficult to kill them without losing a lot of life, or at least dying. After you kill them, go down the walkway to the back wall. About halfway you will see another red flashing light. Jump across the little gap and disarm it. A guard will come through the back door right when you disarm the bomb. Kill him, then go through the door and meet Shetland. You will then have to make a critical choice; note: pull the trigger. It would be a good idea to quicksave the game whenever you disarm and kill the guards.

Bathhouse: Splinter Cell Reference

You must go through the warm baths at one point in the level. There are two guards here. Interrogate one of them and he will tell you that Shetland's elite guards have thermal goggles. He will also add that they will not do much good in steam, because steam is not fog, as in an abbatoir. This is a reference to the original Splinter Cell game, in which Abbatoir is a level.

Catching Shetland

Have your sniper zoomed-in on the guard. When there is a fight, shoot, run, and catch Shetland. Then, end the mission.

Catching Shetland

Have your sniper zoomed-in on the guard. When there is a fight, shoot, run, and catch Shetland. Then, end the mission.

Elite Mode

Complete the game succesfully. Elite mode starts the game with only the knife and unloaded guns.

Hokkaido: Splinter Cell Reference

After you scan Milon Nedich's liscence plate and enter the building, you will overhear some guards talking about ninjas. One will be telling the other that he was stationed on an oil rig and that it was attacked by a ninja. This is a reference to the first Splinter Cell in which Sam is the ninja.

Hundred percent rating

In order to get a hundred percent rating on any mission, you must complete the level with the following statistics:

Alarms sounded: 0
Bodies Found: 0
Civilians killed: 0
Enemies killed: 0
Times Identified as intruder: 0

I-sdf Base: Metal Gear Solid Reference

When you get to the lower floors in the I-SDF base, interrogate a guard. Sam will ask him about his LTL (less-than-lethal) weapon. The guard will tell Sam that the ammunition is some kind of electric round. Sam asks where he can find some. To this the guard replies: 'It's not like you can shake me, and make my ammo drop on the floor'. This is a reference to the Metal Gear Solid games, in which you can do just that.

I-sdf Base: Splinter Cell Reference

You can overhear a couple of guards talking in the main hall. One will say something about how guarding the place is just like guarding the CIA HQ; nobody would break in there. This is a reference to the original Splinter Cell, in which you must break into CIA headquarters.

Ledge Grab

In order to do a better ledge grab, press A, then when the spy puts his legs up on the thing he is hanging from, press Forward while tapping A.

Lighthouse: Alternate Way To Retrieve The Radio Data

During the mission you will have to overhear some data being said on a radio transmission by a guard. If you fail to do
this, you can just find the data in a filing cabinet next to the radio.

Movie Trailer

Successfully complete the Lighthouse mission in solo mode.

Penthouse: Bouncing Guard

On the ground floor after you have knocked out two guards (the one who is repairing the elevator and the other one that is talking to him), put one or more of the guards in the elevator with Sam. Sam must turn on his night vision and press the button to go to the top floor. Watch the guard's body bounce around like popcorn.

Sneaking

If you move around with your gun drawn, the noise meter will not move. This is very useful when sneaking up on someone quickly.

Unlock all levels

In the Solo / Co-Op Menu: Press and hold the "Left' and "Right" Triggers.