Party mission:
Go to the underground UNATCO ruins on Liberty Island. Take the U.N. flag from 
near the beginning of the ruins and find your way to to James Manderley's office 
from the first Deus Ex. Hold the flag while flushing the toilet inside the bathroom to 
play the programmer's party mission. 

Thief 3 preview:
Successfully complete the game to unlock a preview of Thief 3 in the "Extras" 
option. 

Seattle: Entering apartments:
In the Emerald Suites in Seattle, there are several ways to enter the penthouse, 
Dr. Nassif's apartment, and apartment 2226 in which the lawyer who the owner of 
Club Vox asks you to kill, lives. If you have several Multitools, use them to disable 
the power in the elevator shaft. From there you can access a vent shaft that leads 
to the Minister Of Culture's penthouse. At the end of the hall (not the penthouse), 
you can find a Multitool under the staircase. Use it to disable the power to the 
alarms of apartment 2226 and you can break the glass sunroof to gain entry. You 
can also use the Glass Destabilizer and save your Multitool. However, be sure to 
have an EMP or Scrambler Grenade for a Security Bot on the roof. Elsewhere in 
the suites is an easy to find vent shaft that leads into Dr. Nassif's apartment. 

Free Biocanister:
Find the mutant and get a sample before bartering with the Omar in Seattle to get 
a 50% discount and a free Black Market Biocanister. It is in the basement of Club 
Vox in Upper Seattle. 

Assassin Pistol:
This is a pistol with a zoom function instead of a flashlight, and also seems to be 
more powerful. It is a good substitute for a sniper rifle. It is inside the Nine Worlds 
Tavern in Trier Germany. Once inside, there is a part where you will see stairs that 
lead up to a closed door and down into a bar. Go up, pick the lock, and enter. You 
will meet the Omar here if you can find their contact. In one of the corners under 
some junk (you must throw it around as it hides the stash), you will find the 
weapon along with some other assorted items. 

Dragon Tooth Sword:
This is an energy sword that hurts very much. Go inside JC's sanctuary. It is on 
top of a bookshelf when you enter the first remembered area (Maggie Chow's 
apartment, Hong Kong, from the first game).

Explosive crates:
Use explosive crates whenever you can to blow up cameras, beams, turrets and 
almost anything else that gets in your way. 

Hellfire Boltcaster:
This is a boltcaster that makes enemies burst into flames instead of being knocked 
out. Its inside the Nassif greenhouse and is slightly difficult to get. Go through the 
warehouse and into the office, then make a left in the hall (away from hydroponics 
control). Then, save the game when you get to the balcony save (so you do not 
have to run all the way around). Carefully jump to the beams sticking out on the 
other side of the rail. Then, jump to the ledge to your right. It is small, but you can 
stand on it. Use the outcropping window as a foothold to jump up onto the balcony 
above you, then go through the vent shaft. In this room you will find the weapon in 
the corner amidst some junk. 

Proximity mines:
You can use the alternate fire of the proximity mines to set a timer. This is also 
useful for blowing up beams and turrets that are not triggered regularly.

Red Greasel Hunter:
This is a pistol with a red flashlight. In Lower Seattle, you can find this under the 
sewer grate in front of the Greasel Pit Bar. It is lying near or under an Omar 
corpse. Watch out; you will have to kill two Karkians to get it. If you do not like 
close encounters, once they start chasing you, climb out and drop a concussion 
grenade on them.

Toxic gas:
Shoot cylinders that contain toxic gas to fill a the room and kill anyone within the 
blast radius. Also, if you have the strength modification you can pick up these 
cylinders and throw them into a desired room. This is a good way to kill guards 
without being seen.

Toxin Blade:
This is a knife that does excellent damage and stuns your opponents with the first 
hit. In Upper Seattle within the Emerald Suites building, you can find the Toxin 
Blade. It is in the apartment next to Dr. Nassif's under the pillow on the bed. There 
is one hostile in the apartment.

Widowmaker:
This is a SMG that fires Spider bots instead of flash grenades at the expense of an 
entire ammo clip. It can be found in the Cairo Archology on your second visit. 
From floor 107, near the Templar recruiting booth and Tarsus academy, go down 
the ramp into the maintenance area. Make a left and look on the right wall for an 
opening. Crawl in, make a left, then look left for another opening. Push the junk 
out of your way and enter the little hiding place. It is near a corpse.

Save health and energy:
Using the Active Black Market Biomod that allows you to control an EMP Armed 
Spybot next to an Engineering Bot that refills your Bioelectricity. This allows you to 
have an infinite range. You can destroy all electrical equipment and bots in the 
vicinity without having to use energy cells or risk health.

Take out weapon on ladder:
When you climb a ladder, you will automatically put away your weapon. Press B to 
take it out while still on the ladder.

Mega-Jump 
Position yourself a few feet from a low lying object (stairs [recommended], seat of 
a couch, non-movable bench, or others about the same height) and start running 
towards it. Just as soon as you start to walk over it, jump. You should jump 2-3x 
as high as usual. 

Have bot powers:
Note: Save the game before doing this. Get the Bot Domination Biomod. It helps 
to upgrade it to level 3. Next, find a bot and attempt to dominate it. Find a door or 
entrance that leads into another zone via a loading screen. Let the timer count 
down and time your exit just as you are going into the bot's peripheral vision. The 
screen should stay white upon your exit. If you did not time it correctly, you will be 
booted to the Xbox menu. Now when you are in the area you exited to, all of your 
inventory items will be gone, but you will have the bot's weapon. Note: The 
Spiderbot's weapon is null and will not do any damage.

Emerald Suites Penthouse:
At the Greasel Pit bar in Lower Seattle, you can talk to the man who owns the 
penthouse at Emerald Suites. Talk to him and agree to be his "chamber boy". He 
will give you the key. He warns you to stay in the kitchen "or the bot will take 
offense". However, it is just a spider bot and can be taken out easily. From there, 
you can hack the security terminal to turn off the laser grid, then go upstairs and 
hack another to open his vault. From in there, you can find all sorts of items , 
including an Energy Blade and the evidence the WTO wants you to find for a 
secondary mission.

Free Pilot:
You will need some Multitools and the Neural Interface Biomod to do this trick. In 
Lower Seattle, there is a bar called the Greasel Pit. Look around until you find an 
empty room with a Holocomm inside. A girl named Ava Johnson will start talking to 
you, saying that the WTO is holding her captive. She wants you to help her 
escape. Go to the WTO Air Terminal and to that elevator that two guards are 
standing by (you will have the keycode by now). Wait until the bot is not looking 
then move straight up the stairs. Go all the way down the walkway. To your right 
is a building guarded by a camera. Sneak past the camera and unlock the door 
with a Multitool. Go in, hack the security computer, turn off the turret, then sneak 
back up the walkway. To the left there is a bot guarding another building. When it 
is facing away from you, drop down and crouch behind the boxes or the turret. 
Wait for the correct moment to make a dash for the door. Once inside, deactivate 
the second turret, but do not leave just yet. There is a vent in the room that you 
can use a Multitool on. Hop in, move to the right, and get the other Multitool. Then, 
go back and head up the vent. You can turn on the Pilot Beacon from inside this 
room. Head back down the vent. There are now more guards outside looking for 
you. It is slightly difficult to get to the helipad from here, Try waiting until the bot is 
not looking and make a mad dash for it. Once you talk to Ava, she will give you 
free transportation for the rest of the game. It is difficult to do this, but is well 
worth it as you will have a lot more money to spend on other things. Note: If you 
are working for the WTO they will get mad at you for doing this, but will let it slide.