Map Locations
Enter the following password into the in-game computers.

Password Effect
www.whattheydonotwantyoutoknow.com Weapon, health, armor, vehicle, pigeon, ramp/stunt, and entertainment locations
Cell Phone Passwords
At any time during the game, pull out Niko's phone and dial these numbers for the desired effect.

Please note that cheats will affect missions and achievements.

Password Effect
482-555-0100 Restore health, armor, and ammo
362-555-0100 Restore armour
486-555-0100 Get a selection of weapons
486-555-0150 Get a different selection of weapons
267-555-0100 Remove wanted level
267-555-0150 Raise wanted level
468-555-0100 Change weather
359-555-0100 Spawn an Annihiliator
938-555-0100 Spawn a Jetmax
625-555-0100 Spawn an NRG-900
625-555-0150 Spawn a Sanchez
227-555-0100 Spawn an FIB Buffalo
227-555-0175 Spawn a Comet
227-555-0147 Spawn a Turismo
227-555-0142 Spawn a Cognoscenti
227-555-0168 Spawn a SuperGT
948-555-0100 Song information

Unlockables
Unlockable How to Unlock
Annihilator Helicopter Kill all 200 Flying Rats
Rastah Color Huntley SUV Complete 10 Package Delivery missions
Remove Ammo Limit Get 100% completion
Friendship Bonuses
By gaining friendship with the following people can benefit you in many ways.

Unlockable How to Unlock
Chopper Ride (He will pick you up in his helicopter) Gain 70% Friendship with Brucie
Extra Help (A car of gang members will be sent to help you out) Gain 60% friendship with Dwayne
Boom? (Call Packie for him to make you a car bomb) Gain 75% friendship with Packie
Discount Guns (Buy weapons at a cheaper price from Lil Jacob) Gain 60% friendship with Little Jacob
Free Ride (Call for a taxi) Gain 60% friendship with Roman
Remove Up to 3 Wanted Stars (Call Kiki and select "Remove Wanted") Get 80% Relationship Status with Kiki
Health Boost (Call Carmen and select "Health Boost") Get 80% Relationship Status with Carmen
50% off for all Clothing Stores Get 80% Relationship Status with Alex

Trophies
Complete each condition to get the allotted Trophies. There are 42 Bronze Trophies, 5 Silver Trophies, 3 Gold Trophies, and 1 Platinum Trophy.

Unlockable How to Unlock
Off The Boat (bronze) You have completed the first mission
You Got The Message (bronze) You delivered all 30 cars ordered through text message
Full Exploration (bronze) You unlocked all the islands
Impossible Trinity (bronze) You completed the mission "Museum Piece"
Half Million (bronze) You have amassed a fortune of $500,000
That’s How We Roll! (bronze) You unlocked the special ability of Brucie’s helicopter ride.
Order Fulfilled (bronze) You completed all 10 Exotic Export orders
Fed The Fish (bronze) You completed the mission "Uncle Vlad"
Sightseer (bronze) You have taken all variations of the helicopter tours of Liberty City
It’ll Cost Ya (bronze) You made a taxi trip from one island to another without skipping
Cleaned The Mean Streets (bronze) You caught 20 criminals through the police computer
Manhunt (bronze) You completed the most wanted side mission
Lowest Point (bronze) You completed the mission "Roman’s Sorrow".
Chain Reaction (bronze) You exploded 10 vehicles in 10 seconds
Warm Coffee (bronze) You were invited into your girlfriend’s house
Courier Service (bronze) You completed all 10 package delivery jobs
Retail Therapy (bronze) You unlocked the special ability of buying guns from Little Jacob.
Wheelie Rider (bronze) You completed a 500 foot wheelie on a motorbike
Gobble Gobble (bronze) You got a turkey in 10-pin bowling
Finish Him (bronze) You completed 10 melee counters in 4 minutes
Genetically Superior (bronze) You came first in 20 singleplayer street races
Driving Mr. Bellic (bronze) You unlocked the special ability of Roman’s taxi
Rolled Over (bronze) You managed 5 car rolls in a row from one crash.
One Hundred And Eighty (bronze) You scored 180 with 3 darts
Gracefully Taken (bronze) You completed the mission "I’ll Take Her"
Teamplayer (bronze) You killed 5 opposing team members
Walk Free (bronze) You successfully lost a 4 star wanted rating
No More Strangers (bronze) You’ve met all the random characters
King of QUB3D (bronze) You beat the high score in QUB3D
Pool Shark (bronze) You beat a friend at pool
Assassin’s Greed (bronze) You completed all 9 assassin missions
Cut Your Teeth (bronze) You were successfully promoted up a rank in multiplayer
Join The Midnight Club (bronze) You won a multiplayer race without damaging your vehicle too much
Top The Midnight Club (bronze) You won 20 different multiplayer standard races
Dial B For Bomb (bronze) You unlocked the special ability of Packie’s car bomb placement.
Under The Radar (bronze) You flew under all the main bridges in the game
Top Of The Food Chain (bronze) You successfully killed 20 players with a pistol in a deathmatch
That Special Someone (bronze) You completed the mission "That Special Someone"
Taking It For The Team (bronze) You were on the winning team in all multiplayer team games
Fly The Co-op (bronze) You completed "Deal Breaker", "Hangman’s NOOSE" and "Bomb da Base II" in time
Auf Wiedersehen Petrovic (bronze) You won in all variations of multiplayer games
Let Sleeping Rockstars Lie (bronze) You killed a Rockstar in multiplayer
One Man Army (silver) You survived a 6 star wanted level for a full 5 minutes
Dare Devil (silver) You completed all the unique stunt jumps
Endangered Species (silver) You collected every hidden package in the game
Liberty City (5) (silver) Your friends all like you above 90%
You Won! (silver) You have completed the story
Wanted (gold) You achieved the highest personal rank possible in multiplayer
Liberty City Minute (gold) You finished the story in less than 30 hours
Key To The City (gold) You completed GTA IV to 100%
Taking A Liberty (platinum Sorry for taking liberties with your time! (acquire all other trophies)