Successfully complete the game on the indicated difficulty to unlock the corresponding cheats and bonuses at the "Extras" menu. Note: Enabling the "Infinite Ammo", "Instagib", or "Invincibility" cheat options will prevent Ego points and achievements from being earned.
- Concept Arts: Easy difficulty or higher
- Development Timeline: Easy difficulty or higher
- Duke 3D Freeze Ray (freeze ray fires bouncing ice projectiles): Normal difficulty or higher
- Duke Sound Board: Easy difficulty or higher
- Game Speed (adjust game speed): Normal difficulty or higher
- Grayscale Mode (black and white graphics): Normal difficulty or higher
- Head Scale (adjust head size of enemies and NPCs): Easy difficulty or higher
- Infinite Ammo: Normal difficulty or higher
- Instagib (enemies killed with one shot and always gib): Normal difficulty or higher
- Invincibility (no damage from bullets or explosions): Normal difficulty or higher
- Mirror Mode (graphics are mirrored horizontally): Normal difficulty or higher
- Movies: Easy difficulty or higher
- Screenshots: Easy difficulty or higher
- Triptych Office Photos: Easy difficulty or higher
Successfully complete the indicated multiplayer weapon challenge to unlock the corresponding accessory in the changing room:
- Backwards Baseball Cap: Get 250 kills with the Shotgun (Burger Face III).
- Baseball Cap: Get 75 kills with pipe bombs (Splatter King III).
- Brain Sucker: Get 250 kills with the Enforcer (Laser Seeking Missiles III).
- Canadian Flag Logo: Get 75 kills with the Garter Pistol (Tiny But Deadly III).
- Cheese Hat: Get 250 kills with the Ripper (Swiss Cheese III).
- Detonator Logo: Get 250 kills with the Rocket Launcher (Boom Goes The Weasel III).
- Hoplite Helmet: Get 75 melee kills (Punchy McPuncher III).
- I Shot Stupid Logo: Get 250 kills with the Railgun (Right In The Eye III).
- Jester Hat: Get 75 kills with trip mines (Watch Your Step III).
- Military Hat: Get 250 kills with the Pistol (Size Doesn't Matter III).
- Retro Duke Logo: Get 250 kills with the Devestator (Meat Grinder III).
- Ski Goggles: Execute a frozen player 75 times (Ice To See You III).
- Tie-Dye Shirt: Get 250 kills with the AT laser (Medium Rare III).
- Uncle Sam Hat: Stomp on 75 enemies (Pee Wee Vermin III).
- Wolf Logo: Get 75 kills with Steroids (Roid Rage III).
- WTF Logo: Get 75 kills with exploding barrels (Smile You Son Of A Bitch III).
Reach Level 40 in Multiplayer mode to unlock Overdrive mode. In this mode, all points earned are doubled with the exception of challenges. You will also get 20 points each time an enemy is damaged.Microwaved rat
In Chapter 2: "Damn! It's Late...", there is a room with a microwave. Directly under the microwave is a cupboard that can be opened to find a rat. You can pick up the rat and put it in the microwave. Note: This room is also shared with the Duke Nukem Fanboy.300 reference
Duke will say "Tonight, you dine in Hell" after a kill in the "Vegas In Ruins" chapter. This is a reference to 300, when Leonidas says "Tonight, we dine in Hell!"Christian Bale reference
In Chapter 2: "Damn! It's Late...", after walking off the set, you will see an actor yelling at someone. He says things like "Do you want me to trash your mics? DO YOU?" and "You're a nice guy, you really are but you're a f**king amateur". This is a reference to when Christian Bale freaked out on the set of Terminator: Salvation.Dead Space reference
In "The Hive" chapter, after you tickle the first door, turn to your left, and walk forward. Crouch to get under the bridge, and you will see a dead EDF Soldier with Isaac Clarke's signature engineer helmet.Halo reference
At the start of the "Vegas In Ruins" chapter, before you enter the building, there is a van with weapons. The armor in the van is the same from Halo, other than the Nukem insignia on the helmet visor.Inception reference
In the "Duke Nukem's Titty City" chapter, enter the room where you can microwave the popcorn. Look on the desk where you can use the security camera, and you will see a spinning top, like the one Leonardo DiCaprio uses in Inception.Mortal Kombat reference
In the Duke Nukem soundboard, there is an entry called "Fatality". When you select it, Duke says "Duke wins, Fatality."Starship Troopers reference
After killing some enemies, you will hear Duke say "I'm from Las Vegas, and I say kill 'em all!". This is a reference to Starship Troopers when Johnny Rico says "I'm from Buenos Aires, and I say kill 'em all!".Tommy Tutone reference
In the bathroom in the "Duke Nukem's Titty City" chapter, above one of the urinals is some grafitti that reads "Jenny - 867-5309". This is a reference to the Tommy Tutone song of the same name.Easy "Air-Duke" achievement
In the "Duke Nukem's Titty City" chapter, go to the game room at the back of the club, and play a game of air hockey. Instead of focusing on scoring, try defending your goal as good as possible. The rest will happen by accident since the opponent is very weak.Easy "Balls Of Steel" achievement
Pinball games are located in different locations throughout the game. The first pinball game can be found in "The Duke Cave" chapter. While playing the pinball game, to speed things up, you should get at least a x2 multiplier without wasting a ball. Hold the top left flipper, and bring the ball up there. Quickly release the flipper, and let it hit the three panels. If the ball is getting too far on the right side, you can tilt the table to the left. Keep repeating this method. Do not use the tilt ability more than once every five seconds. If you use it too often, you will lose control over the flippers.
The first helmet is at the very beginning of the "Vegas In Ruin" chapter in the back of a vehicle. The second helmet is at the beginning of "The Hive" chapter. Turn left after going through the first alien hole to find it. The third helmet is found in the "Blowin' The Dam" chapter. After planting the first bomb and fighting two octopuses, swim to some debris to your left to find it and get the "Bucket Head" achievement.
In Part 2 of "The Forkstop" chapter, you will reach a large area where you need to turn the power on. After killing some waves of enemies, use the forklift, and climb the wall to your right. Grab the heart barrel, and go to the other side. Place the barrel on the blue heart drawing on the ground to open the secret room and get the "Companion Barrel" achievement.
There are 28 Ego Awards. There are a couple extra rewards that are gained automatically by playing through the story. If you get all Ego Awards during your first playthrough, you will get the "I Am All That Is Man" achievement in the "Blowin' The Dam" chapter.
In "The Shrunk Machine" chapter, near the beginning, after entering the first large room, straight ahead across the room are some double doors. There is a calendar on the wall behind the double doors. Look at all pages to get the "I Need A Date" achievement. There is another calendar in Part 2 of "The Forkstop" chapter on the wall in one of the rooms.Easy "Party Animal" achievement
In the "Duke Nukem's Titty City" chapter, drink all nine beers in the strip club to get the "Party Animal" achievement. One beer is behind the locked door. The code is "4768". Get all the other items that are required to proceed with the chapter. After giving the items to the stripper, you can enter the last room.
In the "Blowin' The Dam" chapter, kill all 15 catfish to get the "Pescaphobe" achievement. Turn on your Duke Vision to detect them much easier.
At the beginning of "The Duke Dome" chapter, you will get an infinite amount of explosives when entering a building. Throw a trip mine directly on one of the enemies to get the "Sticky Bomb Like You!" achievement.Easy "Sunday, Black Sunday" achievement
In the "Duke Lives" chapter, at the very beginning of your first fight, you will see a blimp in the background. Keep shooting it until you get the "Sunday, Black Sunday" achievement.Easy "Turd Burglar" achievement
Poop can be found in toilets. There is some poop in the toilets in the room where the game begins ("Duke Lives" chapter). Grab poop from a toilet and throw it to get the "Turd Burglar" achievement.Steam achievements
Successfully complete the indicated task to unlock the corresponding achievement. To view your achievements and stats in Steam, select "Community", "My profile", "View all my games", then the game and view stats.
- A Good Dam Fight: Defeat the Battlelord on the Hoover Dam.
- Air-Duke: Win air hockey with a score of 7-0 in the strip club.
- Annihilation: Kill 100 aliens.
- Balls of Steel: Earn a 1,000,000 pinball score in SP.
- Baron von Nukem: Shoot down 20 alien fighters.
- Beating the One-Eyed Worm: Defeat the Energy Leech.
- Big Guns, Big Ships: Blow up 5 enemy gunships or dropships.
- Bucket Head: Find all 3 helmets in the SP campaign.
- Call Waiting: Listen to all phone messages.
- Come Get Some: Complete the SP campaign on Hard Difficulty.
- Companion Barrel: Unlock the secret closet at the end of the Forkstop.
- Damn, I'm Good: Complete the SP campaign on Insane Difficulty.
- Dead Useful: Kill 10 aliens with environmental explosives.
- Drawrings: Doodle something on the whiteboard in SP.
- Duke Angry, Duke Smash!: Kill 15 aliens with melee attacks while on steroids.
- Extermination: Kill 50 aliens.
- Flagon of Chuckles: Drink a beer in SP.
- Fork the Pork: Kill 6 aliens with the forklift.
- Freeze Well!: Kill 15 frozen aliens.
- Full Body Tourettes: Get knocked down 10 times.
- Gunslinger: Carry the gold pistol through the whole SP campaign.
- He's Got a Hologram!: Use a Holoduke in SP.
- Hippy-Stomper: Foot stomp 12 aliens.
- I Am All That Is Man: Discover all ego cap rewards.
- I Need a Date: Look at every page of a calendar in SP.
- I Need a Towel: Get hit by 10 Pregnator bombs.
- Judge, Jury, Executioner: Execute 20 aliens.
- Juiced: Take steroids in SP.
- Let's Rock: Complete the SP campaign on Normal Difficulty.
- Lots of Whacking: Win a game of Alien Abortion in the strip club.
- Natural Disaster 3x: Kill 3 aliens at once.
- Nobody Likes a Whiner: Knock out the talent at the talk show.
- Noms: Eat 10 pieces of food during the SP campaign.
- Not Bad for a Human: Defeat the Alien Queen.
- Nuclear Devastation: Kill 250 aliens.
- Octacide: Defeat the Octaking.
- On the Noggin': Kill 30 aliens with headshots.
- One-Eyed Freak: Defeat the Cycloid.
- Party Animal: Drink all of the beers in the strip club.
- Pescaphobe: Kill all of the catfish in the underwater level.
- Piece of Cake: Complete the SP campaign on Easy Difficulty.
- Pit Champion: Defeat the Battlelord in Las Vegas.
- Road Rage: Kill 15 aliens with the monster truck.
- Special Thanks: Watch the credits all the way through.
- Sticky Bomb Like You!: Put a Trip Mine on a live alien.
- Substance Abuser: Drink beer while on steroids or vice-versa in SP.
- Sunday, Black Sunday: Shoot down the blimp above the stadium.
- Tosser... in the Literal Sense: Kill 10 aliens with tossed objects.
- Trapper: Kill 10 aliens with trip mines.
- Turd Burglar: Find and steal a piece of poo.
The following achievements require "The Doctor Who Cloned Me" bonus downloadable content:
- Bubble Buster: Kill 10 expanded enemies with melee attacks.
- Threesome: Kill 3 enemies within 3 seconds with the Impregnader.
- Bloody Red Rover: Kill 30 enemies with the moon rover.
- Scientits: Earn a 1,000,000 pinball score on the Scientits pinball machine.
- Heart to Heart: Finish Doctor Proton.
- Another Piece of Cake: Beat The Doctor Who Cloned Me campaign on Easy Difficulty.
- Let's Rock Out: Beat The Doctor Who Cloned Me campaign on Normal Difficulty.
- Come Get A Little More: Beat The Doctor Who Cloned Me campaign on Hard Difficulty.
- Damn, I'm REALLY Good: Beat The Doctor Who Cloned Me campaign on Insane Difficulty.
- I Am All That Is Man - Again!: Discover all Ego cap rewards in The Doctor Who Cloned Me campaign.