Duke Nukem is a legendary American hero who has defended Earth from various evildoers over a dozen times, emerging triumphant over every threat. He is the flagship character for an entire franchise named after him.
Though little is known of Duke's early life other than his birth date, it is known that he later joined the US Army and served under General Graves as part of the US peacekeeping force in Beirut during the Lebanese Civil War. He later became friends with Dylan, with Dylan mentioning that they took part in an undisclosed mission on Beirut.
Duke later left the Army, but little is known of the time between this and the events of the first Duke Nukem game, where he is hired by the CIA to save Earth from the evil machinations of Dr. Proton.
After defeating Dr. Proton and putting an end to his schemes, Duke becomes the hero of Earth. While presenting a book of his during a talk show, Duke is kidnapped by alien race known as Rigelatins. These aliens planned to eventually take over Earth, but discovered that Duke may be a threat, so they decided to deal with him on their own planet. This ordeal ended with Duke crushing Rigelatin leaders and escaping their planet.
Duke returns to Earth only to encounter another race of alien invaders, which came to capture the women of our planet. Duke defeats this threat by destroying a large portion of their invasion force, killing their Cycloid Emperor and Queen. He is hailed as a hero for this superheroic feat, and goes on to become known worldwide as a true hero of Earth.
In the peaceful years after the first alien invasion, Duke used his hard-won fame to its fullest, becoming a successful businessman and celebrity multimillionaire. He took up residence in Las Vegas, Nevada, managing franchises like Duke Burger, a successful restaurant chain; and the Lady Killer Casino. He has also appeared to be the man most desired by many beautiful women across Las Vegas and possibly the world. It is not entirely certain, but possibly it was during this time that Duke encountered many other enemies, such as Mech Morphix, Zorgonites, and, using time travel, battled other alien forces in both past and future.
Duke's time has come again many years later, when aliens returned, seemingly peacefully. However, they quickly showed their true colors, and started to kidnap women, also launching a full-scale attack on Duke with their mothership. Fighting his way through war-torn Nevada, where the aliens started their new invasion, Duke killed the new alien queen in Las Vegas, greatly helping the allied Earth Defense Forces in securing Vegas from the aliens. He also helped the EDF to destroy the Hoover Dam, which was providing power to a massive portal used to warp in alien troops for their invasion. This resulted in an infuriated US President calling down a nuclear strike on Duke's position. However, the President was killed by the new Cycloid Emperor who was in turn killed by Duke. Fortunately, Duke managed to escape the nuclear strike just in time, being rescued by an EDF dropship with his old commanding officer General Graves on board.
With the President dead, Duke announced he was going to run for office. Unfortunately, he was kidnapped by a resurgent Dr. Proton and taken to Area 51. Proton, who had been brought back to life by heavy cybernetic augmentation, told Duke he was going to use clones of Duke Nukem to destroy the aliens once and for all on the moon, where they were staging their invasion, and ruin Duke's vaunted reputation. Proton told Duke that though the alien invasion had been stopped in Nevada, they were free to regroup and begin an even larger invasion of Earth if their main base on the moon was not destroyed.
Though Dr. Proton tried multiple times to kill Duke, Duke killed Dr. Proton himself by ripping his head off, killing Proton for good. Duke also encountered his friend Dylan, who he thought had died in an alien ambush in the Hoover Dam; he also encountered General Graves. The three escaped Area 51 when it was destroyed, with Proton's entire army of cyborgs and Duke clones perishing in the flames. After escaping Area 51, Duke and Dylan found an old teleporter that would take them to the moon, where they would stop the second alien invasion. With Dylan maintaining the portal, Duke stepped through.
Braving the lunar surface, Duke found the true leader of the invasion: a massive alien empress. Duke killed the empress and ended the alien invasion once and for all, while also rescuing many beautiful kidnapped women in the process.
Befitting an All-American hero, Duke is supremely physically fit and completely confident in himself and his abilities, accomplishing sometimes superhuman feats through sheer aggression and ruthless combat skills. He is quick to a wisecrack and frequently speaks his mind, but cares little for his detractors, as he knows his heroic physical accomplishments speak for themselves.
Duke is 6"4" and is able to bench press at least 600 lbs. He is strong enough to easily overpower many inhuman enemies at melee combat, including cyborg Dukeinators and raging alien Pig Cops; his Mighty Boot attack in Duke Nukem Forever has been shown to decapitate enemies; and he has also been shown to rip a head completely off its body using brute strength alone. He is tough enough to trek unprotected through the hostile surface of the moon, as seen in the new Duke Nukem Forever DLC. Duke is also highly skilled in using various types of firearms and explosives, able to wield nearly everything from contemporary weapons like pistols, assault rifles and pipe bombs all the way to experimental human or outright alien weapons like the Shrink Ray or alien Enforcer Gun.
Duke is never seen without his signature sunglasses, red tank top, and blue jeans; he is also outfitted with a black combat harness that contains many utility pouches for extra ammo or explosives. His hairstyle is the constant platinum blond, military-style haircut seen since his debut. Finally, he is rarely seen without his favorite sidearm, the gold-plated M1911, marked with Duke's symbol, the Nuke Logo.

Mighty Foot
The Mighty Foot (sometimes called Mighty Boot or Kick) is Duke's signature "weapon". Duke always has access to this means of attack, and can even deliver a kick while holding another weapon. The Mighty Foot is named Sandal Foot in the add-on Duke Caribbean: Life's A Beach, as it is a sandal on Duke's bare feet.
Duke Nukem's one and only melee attack, it consists of a swift foot planted squarely into the enemy's face.
Duke's Mighty Foot is a black combat boot and it is said by Duke himself to be size 13.
However, this attack's usefulness extends far beyond attacking enemies. It can be used to break glass windows, vents, metal bins and so on.
A useful feature of the Mighty Foot is that it can be used even while holding another weapon, via the "Quick Kick" key. Tapping this key will deliver a swift boot without having to switch weapons. However, the numbers of kicks the player can do is noticeably slower as opposed to when the player is using the Mighty Foot as a singular weapon.
Quite clearly, this attack has no ammo and is always available to use.
The damage of the Mighty Foot increases with the use of Steroids.
The actual boot and blue jeans were provided by Robert Atkins who wore them into work at 3D Realms. Stephen Hornback then photographed Rob's leg in various positions in Stephen's office. Stephen then cut out the graphics, added them to the build engine's graphics, and Todd Replogle coded in a great kick in the "foot".













Pistol
The Pistol is Duke's trademark, and (arguably) his weakest weapon. Duke has used this weapon in almost each game since Duke Nukem 3D. It is usually accurate and shoots fast, but is not automatic and needs to be frequently reloaded with its low magazines. The Pistol has several variations in Duke Nukem games, like the Desert Eagle or the M1911 and became one of Duke's most symbolic guns.
The Pistol is a dark grey handgun, mostly resembling a Glock 17. It is invariably the first weapon the player will use/find in each game.
The Pistol has a high rate of fire, but each of its magazines only hold 12 rounds, meaning it needs to be reloaded, which takes time. It also has a high accuracy and can be used to shoot switch buttons in the game.
Even though they do not use Pistols, Assault Troopers and Assault Captains will occasionally drop ammo for the Pistol when they are killed. They are known to be 9mm PAK.









Shotgun
The Shotgun is a strong weapon in every Duke Nukem game from Duke 3D onwards. It is mostly accessible early on in every game and is very popular among players. It is used both by Duke and the Pig Cops, among other enemies. The shotguns are always a grayish black, and usually have Pistol grips.
A sleek 12 gauge single barreled pump-action shotgun with a pistol grip. It resembles a Winchester 1300 Defender shotgun with forend pistol grip, heat shield and an extended magazine tube.
It is a good, close range weapon, very damaging, but inaccurate at large distances. It has an average rate of fire. Duke pumps it after each shot.
When the Shotgun is fired, seven hitscan trails are projected from the player, with each trail inflicting 10 damage. The trails are spread out a little, meaning distant enemies will likely only be hit by a couple of the trails, and so take less damage than they would at close range.













Chaingun Cannon ("Ripper")
The Chaingun Cannon (also known as the Ripper Chaingun, or simply Ripper/Chaingun) is a weapon that is usually found early on in some of the Duke Nukem games.
The Chaingun Cannon is a Nordenfelt-type machine gun, hence the multiple barrels. It can tear up most enemies at close quarters (hence the name Ripper), however it is very inaccurate at long distances.
The Chaingun Cannon is the weapon Enforcers wield (a different design known as the Prosthetic Hand-Held Minigun). They'll drop either a Chaingun Cannon or ammo for it when they die for the player to pick up.













RPG
The RPG (short for Rocket Propelled Grenade) is one of the most powerful weapons in the Duke Nukem series.
A chrome, cylindrical belt-fed weapon that is held like a Sten gun and is capable of firing massively-damaging rockets.
The RPG and ammo for it are rare, which is understandable for such a powerful weapon. Nevertheless, it can often be obtained early in the game as a secret item.
No enemies will drop ammo for this weapon.








Pipe Bomb
The Pipe Bomb is an improvised explosive device (IED) found throughout most of the games in the franchise. It is an explosive in a metal casing and is detonated with a handheld detonator. It is very effictive for taking out large groups of enemies in close quarters.
The Pipebombs are rather small pipe-formed bombs that a player can throw out and detonate at will. There's actually no limit on how many Pipebombs the player can throw out before detonating.
Both the Battlelord and Mini Battlelord wields a form of a Chaingun Cannon with a attached mortar launcher; although they look nothing like the Pipebombs and act as proximity mines instead of triggerable mines, they share the same "impact" sound as the Pipebomb whenever they hit the ground.














Shrinker
The Shrinker (also known as the Shrink Ray) is a weapon capable of shrinking an enemy, making it possible to stomp it. It doesn't discriminate by hit points (although bosses are immune) and often is a weapon to use against strong foes.
The Shrinker is first picked up in the Lunar Apocalypse level Spaceport.
On the Sega Saturn port the Shrinker is first found in The Abyss.
The Atomic Edition expansion later included a counter-part of the Shrinker, the Microwave Expander.
The primary and only function of the Shrinker is to shrink enemies. Even though it inflicts no damage whatsoever, it's arguably one of the most devastating weapon in the entire franchise. The player should come closer and stomp the shrunk enemy, otherwise the enemy will turn back to normal after 11 seconds.
The Shrinker has a surprisingly fast firing rate and can emit a large quantity of projectiles in a short period of time.
The Protector Drone is capable of using a Shrinker as the ammo used by the Shrinker seems to be actually a mineral (crystal). It doesn't drop a Shrinker or ammo for it, however, and it is immune to the Shrinker.
A Battlelord Sentry usually needs more accuracy to be hit.











Freezethrower
The Freezethrower is first found in the Lunar Apocalypse map Incubator.
The Freezethrower is mainly used to make enemies turn into a block of ice unable to do any form of action until the ice melts or, if they're unlucky enough, shatter into a million of pieces by a single bullet or kick. It has a fast rate of fire but is not very efficient at longer distances.
The Flying Frosty from the Duke: Nuclear Winter expansion fires ice crystal very much in the same vein as the Freezethrower, although they seem to inflict more damage than the players.

Devastator
The Devastator is a Gyrojet-type weapon found throughout most games in the franchise.
The Devastator is a rapid fire rocket launcher weapon fed from overhead pan magazines which spits out small incendiary rockets at an impressive rate of fire like a machine gun. Note it has recoiling blast shields around its muzzle to deflect the flash from the user. The accuracy becomes less effective at longer ranges. The Devastator is immediately recognized by its dual-wielded appearance, unlike any other weapon in the game.
One should be aware when using the Devastator; it fires 2 rockets simultaneously and therefore each time the player fires the weapon the ammo count drops by 2 each time the weapon is fired. You can fire a max of 5 times before running out of ammo, as picking up a new Devastator will give you 15 ammo. Obviously it takes far less rockets to kill weaker opponents like Assault Troopers or Sharks - just 1 shot if accurate enough.
The weapon is the most powerful when it comes to an enemy with more hit weapons. Unfortunately it is not very effective in multiplayer combat.
"Straight out of the pentagons secret labs comes this double barreled brute of a weapon which lets loose swarms of minature stinger missiles in the direction of your enemies. Ammo packs contain 50 rockets. You can carry up to 99 rockets" - Manual description









Microwave Expander
The Microwave Expander (also known as just Expander) is a new weapon presented in the Plutonium PAK expansion pack. It is an extension of the Shrinker weapon and uses a secondary slot in the keyboard.
The player can equip the Expander for the first time in the first level of Lunar Apocalypse episode, Space Port in the Atomic Edition as it's an extension of the Shrinker; however the player doesn't get the chance to use it till The Birth. Ammunition for the Expander will finally make its debut in It's Impossible.
The Expander may not be picked by itself; instead, it becomes available to use when the player has the Shrinker and picked up some Expander ammo. When the Expander is activated, it looks similar to the Shrinker, but the crystal within is red rather than green, and an antenna reflector is mounted on the weapon.
The attack function of the Expander is the opposite of the Shrinker. Instead of shooting green projectiles, it is a hitscan weapon that emits small glowing sparks that instantly hit the enemies. Once an enemy is at the brink of death, they'll grow and expand almost double their size, and eventually explode into a shower of blood and gore, damaging any unlucky enemy or player standing near it.
While the Shrinker is better used against strong foes, the Expander may be exponentially more devastating against weaker ones.
The Expander is the most powerful hitscan weapon of the game. It has the highest damage and completely accurate auto-aim (being the highest menace in a Dukematch combat). Its side-effect increases its threat even more. Despite that, the weapon has a very limited maximum amount of ammo.














Laser Tripbomb
The Laser Tripbomb is first found as a usable weapon in the Spaceport level in the episode Lunar Apocalypse. Before then, it is found already set, as traps for the player, first in the Death Row level in the episode L.A. Meltdown and in some subsequent levels.
The Laser Tripbomb is a weapon mainly used for setting traps. Once a player places it on a wall it'll activate after two seconds emitting a red laser beam coming from the Tripbomb, going across the room and ending once it hits a solid wall.
Any player or monster breaking the red laser beam will instantly destroy the Tripbomb which result in a explosion together with an enormous splash damage.














Incinerator
The Incinerator is a weapon introduced in Duke Nukem 3D: 20th Anniversary World Tour.
The Incinerator is to all intents and purposes a flamethrower. It is very effective at killing enemies at close range. When an enemy is struck by the weapon; if they catch fire they will be set alight and wander aimlessly while the flames deal damage to them. If the enemy loses enough health they will be burned to ash.
Some enemies can be killed with one shot (I.E Assault Trooper or Enforcer) but tougher ones (I.E Protector Drone or Assault Commander)may require two or three shots. This weapon is less effective against machine based opponents such as the Pig Cop Tank as they don't catch fire. It is also a poor choice against mini bosses such as the Battlelord Sentry as they don't catch fire either.
Another way to use this weapon is to fire at the ground which will leave an incendiary pool of liquid; if the enemy walks in this they will also be set alight. The player should be cautious as this will also harm them if they walk in it.
The incinerator is also the first weapon introduced to the game that will not work underwater.

Jetpack
The Jetpack is an inventory item in Duke Nukem 3D and its ports.
The Jetpack is a large silver device that is worn on the back. It propels the wearer into the air.
Whenever the Jetpack is in operation, it depletes its fuel at a constant rate, regardless of the movement the wearer is performing.













Holoduke
The Holoduke is an inventory item in Duke Nukem 3D and its ports
The Holoduke is a device that projects a fully realistic image of its user in the position it is used in (it drops to ground level if used in the air). It rotates depending on its user's direction but does not copy any other action its user does.
If used underwater, the Holoduke will appear as a swimming Duke, even if the player is above water. The opposite is also true.














Portable Medkit
The Portable Medkit is an inventory item in Duke Nukem 3D and its ports.
The Portable Medkit provides instant relief for anyone unable or unwilling to go look for a Small or Large Medkit.
A new Portable Medkit contains a total of 100 health points. Upon using it, health points are immediately transferred from the Portable Medkit to the player until either they are at full (100) health or the Portable Medkit has no more health points to give (upon which it is automatically discarded).
Picking up a new Portable Medkit when holding a partially used one will cause you to discard your currently held one and pick up the new one. The health points in the partially used Portable Medkit will therefore be lost, so it is wise to collect them carefully.














Scuba Gear
The Scuba Gear is an inventory item in Duke Nukem 3D and its ports.
The Scuba Gear prevents the player from drowning, thus allowing them to explore underwater areas at relative leisure.
A new Scuba Gear has a full tank of air, which is used up relatively slowly while underwater. Once the Scuba Gear runs out of air, Duke then holds his breath and then starts to drown as if he had just entered the water.
Picking up a new Scuba Gear when holding a partially used one will cause you to discard your currently held one and pick up the new one. The air in the partially used Scuba Gear will therefore be lost, so it is wise to collect them carefully.













Protective Boots
The Protective Boots are an inventory item in Duke Nukem 3D and its ports.
The Protective Boots prevents the player from taking any damage while standing on a damaging floor surface, such as slime, lava and purple radioactive waste.

The effectiveness of the Protective Boots depends on the surface the player is walking on:
Green slime - Roughly 50 seconds
Lava - Roughly 25 seconds
Purple radioactive waste - Nearly 8 seconds

Picking up new Protective Boots when holding a partially used pair will cause you to discard your currently held pair and pick up the new ones. The protection from the partially used Protective Boots will therefore be lost, so it is wise to collect them carefully.













Access Card
The Access Card (or Key Card) is an inventory item in Duke Nukem 3D and its ports.
The Access Card is used on an Access Card Panel in order to unlock it. This is turn will cause something to happen, such as a door being unlocked or part of the environment moving.

There are three colours the Access Card comes in:
Blue
Yellow
Red

Only one Access Card of a given colour may be carried at once. This is not noticeable in the main game, as there is no situation where the player is able to pick up an Access Card whilst already holding one of the same colour. However, some user maps may be designed in such a way that this fact is revealed.
When an Access Card is used on an Access Card Panel, all linked Access Card Panels are unlocked at the same time, meaning the Access Card itself only needs to be used once. As such, the Access Card is disposed of once it is used.














Night Vision Goggles
The Night Vision Goggles are an inventory item in Duke Nukem 3D and its ports.
The Night Vision Goggles amplify all ambient light levels, allowing the exploration of dark areas. As suggested by their green lenses, the resulting brightened image is tinted green.
Any enemy that is looked at through the Goggles is shaded a very bright green so that they stand out.
Picking up new Night Vision Goggles when holding a partially used pair will cause you to discard your currently held pair and pick up the new pair. The batteries in the partially used Goggles will therefore be lost, so it is wise to collect them carefully.














Steroids ("VItamin X")
The Steroids (Vitamin X in the N64 port) are an inventory item in Duke Nukem 3D and its ports.
The Steroids will double a player's speed, and multiply the damage dealt by the Mighty Boot and Quick Kick by 4. They will also instantly restore a shrunken player's original size, and render the player immune to shrinking while under the effect of the Steroids.
The effect of Steroids cannot be deactivated once activated. They will drain completely
If a player picks up a new bottle of Steroids while they are draining their currently held bottle, the effect of the Steroids being used will immediately disappear and the new Steroids will be added to the inventory (as unused).














Atomic Health
The Atomic Health gives the player 50 health when picked up. Unlike other healing items, the Atomic Health will heal the player up to 200 health points; 100 points greater than the player’s default health. This makes picking up the Atomic Health always a good idea, because having up to 100 extra health points is always useful.
Because the Atomic Health is so useful, its usually hidden either in secret or hard to get to areas.

Assault Trooper
The Assault Trooper (also known as the Predator Trooper or Lizard Trooper) is the most common enemy in Duke Nukem 3D, and appears in almost every level. It is first encountered in the first level of L.A. Meltdown, Hollywood Holocaust.
The Assault Trooper is the lowest-ranked grunt in the alien invasion, armed only with a laser blaster. It is also one of the most common (and thus most reliable) grunts of the entire alien attack force assaulting Earth. Its job is to stay on the front lines and do all the dirty work for its Lord. It is the first alien the player encounters in the game.
The Assault Trooper should not be underestimated. Each Assault Trooper owns a jetpack, and uses it to get closer to the player or to gain the high ground. This makes it rather difficult for the player to flee the battlefield, or to pick them off from above. Also, when attacking in groups the Assault Trooper will try to flank the player, making it more difficult to withdraw to a safer area. Finally, the Assault Trooper is the only enemy in the game that can "play dead", allowing it to make a surprise attack on the player later.











Assault Captain
The Assault Captain (also known as the Lizard Captain) is a stronger version of the Assault Trooper. It is first encountered in the first level of L.A. Meltdown, Hollywood Holocaust.
The Assault Captain's job is to lead the Assault Troopers in battle. Ruthless and cunning, it directs minor battles with ease. It is the same species as the Assault Trooper; its only distinguishing feature is its red armor (which apparently signifies leadership, or at least a higher level of authority than green/blue).
Twice as tough as its underlings, and carrying a small wrist-mounted teleporting device in addition to its laser blaster, the Assault Captain is the master of sneak attacks. Often teleporting itself before the player has seen it, it can come as a nasty shock when it strikes.









Pig Cop
The Pig Cop (affectionately referred to as Piggy, Piggycop or just Pig) is an enemy in Duke Nukem 3D, and is not only the enemy with the most permutations in the game, but is also one of the most popular ones. It is first encountered in the first level of L.A. Meltdown, Hollywood Holocaust, and does not appear at all in the episode Lunar Apocalypse.
Pig Cops are muscular humanoid boars, mutated from LAPD officers shortly before the beginning of Duke Nukem 3D. It appears only in Earth-based levels (and thus not at all in Lunar Apocalypse, except as two corpses found in Dark Side). Fierce and fearsome, the Pig Cop is one of the most well-known enemies in the game. They are often compared to the Enforcers, sharing the same strength and aggressiveness in combat.
They are cunning in battle, often dropping to the ground to make themselves smaller targets while they fire their shotguns at their victims. They patrol mostly on foot, but also in tanks or aircraft. In groups, the Pig Cop is a fierce opponent which should not be underestimated due to their high pain tolerance and devastating Shotgun attack.
Pig Cops are described in the game's instructions page, that (cited) they are 'extremely intolerant towards humans and exhibit blind rage when they detect human scent'. This could lead for the fact, that Pig Cops are misanthropes, human-haters.
The Pig Cop retains much of the knowledge and intelligence of the human that mutated into it, but thanks to the alien influence they have been turned against humanity. They are described as 'alien operatives' who 'suppress residual human opposition'. However, they do not attack females.
Apart from the voice players can hear at the end of E1L2, they seem incapable of speech, instead producing a variety of lower-pitched squeals and grunts.









Recon Patrol Vehicle
The Recon Patrol Vehicle (commonly abbreviated to RPV or called the Recon Car) is a relatively rare enemy in Duke Nukem 3D. It, like all Pig Cop-related enemies, does not appear in any level of the second episode Lunar Apocalypse. It is first encountered in the second level of L.A. Meltdown, Red Light District.
The Recon Patrol Vehicle is a quick and agile reconnaissance flying vehicle, formerly owned by the LAPD but now in the hands of the Pig Cops. Armed with twin laser blasters and minimal armor, the RPV cannot take much damage, but its maneuverability easily makes up for it. It can effortlessly dodge projectile weapons (such as rockets), making it very difficult to hit with anything powerful enough to do it serious damage.
Its main use is for patrolling and scouting outdoor areas. It has a set flight plan, and will protect the area in which it flies by firing upon intruders with its twin laser blasters. It is often to be found flying around city streets a few metres above them, although it may be assigned to other locations as well. It flies high in the air to allow the sturdy underside of the vehicle to take shots from below, thereby protecting the exposed pilot.
The Pig Cop is not harmed when the RPV is destroyed. Instead, he survives and starts attacking. This is due to the RPV being equipped with a jettison device which automatically ejects the pilot (a Pig Cop) when it is destroyed and spiraling to the ground. This makes it two enemies in one, and all the more dangerous for it.









Octabrain
The Octabrain is an enemy in Duke Nukem 3D. It is first encountered in the second level of L.A. Meltdown, Red Light District.
The Octabrain is a large beige floating brain with tentacles, mean eyes and big teeth. It can expertly use incredible psychic powers, both as a means of movement and as a weapon. It also seems to be the most intelligent enemy in the game, a theory heavily inspired by the size of its brain.
It seems to follow its own agenda, rather than that of the invading aliens. While the other aliens are attacking places and using excessive force to invade Earth, the Octabrain lurks in the shadows. It can often be found guarding nests of Protozoid Slimer Eggs (with babes trapped in slime/vines sometimes nearby), an observation that has grown into the theory that the Octabrain and the Protozoid Slimer are related. It is at home both underwater and on land, and is the most notable underwater-based enemy.











Turret
The Turret is an enemy in Duke Nukem 3D. It is first encountered in the first level of L.A. Meltdown, Hollywood Holocaust. It is a common enemy in the game.
The Turret is the security measure of choice. It is a fixed structure that fires laser blasts at any enemy unfortunate enough to come into range (and it has a large range). Often used to protect military installations, important areas, or just to make Duke's life annoying, the Turret is often mounted in inconspicuous places that make it hard to spot, most often on ceilings and other overhead architecture. They inflict significant damage and are deadly accurate.
The Turret used to be a force for good (or rather, for the military), but the aliens have reprogrammed them to see humans as enemies instead of them.

Assault Enforcer
The Enforcer is an enemy in Duke Nukem 3D. It is first encountered in the first level of Lunar Apocalypse, Spaceport, and does not appear at all in the episode L.A. Meltdown.
Space's alternative to the Pig Cop, the Enforcer first appears in the space-based episode Lunar Apocalypse (and is absent from L.A. Meltdown; compare with the Pig Cop, which appears in the first episode but not the second). This dinosaur-like creature is fast on its feet, and is able to leap high into the air, meaning it can give the player quite the run around.
It is equipped with a deadly chaingun, which is either worn over its right arm or, more likely, replaces it. Its spit is also very harmful to humans, making it a dangerous opponent. However, it will stop attacking on occasion to defecate, a distraction which the player may use to their advantage.









Assault Commander
The Assault Commander (sometimes called the Fat Commander) is an enemy in Duke Nukem 3D. It is first encountered in the third level of Lunar Apocalypse, Warp Factor, and does not appear at all in the episode L.A. Meltdown.
The Assault Commander is the most dangerous alien in the "Assault" group. Stronger and deadlier than the other "Assault" troops, the Assault Commander sits on a flotation platform commanding its forces via a radio headset. When facing an enemy itself, it will often taunt them with evil throaty laughter and phrases such as, "Die, human!" or "Suck it down!" (Duke's quote when gibbing an enemy). It is one of the most dangerous enemies in the game.
It has the unusual ability to create and/or store explosive rockets within its body, and happily fires them at its enemies in rapid succession from what appears to be its rectum. It can also use its spiked flotation platform as a melee weapon by spinning rapidly and ramming into its foes, slashing them.










Protozoid Slimer
The Protozoid Slimer (or just called the Slimer) is an enemy in Duke Nukem 3D, and is often seen along with Protozoid Slimer Eggs from which they hatch. The two are first encountered in the second level of Lunar Apocalypse, Incubator.
The Protozoid Slimer is little more than a green blob with a number of small tendrils around the sides. On the bottom of the Protozoid Slimer is a large mouth lined with jagged teeth. It is smaller than nearly every other enemy in the game (except for the Turret). Protozoid Slimers' exact function in alien hierarchy is unknown, though it seems they produce the green biomass of alien hives, and could cover with it both structures and captured women.
It is a nasty little creature. It may not seem very menacing from a distance, and indeed it isn't, but when it has latched itself to your head and is biting your face off, you'll think differently. These soft puddles of green goo are very stretchy, and often swarm in great numbers and attack their enemy without warning by dropping onto them from the ceiling.
According to the manual, protozoid slimers attack by sucking out Duke's brain through his nose.
Slimers will also eat other alien troops, especially if they are coming after you and the alien is between you and the slimer. They will even eat protector drones, one of the most powerful aliens, and consume them in a single bite. However, they cannot eat the level bosses.














Sentry Drone
The Sentry Drone is an enemy in Duke Nukem 3D. It is first encountered in the first level of Lunar Apocalypse, Space Port.
The Sentry Drone is a flying robotic suicide bomber. When you hear its antigrav engines revving up, you know you're in for a world of hurt.
It is a highly intelligent machine, capable of evading incoming fire to ensure that it reaches its target to deliver its payload. Other than its explosive payload, it has no weaponry, and makes up for this with a tough armored shell. It is fast-moving, and designed to deliver pain where it's not welcome. It appears to be a human invention like the turret, but reprogrammed by the aliens to see humans as enemies.









Battlelord Sentry or "Mini Battlelord"
The Battlelord Sentry (also called the Mini Battlelord, Battlelord Junior or Battlelord Clone) is a smaller and weaker version of the Battlelord. It appears several times in the episodes Lunar Apocalypse, Shrapnel City and The Birth, but not at all in the first episode L.A. Meltdown.
It is the strongest non-Boss enemy in Duke Nukem 3D. Also, a Battlelord Sentry appears on the end of Duke Nukem's Penthouse Paradise serving as a "boss" for this add-on, but doesn't need to be killed in order to finish the add-on, just passed-by.
In the latest release Duke Nukem 3D: 20th Anniversary World Tour the Battlelord Sentry can be encountered in L.A. Meltdown since Faces of Death can now be played as a regular secret level and is considered part of the first episode. The Battlelord Sentry also makes further appearances in the new episode Alien World Order.
The Battlelord Sentry is one of the most powerful, and dangerous non-boss enemies in Duke Nukem 3D. It has masses of health and an arsenal as large as its counterpart. However, it is smaller than the Battlelord, and so is unable to step on foes with its feet when they venture too close, but getting up close to it will cause it to fire its chaingun to cause significant damage as Duke is in range of the Battlelord Sentry.
It has omnipotent accuracy with its chaingun, even over some of the most farthest distances, and the explosive mortars it occasionally fires from its mortar launcher are very dangerous as the mortars themselves can become "land mines" and explode when they are touched. The mortars are very powerful when they connect and will most likely kill at around 45-55 health.














Shark
The Shark is a enemy in Duke Nukem 3D. It is first encountered in the first level of Shrapnel City, Raw Meat.
The Shark is a fearsome predator that strikes terror into the hearts of men. It attacks without warning, inflicts massive damage on its prey and disappears just as swiftly.
At least, that's how they should be. Unfortunately, these creatures are overshadowed by the alien invasion, which relegates the Shark to the position of "weakest enemy".
Much like the cocooned babes the Sharks have red eyes, and strangely, they will never attack the aliens besides they're supposed to be just wild and hostile animals. This make possible that the Sharks have been infected by the protozoid and are being somewhat controlled by the aliens to cover underwater areas.
If the former is false and the Sharks really are on their free will, this is the only enemy in the original game that is not in league with the alien invasion, and will attack Duke Nukem just because its nature.

Pig Cop Tank
The Pig Cop Tank (also known as the Riot Tank) is an enemy in Duke Nukem 3D. It was introduced in the Atomic Edition of the game, and is only in the episodes The Birth and Alien World Order.
It is first encountered in the second level of The Birth, Duke-Burger. It is considered to be the most dangerous enemy after the enemy bosses and the Mini Battlelord.
The Pig Cop Tank is the natural counterpart to the Recon Patrol Vehicle. While the RPV is fast and maneuverable, the Pig Cop Tank is slow and clumsy. It is a land-based vehicle, and has a lot more fire-power than the RPV to make up for its comparatively poor agility. It is heavily armored, so it can take a lot of damage. When it is destroyed, there is a 50% chance that its driver will escape unharmed. As the vehicle's name suggests, its driver is a Pig Cop, whose shoulders and head can be seen.
A notable feature of the Pig Cop Tank, aside from its devastating weaponry and armoring, is the button on its back. It is a self-destruct button, and allows a sure-fire and simple way of destroying it (provided one can quickly get close enough to press it).









Protector Drone
The Protector Drone (also known as the Alien Beast, Newbeast or the Alien Drone) is an enemy in Duke Nukem 3D. It first appears in the Atomic Edition of Duke Nukem 3D, in the fourth episode, The Birth. It is first encountered in the first level of The Birth, It's Impossible. They also appear once in the Alien World Order episode level, Mirage Barrage.
This monster is a human-alien hybrid, and since a horde of Protector Drones were seen in the video footage at the start of the fourth episode surrounding a pregnant woman about to give birth (presumably to the Alien Queen herself), their creation by the hands of aliens preceeds that of the Queen, which was created to breed them en masse. The Protector Drones protect the Queen and her domain, and also serve as a sort of bio-weapon, as they hunt Duke Nukem since the very beginning of episode four. In episode five, Alien World Order, some of these hybrids still exist and are deployed against Duke in Egypt.
The creation of Protector Drones appears to be the main concern of alien invasion, beside the conquest. After the Protector Drones and the Alien Queen were created, the aliens stopped to kidnap women, as seen in episodes four and five.
The Protector Drone is a very dangerous enemy. It is very quick-moving, has powerful slashes, can take a beating, and it can disable its foe with a single shot of its Shrink Blast. This lean beast is not for underestimating but, preferably, for termination with extreme prejudice.








Firefly Trooper
The Firefly Trooper is an enemy introduced in the Alien World Order episode of Duke Nukem 3D: 20th Anniversary World Tour. They sometimes drop Incinerator ammo when killed.
The Firefly has the least appearances of any regular enemy in Duke Nukem 3D, only appearing in High Times, Mirage Barrage, and Golden Carnage.
The Firefly doesn't take much punishment but it is still a deadly opponent at close quarters. It is armed with an incinerator that can kill the player in seconds. The Firefly also has the ability to make itself smaller to make it easier to sneak up on the player and like the Assault Trooper it also has a jet pack; however it only uses this when it makes itself smaller and harder to hit.

Battlelord
The Battlelord acts as the first boss the player encounter in Duke Nukem 3D; greeting the player in L.A. Meltdown and at the The Abyss level. Also he is the final Boss of the Duke Nukem 3D Shareware episode.
Weaker and smaller versions will frequently appear in later episodes, known under the tile of Battlelord Sentry.
In episode five, Alien World Order (released in 2016), there are two more Battlelords to slay. One is encountered in the secret level, Prima Arena, while the second commands the alien base in France, on the level Tour De Nukem.
The Battlelord wields a chaingun (prosthetic minigun design) with a built-in mortar launcher. Its chaingun is also significantly more powerful than the Enforcer 's. The hulking Battlelord commands the first wave of the alien invasion force on Earth. Its deafening roar splits the air as its deafening chaingun and mortar rounds tear resistance asunder. It has no known weaknesses; only relentless firepower and staying on the move will win the day.















Overlord
Overlord is the boss of the episode Lunar Apocalypse in Duke Nukem 3D, and appears in the level Overlord. He is the second boss in the game.
The fifth episode, Alien World Order, released in 2016, featured the mini-boss versions of the enemy called Overlord Sentry, who appear throughout the game. The level Red Ruckus featured the second Overlord boss, the exact copy of original one, who is fought in a Russian military base.
The Overlord wields two built-in rocket launchers, every rocket is as powerful as the RPG.












Cycloid Emperor
The Cycloid Emperor is the final boss in the original Duke Nukem 3D and appears in the third episode, Shrapnel City, found during the Stadium level. It should be noted as of v1.4 (Atomic Edition), he becomes a third boss and he is no longer the final boss as a fourth episode (The Birth) was added which also introduces the Alien Queen, as well as the release of the Alien World Order, fifth episode, in 2016.
The Alien World Order (episode five) also featured multiple encounters with Cycloid Sentry, the mini-versions of the boss. Also, another Cycloid Emperor boss appears on the level Bloody Hell (though he may not be "Emperor" storywise, just as big and powerful). The same level marks the first appearance of Cycloid Sentry.
Other Cycloid Emperors are the bosses of the authorized expansion packs, Duke it out in D.C., Duke!ZONE II, and Duke Caribbean: Life's A Beach.
Cycloid Emperor is the leader of the alien race Duke battles. Encountered in Stadium, it attacks the player with a rapid-spread version of the Octabrain's mental blast at close range. It will also fire a large barrage of missiles at a distance, with the exact amount of damage inflicted as Duke's RPG.
There are also other Cycloids, the bosses of Duke it out in D.C., Duke!ZONE II, and Duke Caribbean: Life's A Beach. The Cycloid in Duke it out in D.C. is the same, with only difference that the battle arena is smaller, making the fight harder. The Cycloid in Duke Caribbean: Life's A Beach has a different model, as he wears Caribbean attire, and also attacks Duke from behind.













Alien Queen
Alien Queen is the boss of The Birth in Duke Nukem 3D as well as the boss of the fourth episode in the Atomic Edition. She is the leader and mother of all Protector Drones. Since the release Duke Nukem 3D: 20th Anniversary World Tour and its fifth episode, Alien World Order, she is a no longer the final boss, as Cycloid Incinerator takes this title.
Although not directly stated, it is implied that the Alien Queen is the alien-human hybrid that was born at the beginning of The Birth. Her exact status and role in the overall alien hierarchy is not entirely known, but obviously, she is one of the leaders of the alien invaders and is the main source of Protector Drones.
The Alien Queen resides in an underwater chamber heavily guarded by Protector Drones and Octabrains. To reach the Alien Queen, the player must first cross a highly toxic canal before reaching a pool that leads to the Queen's underwater chamber. Out of all the bosses in the game, she and CyberKeef have the most health.















Cycloid Incinerator
The Cycloid Incinerator is the final boss of Alien World Order and Duke Nukem 3D. He appears in the level Hollywood Inferno.
He is very similar to his original counterpart, the Cycloid Emperor, but is red in color and is armed with a flamethrower instead of rocket launcher. His appearance is more less a palette swap as there are no other visual differences other than a few edits.
No story is given about this particular boss. The logical conclusion is that Cycloid Incinerator is the new Cycloid Emperor after the death of the first one at Stadium, who launched world-scale invasion alongside several other Cycloids, who are just underlings.