Double Dragon is a series of side-scrolling Beat 'em Up's that helped popularize the genre back in the late 1980s and early 1990s.The original 1987 arcade game, developed by the now-defunct Technos Japan Corp. and distributed by Taito, featured a rather simple and standard premise: twin martial artists Billy and Jimmy Lee must save their lady-friend Marian from the clutches of the Black Warriors, a ruthless gang that controls the city.While not the first of its kind, as Double Dragon was originally intended to be a sequel to their previous game Renegade, the game improved upon its predecessor's formula by allowing up to two-players to play simultaneously and adding the ability to pick and use weapons against the enemies (both features would become standard in subsequent games in the genre). The 2-Players Mode also provided a twist in the end: if both players manage to make all the way to the end, then the two would be forced to fight each other to the death, with the survivor getting to claim Marian for himself.Double Dragon was followed by two arcade sequels and numerous home versions for various platforms. The three NES versions (along with the first two Game Boy games and the SNES-exclusive installment) were actually developed by Technos themselves, while most of the other versions were licensed out and developed by other companies. The series died out after Technos went out of business in 1996 (long after the beat-'em-up boom ended), despite attempts to adapt it into a Fighting Game format. The series was revived when Million Corp., a company founded by former Technos staff members, bought the IP. While the series is nowhere near as prevalent as it was back in the day, it still gets an occasional new game once in a while.In addition to the games, there was also an Animated Series and a live-action movie, as well as a comic where their dad was Stan Lee. Yes, that one.Games include:
An unrelated Double Dragon II was released for the Game Boy in 1991. It is actually a localization of a Kunio Kun game.
Double Dragon 3: The Rosetta Stone (1990, arcade)
Double Dragon III: The Sacred Stones (1991, NES) - Released for the Japanese Famicom as Double Dragon III: The Rosetta Stone. Almost a completely different game from the arcade version (then again, the same could be said about the first two NES games).
Ported to the Game Boy and Sega Genesis as Double Dragon 3: The Arcade Game.
Acrofatic - Chin Seimei (and his Palette Swap brothers who appear only in the third arcade game), as well as McGuire from the SNES game.
Action Girl - Marian and Rebecca in the Neo-Geo fighting game.
Adaptation Dye-Job - Billy (Player 1) had blond hair in the original arcade trilogy, while Jimmy (Player 2) had brown hair. When the games were adapted for the NES, the hair colors were switched, giving Billy brown hair (although often depicted as red hair) and Jimmy blond hair. The later console installments for the SNES, PCE and GBA stick to the NES style.
The opening sequence of the first NES game (in which the Black Warriors kidnap Marian) depicts Jimmy Lee with blue hair instead of his usual blond, although this could be attributed due to the number of different characters (Marian, Jimmy, Chin, Williams and Rowper) appearing in the scene, using up the limited color display of the NES (in the actual game, enemies always fight alone or in pairs and always as clones of the same character), causing Jimmy and Chin to use an unusual palette in the opening.
In the NES sequels, Jimmy's in-game sprite depicts him with red hair like Billy's, despite having blond hair in the cut-scenes and character select portrait.
The ending photograph of the second arcade game the Lee twins are depicted with the switched hair colors they had in the NES games.
Adaptation Expansion - The GBA game is a remake of the original arcade game that not only features almost all the stages, moves, and enemy characters from the arcade version, but also feature quite a few stages, enemies, and moves clearly inspired by later ports and installments.
After the End - "In the year 199X, violence ruled the streets of New York after the nuclear war."
Alternate Continuity - The NES version of the trilogy have many plot differences from their original arcade counterparts (specifically when it comes to the identity of the Black Warriors' leader in the first game and Marian's survival in the second). All the later games are stand-alone.
All There in the Manual - The names of the enemy characters are never mentioned in-game in most of the titles (except for the NES version, where all the bad guys except Willy are playable in the Versus Mode, although Williams' name is shortened to "Will" and Chin Taimei is only referred by his surname). This was before Final Fight introduced the idea of giving the enemy characters life gauges with their names.
Artifact Title - The NES version of the first game ran the risk of having one due to the developers' inability to include a 2-Player co-op mode at the time. Since having a game titled Double Dragon with just half of the titular duo wouldn't had made sense, Technos decided to subvert this by taking a cue from the arcade version's twist ending, in which both brothers fought over Marian, by having Jimmy (Player 2 in the arcade version) as the final boss.
The Game Boy version plays this straight by lacking a co-op mode as well and ending the game with the final boss fight with Willy.
The arcade version of Double Dragon 3 introduces a previously-unseen third Lee brother named Sonny exclusive to that game. Apparently "Triple Dragon" didn't have quite the same ring to it.
Captain Ersatz - The bosses in the arcade version of Double Dragon II. Particularly, Burnov (Mission 1 boss) resembles the Kinnikuman wrestler Neptuneman, while Abore (the Mission 2 boss) is a cross between The Terminator and AndréThe Giant.
Catch and Return - In some games it's possible to catch a knife, leading to this trope.
Charged Attack - In the SNES game the Lee Brothers can charge up a special meter that alters their attacks, starting with the stunning backhand and knock out jumping kick, then with the moving Cyclone Kick, and finishing with the Super Mode when fully charged.
Clean Dub Name - In the second NES game, the enemy gang was changed from the Black Warriors to the Shadow Warriors in the English version, presumably to avoid the Unfortunate Implications of the original name. The "Shadow Warriors" name would be used in the later SNES and GBA games, but the iPhone version went back to using the "Black Warriors".
Color-Coded Multiplayer - Billy is blue and Jimmy is red (except in the second arcade game, where they wore black and white). Gets a bit silly in the third arcade game with the introduction of a yellow-clad Lee brother (Sonny) as the main Player 3 character, along with other palette-swapped siblings (essentially an excuse to allow all three players to use the same character).
Combination Attack - The Back-to-Back Hurricane Kick and the Triangle Jump Kick in both, the arcade and NES versions of Double Dragon III.
Squishy Wizard - The Lee Brothers (Billy, Jimmy and Sonny)note Their basic attacks are weaker than the other characters and they have about as much health as the Oyama Brothers, but they make up for it by their exclusive ability to pick up and use nunchakus and swords.
Jimmy Lee in the first NES game, who not only serves as the new final boss, but essentially replaces Jeff (the head-swapped Lee brother boss from the arcade version) as the boss who uses all of the player's moves.
Abore in the second NES game has the same moves as his namesake from the arcade version, but his appearance resembles that of Oharra's, an Abobo head-swap from the arcade version.
Conservation of Ninjutsu - The twin ninjas from II and Ranzou from III are bosses (the latter becomes a playable character). Ranzou's minions are fodder.
The promotional illustration for Double Dragon II: The Revenge (as seen above) shows Marian alive, despite being killed in the beginning of the game (the happy ending where Marian is brought back to life was not in the arcade version and was only added in the NES version). Even stranger is the fact that the artwork shows Marian embracing the Lee brother in red, when her boyfriend is established to be Billy, the Lee brother in blue (perhaps a result of Billy and Jimmy having switched hair colors in the console version).
The Japanese cover art for the Game Boy version also depicts Billy wearing red instead of his traditional blue. But given that the Game Boy version has black and white graphics, his outfit could be in any color.
A much straightforward example can be seen in the cover art for the first NES game, which shows Billy and Jimmy as literal Bash Brothers, clenching their fists together at the background and teaming up against a pair of punks on the foreground, despite the fact that Jimmy was Billy's nemesis in the NES version. The computer versions released shortly after the NES game used the same cover artwork, but most of them had the 2-player co-op mode, so the use of the same artwork was not as misleading in those versions. The Famicom version had an entirely different cover art as well.
Averted entirely by Double Dragon Neon. Everything that appears on the box art appears in-game.
Counter Attack - The SNES game features an armlock move that allows the player to grab an enemy's arm by blocking his punches and then use the opportunity for multiple punches and kicks or a throw (which only works on some enemies). The Chen brothers can do the same to the player's kicks, while Duke can counter the armlock. In Advance this returns in form of nerfed catch and throw combo.
Critical Existence Failure - Subverted a little, weakened enemies will be more vulnerable to certain attacks (head grab, stomp etc, etc.)and will take more time to recover but otherwise will continue fighting like nothing happened until they're knocked to the ground.
All versions of Double Dragon II use a direction-based attack system where one button attacks to the left and the other to the right, which Technos previously employed with Renegade. This takes awhile to get used to players more accustomed to the original game, since one button does the standard punch combo and the other a back kick depending on the direction the player character is facing.
The NES version of Double Dragon uses A+B as the command for a jump kick—if your character has reached Level 3. Until then, A+B is just a regular jump, not an attack. Forget this bit, and you may jump right into a bad guy's punches.
Damsel in Distress - Marian in the first game, where the objective was to rescue her. She's worse-off in the second game, where she's killed-off instead, although she does return to life in the NES version. The English localization of the third NES game even changed the script in order to make it seem as if Marian was kidnapped once again and ends up being possessed by an evil spirit (even though she never appears in the cut-scenes and the final boss who is supposed to be her was actually a different character in the Famicom version). Averted in the Neo-Geo game based on the movie, where Marian underwent Xenafication.
Deadly Dodging - Somebody thrown a knife at you? Just step aside and let it hit the mook behind you.
Defeat Means Friendship - Chin Seimei is said to be friends with the Double Dragons after his defeat in the third NES game (despite introducing himself by vowing revenge on them for killing his brother in a previous game).
Happens during the final two stages in both, the arcade and NES versions, where the bosses from the first two stages appear as regular grunts. The "degraded" versions are generally just as tough and sometimes have just as much health as the boss versions.
In the arcade version of Double Dragon II, the head-swapped bosses from the previous game appear only as sub-bosses.
Demoted to Dragon - In the first NES game , Machine Gun Willy goes from being the main bad guy to being the last enemy Billy fights before the final battle with his brother Jimmy. He doesn't even appear at all in the second NES game. Likewise, he's just a lackey to the Shadow Boss (who is not Jimmy like in the NES version, but a completely made-up character who vaguely resembles Burnov) in Battletoads & Double Dragon, where they didn't even get his name right (he is called "Roper" instead).
The Mysterious Warrior, an enigmatic figure introduced in the second MES game as the Big Bad, appears in Double Dragon Advance as right-hand man to Machine Gun Willy. He is still Bad Ass, though.
Deus ex Machina - Hiruko's death while trying to enter Cleopatra's tomb with only three Sacred Stones in the third NES game.
The Famicom version of Double Dragon II allows the entire game to be played at any difficulty level, while the NES version restricts the game's length depending on the setting (3 stages on Practice, 8 on Warrior, and 9 on Supreme Master). The NES version also requires the player to input a cheat codes after getting a Game Over in order to continue, whereas the Famicom version had no such requirement. There are other specific differences between the two versions as well: traps are much easier in the Famicom version on the normal setting than in the NES version's equivalent setting (especially the disappearing platforms in Mission 6), but enemies have more health on the Famicom version's hardest setting.
The Famicom version of Double Dragon III starts the player off with more health than in the NES version (10 hit points per character) and there are less enemies to fight. On the other hand, the ending is affected depending on which characters survive the final battle, whereas the NES version always plays the full ending.
Super Double Dragon has no adjustable difficulty settings, in contrast to its Super Famicom counterpart Return of Double Dragon, which had three settings (Easy, Normal, and Hard). However the SNES version is harder than the SFC version set on Hard. The SNES version is missing some of the extra moves in the SFC version, like the ability to switch weapons or catch your boomerangs, while the Hurricane Kick only strikes an enemy once instead of the multiple hits it does in the SFC version. Moreover, dynamites and knives are more lethal in the SNES version, and the enemy placement is different, with more recycled boss characters than in the Super Famicom version. However, the SFC version adds two extra areas to the final stage, making it a bit longer.
Digital Bikini: The cover artwork of the second NES game is the same one used in every other version, except Marian's thigh-revealing skirt was lengthened and her flesh-colored tank top was recolored red.
Direct Continuous Levels: The first two arcade games. Missions 1 throughout 3 are set one after the other, with no cut-aways in-between. It is isn't until reaching the entrance to the enemy's hideout that the game switches to a new level.
Divergent Character Evolution - Billy and Jimmy in the SNES game, where not only their sprites are different (rather than just being palette swaps of each other like in previous games, they started sporting different hair styles), but their basic punches and kicks were different as well.
The original arcade version began development as a Nekketsu Kouha Kunio-kun sequel. The reason why the characters and settings were changed was done to avoid developing a separate version for the foreign market, as was the case with Renegade.
Rage of the Dragons, which was initially planned as a sequel to the Neo-Geo fighting game, but Evoga could not secure the rights to the Double Dragon IP.
Do Not Drop Your Weapon - Willy and his machine gun, the stick wielding version of Chin Taimei, the ninjas in the second and third NES games with their throwing stars and blades, the Japanese swordsmen and Roman gladiators in the third arcade game, the dual-sword wielding Baker from the SNES game, and Kikuchiyo and his cronies in the GBA version.
Doppelgänger - Taking a cue from Zelda II, the Lee brothers must fight their own shadows at the end of the second game.
The twin Abobos in the first game (in both, the arcade and NES version).
The arcade version of Double Dragon II has the twin Burnovs at the end of Mission 3, plus twin versions of all the previous bosses in Mission 4.
The twin ninjas in the second NES game.
The twin Lee Brother clones in both versions of Double Dragon II (but only when two players are present).
The SNES game has the Chen Brothers (Ron-Fu and Ron-Pyo), while the GBA version has Hong and Wong (the Two Tigers).
Dual Tonfas - Rebbecca from the NEO-GEO fighting game wields these.
Dual Wielding - Chin Taimei with the sticks in II, Baker with the swords in Return.
Dumb Muscle - Abobo, especially in the Battletoads & Double Dragon crossover. 'Bimmy and Jammy', the super-muscular clones of the Lee brothers in Neon, also qualify, complete with stereotypical 'dumb' voice.
Dummied Out - The cutscenes in Return of Double Dragon were never fully implemented, but some of the assets that were meant to be used (such as closeups of the Lee brothers and bosses) are still present in the game's data (most of it is compressed and only viewable through save state hacking though).
The Ninja and Migiude enemies from the second NES game were also supposed to appear in the PC-Engine version, but they were cut out from the main game. Their sprites (with full animation frames) are still viewable through a hidden sprite viewer mode, along with Bolo (who is listed in the manual, but it's actually his head-swap Oharra from the arcade version who appears in the game).
Easily Forgiven - In the third NES game, Chin forgets about the Lee brothers killing his brother in the previous game after losing to them.
Easy-Mode Mockery - The NES version of II, which only allows the full set of stages to be play on the hardest difficulty. The PC-Engine version gives different endings instead.
Chin Taimei from the first NES game resembles the Karate Fighter from Mat Mania, a Technos-developed wrestling game, while Abore in the arcade version of II seems to be based on André the Giant from the WWF Superstars arcade game also developed by Technos.
Fastball Special - In the third NES game, both of the Lee brothers and some of the enemy grunts can perform a Triangle Jump Kick where one character jumps unto his partner. The partner proceeds to launch the first character, who then performs a flying jump kick.
Faux Action Girl - Marian, if we are to believe the back-story given in the original game's official soundtrack and some of the console versions, was formerly an assistant instructor in Billy and Jimmy's old dojo. Seeing how she goes down with only one punch to the gut in the opening of the original game without putting much a fight, her qualifications for such a job are debatable. Her Neo-Geo incarnation, on the other hand, does have actual fighting skills.
Fingerless Gloves - The "right arm" thugs who appear only in the second NES game sported them.
Gameplay and Story Segregation - In the second NES game, all the cut-scenes between stages (as well as the opening and ending) only shows Billy, regardless of whether the game is being played alone (with either, Billy or Jimmy) or with both Lee brothers. The only exception is made with the cut-scene when the final boss appears: if both Lee brothers are being used, both of them will appear; but if Billy dies before the final stage and Jimmy survives, then Jimmy will appear in his brother's place.
Sonny, the third Lee brother who appears exclusively in the third arcade game, is absent in the game's opening and ending, while only a single member of each of the other three sibling teams (the Oyama, Chin, and Urquidez brothers) appear in the ending.
Giant Space Flea from Nowhere: At the end of the second arcade game, after defeating Machine Gun Willy in the end of Mission 4, creepy music starts playing and the player's purple Evil Twin rises out of his shadow and attacks him. The game has no other supernatural elements (except for Burnov, the Mission 1 boss who "teleports" after being defeated), nor does the end reference it in any way.
Giant Mook - Abobo and his various head/palette swaps.
Good Bad Translation - The third NES game, while technically not a translation (since it uses an entirely different script from its Famicom counterpart than changes the plot), somehow manages to screw up the spelling of Billy's name as "Bimmy" in the opening of the 2-Players Mode, which has become something of a meme. Strangely, his name is spelled correctly in the single-player version of the opening.
The boss characters in the first arcade game. The Mission 1 boss is a black head-swapped version of Abobo with a mohawk, slightly larger eyes and a beard who could easily pass himself off as Mr. T, while the Mission 2 boss is a head-swapped Lee brother in green clothing.
Starting from the SNES version, Billy and Jimmy began sporting their different hairstyles in their in-game sprites rather than being limited to just promotional artwork and cutscenes like they did in the NES games, with Billy having spiky brown hair and Jimmy having a blond flattop. Only the Neo-Geo fighting game and Neon reverted back to making the Lee brothers into palette swaps.
The NES version of the first game took a cue from Renegade and added a Sit-on Punch to Billy's attack repertoire, allowing him to pin down fallen enemy grunts and punch them while they're down.
The third arcade game allows the player to jump over fallen enemies and stomp them.
Both of the above moves were added to the GBA version.
Neon allows you to punch downed enemies (regardless of whether you knocked them down yourself, they fall down from the sky on fire or are thrown off their malfunctioning hoverbike) for large amounts of damage, although with some enemies it often results in you getting hit by their wakeup attack if you don't do it as quickly as possible.
Launcher Move - Some moves in Advance, most notably the Hyper Uppercut, which can be followed by the Hyper Knee. Performing a weak attack on a stunned enemy inNeon results in an uppercut, which you can follow up with a variety of different moves.
MacGuffin - A different one for each adaptation. The Statue in the comic book, the Sword in the cartoon series, and the Medallion in the movie.
Averted in Double Dragon Advance, where Willy demands the Book of Sou-Setsu-Ken as a ransom for Marian's safety in order to gain greater power. At the end of the game, the book is revealed to be a Magic Feather, as Billy and Jimmy proclaim that they get their strength from their own skills and training.
Madonna-Whore Complex: An invoked meta-example. In the early games, there are two females: Marian and Linda. Marian is the pure and helpless maiden who can't fight; Linda is the evil bitch who fights with a whip.
Martial Arts Headband - Roper in the SNES version. Billy and Jimmy sported some as well in the American cover arts of the earlier games (including the cabinet art for the arcade game), but they never wore any in the actual games.
Martial Arts Uniform - The Oyama Brothers in the arcade version of Double Dragon 3 and many mooks in the rest of the series.
Mission Pack Sequel - The second arcade game is essentially an improved version of the first one, but with a different attack system, new looks and moves for most the returning enemies and new bosses for each stage. The difficulty has also been fine-tuned to prevent players from completing it with just the elbow strike.
Ninja - The nameless ninjas from the NES Double Dragon II, Yagyu Ranzou and his minions from Double Dragon III and Amon from the Neo GeoFighting Game.
Nintendo Hard - The third NES game is ridiculously hard due to having slower basic attacks and no lives system (although, the additional characters obtained by the player in later stages serve a similar purpose). The other two NES games could qualify as well, as both of them have some very unforgiving platforming segments in the later stages. In addition, you have a very limited number of lives without much of an opportunity to collect more, and there are no continues (at least not without inputting a cheat that changes after every third stage).
No Celebrities Were Harmed - The Abobo head-swap in the first arcade game bear a more than mild resemblance to Mr. T, while Abore in the arcade version of II wears a pair of sunglasses with glowing red eyes underneath them that makes him look like a Terminator-clone.
No Ending - The American version of Super Double Dragon gets at least an text only epilogue, but the Japanese release goes straight from the final boss to the credits.note The extra levels are a good tradeoff, though.
The characters in the arcade version. The console versions would gave their identities in the manuals though. For the arcade version of Double Dragon 3, the licensed soundtrack gives out the names of the bosses in their individual themes (Jim, Li, Ranzou and Giuliano).
The final boss in the second NES game, who is simply known as the "mysterious warrior".
The other two enemy characters exclusive to the NES version, "Ninja" and "Migiude" (which is Japanese for "right arm", or more appropriately "right-hand man"), only have official designations instead of names, but those two are just elite mooks and not unique characters.
Obvious Beta - Super Double Dragon. Even the more complete Japanese version (Return of Double Dragon) was clearly rushed for release. The second half of Mission 7, absent from the US version, is very unfinished (e.g. Bottomless Pits you can't fall into, stairs you have to jump up). Other things Dummied Out of both versions include the proposed true Final Boss battle with Duke's shadow, the Conveyor Belt-O-Doom in the airport baggage claim that would lead to a Bottomless Pit, the warehouse section of Mission 5, and the collapsing bridge at the end of Mission 6. Many music tracks were left unused (a few which can still be heard in the Japanese version's sound test) and Marian, who is mentioned in the manual and shown in two pieces of artwork, never actually appears in the game (she would've been a policewoman like her comic and cartoon counterparts).
One Steve Limit - The names "Billy", "Willy" and "Williams" are all variants of the name "William" (although, to be fair, "Williams" is technically a surname).
Then there's Bolo and Abore, the giant mooks from Double Dragon II: The Revenge, the former being an almost exact clone of Abobo from the first game, but with long hair (to the point that he's even listed as "Abobo" in the licensed Mega Drive port).
The arcade version of Double Dragon 3 has a "Jim" as the first boss (not to be confused with the heroic Jimmy Lee) and a "Li" as the second boss (who is unrelated to the Lee Brothers). Then there's Sonny (the Player 3 Lee brother) and Sunny (the Player 2 Urquidez brother).
Palette Swap - In the original arcade game, there are only seven unique enemy characters and two of them are just head-swaps of other characters (namely of Abobo and the Lee brothers). The game simply recycles the same set of enemies for each stage by changing the main palette for all the mooks, including the occasional black-skinned variants. The third boss is also a green skinned palette swap of the first boss, who is nothing more than a black-skinned head/palette swap of Abobo with a Mr. T-like beard and mohawk. The other games in the series also featured palette-swapped versions of the same enemies.
The end of Mission 1 in the first arcade game has a billboard for Nekketsu Koha Kunio-kun, the Japanese version of Renegade and Technos Japan's previous beat-'em-up, in the building just before the first boss battle.
The red sports car from Road Blaster (a Data East laserdisc game, ported to the Sega CD as Road Avenger), a game designed by the same director (Yoshihisa Kishimoto), can be seen inside Billy and Jimmy's garage at the start of the first stage. In the second arcade game, the sports car is replaced by the helicopter from Thunder Storm (aka Cobra Command, Kishimoto's other FMV game he did with Data East).
Punched Across the Room - The Lee Brother's Hyper Knee and the Mysterious Warrior's backflip kick can send anyone flying quite far.
In Neon, the One-Inch Punch special move does a short-range attack that knocks enemies backward.
Sdrawkcab Alias - The final boss in the NES version of Double Dragon III is called Queen Noiram (who is actually a brainwashed Marion). Averted in the other versions (including the Famicom one), when she is actually a revived Cleopatra.
Sequel Difficulty Spike - The arcade version of II has more powerful bosses than the first game, only partial health recovery between stages (as opposed to full health recovery like in the first game), and no bonus lives (you're stuck with what you start with). Moreover the game's time limit is adjustable and the default settings has the game on the second fastest time limit with the second hardest difficulty and only two lives, which makes the third stage hard to complete on time and the fourth stage almost impossible. All the transition sequences between stages are now done by elevators, making it impossible to carry weapons between stages unlike in the first game.
The NES version of the third game is also considerably harder than the previous installments at first due to the omission of a lives system. If the player dies in the first two stages, the game ends. However, the additional playable characters introduced in the later stages serve as extra lives on their own and the player gets a single continue for the final two stages.
She's Got Legs - Marian in both the original series and the Neo-Geo fighting game.
The red sports car inside Billy and Jimmy's garage in the original arcade game is the same one from the laserdisc arcade game Road Blaster (aka Road Avenger), an earlier game by Double Dragon creator Yoshihisa Kishimoto.
A billboard in Mission 1 features an advertisement for Nekketsu Kōha Kunio-kun, the Japanese version of Renegade and predecessor of River City Ransom.
The second arcade game replaces the sports car inside Billy and Jimmy's garage with the helicopter from Cobra Command, another laserdisc game also directed by Yoshihisa Kishimoto.
The GBA version includes a freeway battle atop moving semis with suit-clad enemies who straighten their ties between attacks. If it's not a Shout-Out to The Matrix Reloaded, then it should be.
Shout-Out Theme Naming - The Lee Brothers, along with recurring mooks Williams and Rowper, all take their names from the three main heroes of Enter the Dragon. The name "Billy" is also a reference to Billy Lo (Bruce Lee's character from Game of Death) and the female mook Linda shares her name with Bruce Lee's widow Linda Lee Cadwell.
In the second game, there's an Abobo-like Giant Mook named Bolo, a reference to Bolo Yeung (who played one of Mr. Han's two henchmen in Enter the Dragon). The arcade version even has a head-swapped variant of Bolo who was given the name of "Oharra" in the Mega Drive port (Mr. Han's other henchman).
Sō-setsu-ken, the fictional martial art style of the Lee brothers, is named after Bruce Lee's self-developed style called Jeet Kune Do (Sekkedō in Japanese). Whereas Jeet Kune Do is the "Way of the Intercepting Fist", Sō-setsu-ken means "Fist of Twin Interception".
In the third arcade game, the Lee brothers are joined by the Oyama, Chin, and Urquidez brothers, named after Mas Oyama, Jackie Chan, and Benny Urquidez in that order.note "Chin" is the Japanese pronunciation of Jackie Chan's Chinese surname.
The second boss in the arcade version of Double Dragon 3 is named Li Chenglong, a combination of Bruce Lee's surname and Jackie Chan's Chinese stage name (Cheng Long)
Invoked literally in the third arcade game, where the main characters were grouped by teams of siblings. The Lee brothers are joined by the Urquidez, Chin and Oyama clans.
Side View - Some of the stages and areas in the NES games are set from a side-view perspective and don't feature depth movement. They usually involved platform-jumping in some capacity like the cavern areas in Mission 3 of the first NES game or Mansion of Terror in the second. The Game Boy version also switches to a side-view in some areas.
Rowper, one of the enemy mooks, had his name spelled as "Lopar" in the translated manual for the NES version. However, the character's name is actually meant to be a reference to John Saxon's character "Roper" from Enter the Dragon. The name "Roper" and "Lopar" are also used for two different enemies in Battletoads & Double Dragon and neither resemble the Rowper from the original game (one of them being a misnamed Machine Gun Willy).
Linda's name is spelled "Rinda" in the promotional brochure for the Famicom version.
Chin Taimei's name was shortened to "Chintai" in the NES version's manual.
Marian's name is sometimes spelled "Marion" depending on the game. The manual for the Master System version spells it "Mary-Anne" as well.
Even Sōsetsuken, the fighting style of Billy and Jimmy, has been subject to spelling variations, with the manual for the NES version using the spelling Sosaiken (since the second kanji can be pronounced both ways).
The manual for the Neo-Geo version spells Burnov as "Bulnov" and Dulton as "Dalton."
Spiritual Successor - Rage of the Dragons was intended to actually be a sequel to the previous Neo-Geo game, but because Evoga (the developers) were unable to secure the rights to the Double Dragon franchise, the game is instead a loose homage, starring brothers Billy and Jimmy Lewis instead of Lee, plus an Abobo-like sub-boss named Abubo.
Double Dragon itself was a spiritual successor to Renegade.
Super Mode - In the SNES game completely filling the Charge Meter activates this, which makes your attacks more damaging and instantly knock downs enemies.
Suplex Finisher - The Lee Brothers got a German Suplex in their moveset in the third arcade game.
Team Shot - The ending of the third arcade game ends with a group shot of Billy and Jimmy, along with three of their allies (Chin, Oyama, and Urquidez). The same art was actually used as the basis for the cover illustration of the Famicom version, only with Oyama and Urquidez replaced with Yagyu.
Temple of Doom - The final stages of I and II. The NES version of the latter had a more literal Temple Of Doom.
Theme Music Power-Up - The final battle in the original arcade game (and in some of its ports and remakes) uses the title theme as background music, as does Return of Double Dragon (the Japanese version of Super Double Dragon). Once the final boss of the second NES game is low on health, the creepy theme is replaced by a more epic theme.
There Was a Door - Abobo and Burnov do this several times in the first two games.
Throw a Barrel at It - The oildrums, along with cardboard boxes and giant rocks, can be picked up and thrown by both, the player and certain enemies (depending on the game, but usually Rowper always uses them).
Took a Level in Badass: Marian in the Neo-Geo version, where she's not only a selectable fighter, but is one of the higher-tier characters in the roster.
Turns Red - In the SNES game, if the player performs a throw on Williams or Rowper, they will get angry and will move faster and hit harder.
Wanted Poster - In the original arcade game, the wanted posters for the first two bosses (Bolo and Jeff) can be seen in the beginning of Mission 1, offering a reward for $10,000 each. Willy's wanted poster can be see next to Jeff's in Mission 3, which shows that his bounty is $100,000, ten times greater than either of the other two.
The same wanted posters for Bolo and Willy also appear in the arcade version of the second game, but Bolo in that game underwent a complete sprite swap, no longer sporting his original Mr. T-style look that his poster depicted him with.
Would Hit a Girl - Pretty much every guy in the game, from the opening intro where Williams sucker punches Marian in the gut and carries her off, to Billy and Jimmy beating the crap out of the whip-wielding Lindas.