It all began in '94. Kept on rollin' in '95. The pieces were in place in '96, and it came to an end in '97. But now it comes, and here we go. KOF is here again. Nothing's gonna stop it 'cause it's 1998!
The original King of Fighters arc (known alternatively as the Rugal Saga), which focuses on notorious crime lord Rugal Bernstein and his attempt to establish himself as the world's strongest fighter by staging a grand tournament and inviting contenders from all across the globe. It is strongly associated with the artist Shinkiro.
The Orochi Saga arc, which concerns Kyo Kusanagi (the winner of the first King of Fighters tournament) and a thousand-year blood feud with the Yagami family, who have gained demonic power thanks to a pact with a being known as "Orochi." Shinkiro continued to be the lead artist.
The NESTS Chronicles arc, about the eponymous organization and their conspiracy to create weaponized clones of the most powerful warriors in the world. As Kyo is absent for the majority of this arc (he doesn't show until the end of '99 and remains a supporting character for the remainder of the saga), the main protagonist is a new character called K' (pronounced "Kay Dash"). It is strongly linked with the artist Styleos.
The Tales of Ash arc, which introduces androgynous French pretty boy Ash Crimson as the new main character. The story involves a sinister plot to capture the powers of the Kusanagi, Yagami, and Kagura clans and use them to seize the sealed power of Orochi, as well as the question of just whose side Ash is on. It had Nona and Falcoon as artists. It also experienced a change of hardware platforms multiple times, the first in-game Art Shift ever, and turmoil in the parent company, but managed to get on Steam in the end.
More detailed summaries of each arc (and the individual games) can be found in the Analysis section).The games were initially released on the (ridiculously expensive) Neo Geo home arcade system, so they had a hard time catching on with North American home gamers, but remained very popular in Japan, as well as with arcade gamers worldwide. It released new editions of the game every year with Madden-like regularity, introducing new characters and rosters into the storyline, while the old characters have seemingly retained their basic sets of special moves throughout the series, probably to dodge the problem of the older games being So Last Season.In addition to the thirteen games of the main KOF storyline, there are multiple spin-offs, remakes and "dream match" titles (that combine all the characters of that particular saga into one game).These include Maximum Impact, a 3D fighting game series which takes place in an Alternate Continuity, right down to having characters not featured in the main KOF storylines; The King of Fighters: KYO, an RPG that ties the events of '96 with '97 and indulges in Kyo and the background of his clan; a Bullet Hell spinoff called KOF Sky Stage for the Xbox Live Arcade; The King of Fighters-i 002, an iPhone game that ties into XIII; and The Rhythm of Fighters, a Rhythm Game spinoff for iOS.Aside from fighting games and tie-ins, there were the rather infamous Dating Sim games for mobiles and Nintendo DS, Days of Memories allowed the player character to venture in Southtown and date most of the fighting divas from the series (andfromothers); later versions also allowed a girl player character to date the male fighters as well.This is the character sheet. Be warned, though: in this series, SNK most certainly ran away with the concept of Loads and Loads of Characters.
Alternate Continuity: The Maximum Impact series, the EX series, the R series, Neowave (the latter of which has no proper story), and Days of Memories (with changes going up to the characters' personalities themselves).
KOF itself is an alternate continuity to both Fatal Fury and Art of Fighting. This was intentionally done so that SNK could pit characters from both series without having to reconcile their ages (since Art of Fighting was set ten years before Fatal Fury).
Amazon Brigade: Women Fighters Team, in its various incarnations. In 2003, the High School Girls Team replaced the Psycho Soldiers Team, which consisted of Athena, Hinako, and Malin.
Badass Crew: Most of the (earlier) teams fit this bill (i.e. Team Japan, Art of Fighting Team, Fatal Fury Team, Ikari Team, etc.), as many of them are family members and close friends who have known each other for a good deal of time and decide to team up. More recent examples would include Team Korea and the K' Team. At this point, most of these teams have at least two or three characters that function as True Companions.
Badass Family: The Kusanagi, Sakazaki, and Howard families, natch.
Also the Bogards, even if there's just two brothers by now.
Bar Brawl: The Women Fighters Team's ending in XIII is a particularly catty example. At the Pao Pao Café, King, Mai, and Yuri, all smashed from their victory celebration, start bickering with each other over who's the best fighter on the team, which in turn strikes a nerve with B. Jenet, Kasumi, Malin, and Xiangfei. This leads to a free-for-all overlooked by an amused Vanessa (who muses to herself that "it's nice to be young"), the worried pair of Hotaru and Hinako, and an utterly distraught Richard.
Battle Trophy: Rugal Bernstein: it's revealed in his debut game that he preserves the bodies of the countless martial artists he's defeated over the years by subjecting them to a grisly liquid metal bath, making them living trophies.
Bishōnen: Half of the male cast is made up of pretty boys. Nagase, the tech-head ninja from Maximum Impact 2, dislikes each and every last one of them.
"Blind Idiot" Translation: Most of the games up to 2002 will have at least one totally bizarre line that becomes almost way too funny. At a serious scene, just one slip up in translations and BAM: INSTANT NARMAGE.
Calling Your Attacks: Almost everyone. Very often subverted when the characters yell something other than the move's name (like Iori); averted by the less talkative characters (Daimon, Leona) and Orochi, whose moves didn't even had actual names until '98: Ultimate Match.
The Cameo: The entire gamut is enough to probably warrant its own page.
To be fair, all of the "dream match" titles are like that. '98 and 2002 (UM) have no bearing on the titles that come after them. The anomaly here is rather where the placement of the dream match occurred (that is in the middle of a saga, rather than as a bookend that brings back the cast from the whole saga; though it was clearly not intended to be a dream match anyway).
Character Customization: While its still impossible to change costumes in XIII because of 2D, SNK have been very creative with color palettes (Robert Garcia with very convincing Terry Bogard palette for example), especially with skin color and skintight clothing (most notable are "no pants" Yuri and Raiden's many "costumes"). And then, as soon as the arcade version was released, it's been revealed that there's alternate palettes that give certain characters actual headswaps: Yuri gets her long hair back, Raiden loses his mask (revealing that he is, in fact, Big Bear), and Takuma gets his Mr. Karate tengu mask back.
The console version adds to this with Kyo getting his old '94-'98 school uniform back (and this is without counting his DLC form which comes with a whole new costume—his NESTS-era look, to be specific—altogether).
On a lesser scale, the PS2 ports of KOF games from Neowave up to 2002: Unlimited Match had a colour edit feature allowing players to create their own custom palettes. KOF XI onward let you edit their special moves' colours too.
Character Roster Global Warming: As far as Mighty Glaciers go, the series started with Ralf, Clark, and Chang. It took them about six years to add Maxima, a year to add Seth, three years to add Tizoc, and about another six to add Raiden.
Charles Atlas Superpower: Partially averted, as many characters have incredible strength and powers due to their bloodlines. On the other hand, others are powerful simply because they trained.
Cherry Tapping: In XIII, if you defeat an opponent with a weak punch / kick, they will have an alternate defeat animation wherein they would fall to their knees.
Clone Army: The King of Fighters '99 had the endgame involve armies of Kyo clones being staged across the world by Krizalid in an attempt to take over the world. Even if he were to succeed, which he did not, the governing body that created him had shut down his connections and the endboss of the next game, Zero, personally terminated Krizalid because of how out-of-control he got.
Clone by Conversion: K' is one of Kyo. Although he's still considered a clone despite only being injected with Kyo's genes and retaining his own appearance.
Comic-Book Time: After '95, SNK froze all of the ages of their characters in order to keep the cast roughly youthful. While there are a few illusions of the passage of times (such as Kyo changing his outfit to show that he's dropped out of high school), the earlier characters remain in their teens and twenties whereas most of them should be about a full decade older. This also extends to cameo characters and newer entrants. This is why characters like Kim's sons Jae Hoon and Dong Hwan from Garou, as well as fan-favorite Rock Howard (SNK Playmore's desire to save Rock for the Garou sequel which will probably never come to pass aside) will probably never make a playable appearance in a future 2D KOF; they appear as children and will stay that way unless there is some sort of retconPlot-Relevant Age-Up involved.
Commuting on a Bus: Due to rotating protagonist duties, the main heroes of each Story Arc are bumped down a few notches in plotline importance to make way for the next guy, whom the task of wrapping up the new saga falls to. The old guard still contributes to the overarching story (for example, K' and his team fight Mukai in 2003 and the Three Sacred Treasures remain pivotal players throughout the Tales of Ash), just not as heavily as back when they were the headliners.
The King of Fighters Orochi Hen (PS2): A Japanese release comprising of '95, '96, and '97: the Orochi Saga.
The King of Fighters NESTS Hen (PS2): Same as above, only it includes '99 (plus the Dreamcast port, '99 Evolution), 2000 and 2001. Basically, the NESTS Chronicles.
The King of Fighters Collection: The Orochi Saga (PS2, PSP, Wii): The US and European equivalent of the first collection, only it also includes the series' progenitor '94 and the popular '98. This package also includes a Challenge mode, but lacks the online mode, soundtrack selection, and customizable palettes from the Japanese compilations.
It's also been stated that members of the Yagami bloodline have a tendency to die young, most likely due to the Riot. Puking up all that blood on a regular basis can't be healthy...
Specifically, mixed bloodlines (i.e. Leona and Iori) can't fully control the power of Orochi, making it easy for Orochi or one of Four Heavenly Kings (Goenitz, Yashiro, Shermie, or Chris) to induce a violent, mindless rampage.
... but that's not the case with Vice and Mature, who not only appeared in '98 and 2002, but also XIIInote which is actually a canonical installment as full-fledged members of Iori's team only for the duo to fade into darkness again after they become champions.
Depending on the Artist: Iori's hair is either a gravity-defying pompadour or a more realistic bang that covers part of his face. Sometimes it's in-between the two styles!
K' usually has a (relatively) normal hairstyle, disheveled with a fair amount of bangs. This is consistent throughout the series in terms of sprites and most artwork, but his hair will sometimes appear thick and bushy like a miniature afro, slicked, or even straight-up Shonen Hair.
To his defense, at the time Orochi has just been incarnated into Chris' body, therefore not at his full-strength. Yet, the Three Sacred Treasures' attack on him did little damage, and Kyo was only able to defeat Orochi with the help from (Blood Rioting) Iori and Chizuru.
Difficulty Spike: Several games in the series suffer from this, but the three most egregious examples would probably be in '94, '96, and XI. If you reach the first cutscene (in '94), face the Boss Team (in '96), or make it to the sub boss (in XI), expect things to take a turn for the worse.
Distracted by the Sexy: Only in the comical, non-serious "ending" of 2002, though: Shermie makes several suggestive poses and many male characters (including Andy Bogard!) run around trying to get a good look. Clark just runs up and tackles her.
Clark and Ralf used to be basically the exact same character; little more than headswaps. Over time, they evolved to the point it was downright bizarre to think they were ever similar (Ralf likes to punch things, Clark tosses you around). Fan reaction was extremely negative when Clark was brought back to the rank of "Ralf 2" in XII.
Mature and Vice. The former is more speed-oriented, while the latter is a grappler; they only share one move, Deicide(two if you count their XIIINeo MAX).
The Kyo clones, whose differentiation came in 2002: Unlimited Match.
Kyo and Iori were actually Ryu and Ken in '95note justified in the backstory as their clans, before the Yasakani made a deal withOrochiout of jealousy, pulled a Face-Heel Turn, and changed their name to Yagami, developed their fighting styles together but then became wildly different in the next game; in fact, when Iori lost his flames and became a more physical fighter a la Kyo post-'95, Kyo went back to his old moveset.
The console version of XIII then added the original flames Iori and "rekka" style NESTS-saga Kyo as DLC playable characters thus restoring the Kyo-Iori side of this trope two-fold (so you can have old "rekka" Kyo versus new "melee" Iori or new/old "fireball" Kyo versus old "flames" Iori).
Doomed by Canon: The New Faces/Orochi Team die in their ending, for crying out loud!
In fact, there's a 90% or greater chance that the main villains of each title will die by the game's close.
Downloadable Content: XIII has 3 characters made DLC, all three of them being different versions of existing characters basically serving as nostalgia.
"Iori with the Power of Flames" is Iori as he used to be, using his old moveset from other KOF games before Ash stole his powers. He also claims the SDM version of his Ya Otome from KOF '99, his Yamisogi DM from KOF 2000, and his Neomax is the Homurahotogi HSDM from 2002 with a much, MUCH larger explosion that triggers the very moment he grabs your head (Unlike in 2002 where there was a brief pause when he did.)
"NESTS Kyo" is Kyo in his KOF '99 outfit with his signature "rekka" moveset from '96 to XI. He loses his aerial Orochinagi DM but reclaims his Mu Shiki DM. His Neomax "Totsuka" is a whole new move involving a charging fire punch that causes a gigantic explosion.
"Mr. Karate" is Takuma in his classic Art of Fighting boss persona (he has it as an alt. costume of sorts but here it's a legitimate EX moveset). His moves (and by the looks of things, his personality here) are based around Serious Mr. Karate from SNK vs. Capcom: SVC Chaos while his Neomax is a whole new move starting with a punch and ending with a flashy, explosive karate chop with Mr. Karate powered by the golden spirit of a real tengu.
Dramatic Wind: A few characters have these in their intro or win poses. This includes Kyo and Iori's special introduction in 2000 which is made funny if the wind in one of the backgrounds is blowing the other way around.
Dream Match Game: KOF '98 was the Trope Namer, featuring every character from the Orochi Saga including the ones that were meant to be dead, such as Vice, Mature, the New Faces Team, and Rugal (including a buffed version of his Omega form). Some characters such as the Boss Team from '96 and the other two bosses didn't make the cut... until '98: Ultimate Match, which re-added Eiji, Kasumi, Geese (and gave him a toned down Nightmare mode as his EX moveset), Krauser, Mr. Big, Orochi Iori, Orochi Leona, Goenitz, and Orochi, as well as a few new EX versions of various other characters, some new stages and familiar music from previous SNK games.
2002 is one for the NESTS saga as well, including bringing back the '97 New Faces Team and Rugal as well as introducing Kusanagi... who was essentially another Kyo clone with Kyo's classic moveset from '94 to '98. Then came 2002: Unlimited Match which brought back everyone else that didn't get in, making for a HUGE cast of characters. Including the previous NESTS bosses, AND Goenitz and Geese from the PS2 port of 2002. Oh, and they gave Geese his Nightmare form back, and buffed it beyond belief. Only Orochi Iori didn't make it in from the PS2 port, though his sprites were found in the game's coding by hackers.
Neowave is essentially an alternate 2002 as it too has no plot. It does swap out some characters and re-insert King and Shingo, as well as bringing back Jhun Hoon and Saisyu Kusanagi, and as a strange inclusion, has Geese Howard as its final boss... or rather, his younger self from Art of Fighting 2. The PS2 version re-added certain 2002 characters such as Angel and Rugal.
Additionally, the ability to run and roll didn't become staple gameplay elements until '96 (which is a main factor in why the third game is generally seen as the point where the series took off). In the first two games, characters could only hop forward and sidestep dodge, respectively. The power gauge also operated somewhat abnormally by fighting game standards throughout the Orochi Saga: from '94-'96, as well as '97 and '98's Extra Mode, the gauge had to be manually charged and otherwise would only fill up when taking damage or blocking specials and DMs. Upon reaching MAX, the power gauge functioned identically to the POW/Rage Gauge, meaning that stocks couldn't be held, the player dealt more damage, and the bar would empty completely after a certain period of time.
Easter Egg: In XI, certain characters have alternate taunts depending on who they're facing. Iori has specific taunts for Kyo and Ash. Ash has the same in regards to Kyo and Iori. Oswald happens to have three different poses for his taunt, although it's not character-specific. The special intros and idle animations throughout the series could also count. Try holding down with Bao for example.
In XIII, Yuri is the only character to have three variations of her taunt/personal action: she either a) looks at the screen, b) looks at the screen with bulgy eyes (resembling a stock shocked anime expression), or c) she flashes a V-sign similar to her artwork.
Embedded Precursor: Of sorts. Both '98: Ultimate Match and 2002: Unlimited Match have the original Neo Geo AES versions they were remade from included, although only in the PS2 version in 2K2UM's case.
Enemy Mine: Kyo and Iori teaming up occasionally; Gato with the Outlaw Team in 2003 (though Gato has no friends or enemies, from his point of view).
Four Is Death: Goenitz, Yashiro, Shermie, and Chris are the Four Heavenly Kings of Orochi. Mature, Vice, Yamazaki, and Gaidel (Leona's biological father) are the Four Earthly Kings of Orochi. They complete the Hakkesshu that represent the eight heads of Orochi.
The Hizoku clan is divided up into four subgroups, with the best assassins and leaders of those groups collectively known as The Four Devas (not those ones). Three of the Devas are NPCs who primarily appear around Lin, but the fourth was Ron, father of Duo Lon and Xiao Lon, who formerly served as the head of the entire clan until he betrayed them to lend his services to NESTS.
Game Mod: No matter which Neo Geo installment of the series you pick, there's always a hack of it. Primarily they tend to make bosses playable though some add new arenas, graphics and bump up character's attacks to ludicrous levels. Sometimes you get the odd mod that adds new characters, such as a hack of the arcade 2002 that adds the console port's extra characters (King, Shingo, Orochi Iori, Goenitz and Geese).
Genre Savvy: Iori's teammates in 2001 (Vanessa, Seth, and Ramon). They're well aware that Iori has a history of attacking his teammates, as seen in '95 and '96. What do they do about it in the Yagami Team ending? Attack him first!
Ground Punch: Some characters do this in order to create a short-lived barrier or projectile. The most notable example of this is Terry Bogard, who retains this trick from his series of origin.
Hidden Depths: Take the time to find the official bios for each character, and you'll be surprised by some of their hobbies and other aspects of their lifestyles. For example, Kyo is literally a Warrior Poet (albeit a poor one) and several characters are quite the talented musicians.
Hong Kong Dub: Largely played straight with the Maximum Impact dub. Inverted in that the original Japanese audio doesn't always sync properly with the lip movements either, although it's far less frequent.
Iconic Sequel Character: The King of Fighters '95 introduced Iori Yagami, The Rival to the game's protagonist, Kyo. His popularity, which was spurred by his appearance and personality, managed to make him so recognizable that he not only kept being used as an icon for the series in later iterations, but also became a major Breakout Character.
Idle Animation: K''s is notable in that it doesn't loop, which is unique for a sprite. To add to that, his eyes close progressively slower till he's outright fallen asleep. The only way to see him in his fighting stance again after he's put his hands in his pockets is to move him from his spot. Other characters have slight idle animations too such as Clark wriggling his fingers to keep them from stiffening, Ralf hopping back and forth in place, Leona standing straight, and Andy, who would change stances a few times in his animation, one of which was his classic stance from older Fatal Fury games. Bao has a variant of this if you hold crouch, where he'll start drawing on the ground and then fall asleep.
This even extended to the characters on your team who waited their turn on the sidelines (from '94 to '98) as you fought. The combatants who had yet to fight would stand and react accordingly (positive gestures if you landed a hit, not-so-positive ones if you were getting your block knocked off); KO'ed fighters would sit there silently in a defeated slump, only acknowledging the ongoing fight if their teammate(s) managed to avenge them. If you were stunned or being grabbed by your opponent and nearby your teammates, you could mash buttons and one of them could jump out and briefly attack your enemy.
I Was Young and Needed the Money: When SNK Playmore was in dire need for some quick profit in 2005, they pulled a desperate gamble, make a game to gather many as fans as they could, but another fighting game wasn't their aim, seeing how many Bishoujo and Ms. Fanservice girls they had in The King of Fighters and other fightinggamesaswell, a series of dating sims were made for mobiles and later ported over for the Nintendo DS. The series was called Days of Memories with a subtitle for each new installment, it proved to be rather successful as seven mobile games and two rereleases for Nintendo DS were made until 2008.
The original intent was to only aim at men with the female fighters as obvious interests for the average Player Character, but the series proved to worthy of their time and SNK Playmore started to whore out male fighters for female fans of the franchise as well. The initial roster for girls was composed of: Athena Asamiya, Kasumi Todoh, B. Jenet, King, Mai Shiranui, Yuri Sakazaki, Leona Heidern and Kula Diamond, and the men were: Kyo Kusanagi, Iori Yagami, K', Ash Crimson, Terry Bogard, Rock Howard, Alba Meira and Ryo Sakazaki, eventually after all the seven installments the choices grew to arguably as many popular guys and girls as any KOF "fan" would like to date. Of course this also includes massive doses of Alternate Continuity, Hand Wave, and Retcon, specially in regards to canon/teased love interests or other relationships, in order to make the games work.
Leaning on the Fourth Wall: While several Victory Poses seemed to be aimed at the player directly (such as Yashiro giving a sly pointer gesture, Kim's Twinkle Smile, Benimaru's "I love you" and "Thank you," Shermie blowing multiple kisses, etc.), but they're also combatants in a (usually) televised, wildly popular international fighting tournament, so it's possible that they're also appealing to their fanbase.
Left Hanging: The Maximum Impact series seems to be heading this route. 2 ended on a Sequel Hook, Regulation A was simply an Updated Re-release, and Regulation A2 was cancelled. Plans for a third game seem unlikely.
Basically everything surrounding the Dragon Spirit: what exactly it is, how it intertwines with the overall plot or other characters, etc. Ron has said that the power is so absurd that it makes all of NESTS look like nothing and yet this plot point never achieves to be as important as it is implied. It is said a the that Kensou has mastered the control of the Dragon Spirit, but still no major changes can be seen through his power level (his personality is slightly more serious but not too much), taking account at how leagues more powerful he should have been if he truly mastered the control of his powers.
Lightning/Fire Juxtaposition: Before the start of the series Kyo and Benimaru were rivals, but nowadays have become great friends. They're based of a Japanese saying: "Lightning strikes ground and creates fire" (with their friend, Goro Daimon, as the "ground").
Loads and Loads of Loading: The Neo Geo CD ports of the games, which have loading times so frequent and so ridiculously long (20 to 30 seconds, due to the CDs' slow single speed drive) that they slow the pacing of all the games to a crawl.
Mirror Match: Not just a game mechanic, considering the number of Kyo clones there are. He even complains about how many of them there are in a few games set after the NESTS Saga (namely KOF XI where he jokes that he could make a baseball team out of himself).
The Movie: There's one, starring Ray Park as Rugal... and let's leave it at that.
Nebulous Evil Organisation: NESTS, as well as Addes (and its sub-syndicates/branch organizations the Children of Kokaviel, Kusiel, Mephistopheles, and Belphegor) in the MI series. Those from the Past started as this, but quickly became a Standard Evil Organization Squad as time progressed.
Not Just a Tournament: The game in a nutshell, most prominently during The Orochi Saga ('95-'97) and The Tales of Ash (2003-XIII), where the primary motive of the baddies is to unsealOrochi (although for varying, but no less equally evil purposes). This has happened so frequently that characters start asking why there can't be a regular fighting tournament that doesn't serve as the instrument for The End of the World as We Know It every once in a while.
Numbered Sequels: Until recently, all of the games had the "The King of Fighters" title, followed by the year the game was released. This tradition stopped with the release of XI, which was released two years after 2003. There is also a bit of confusion about this, since KOF: Maximum Impact 2 was entitled "The King of Fighters 2006" in North America.
Obvious Beta: XII's home version was released with very spartan single-player features (only five fights and no boss), a poorly regulated and hastily-patched online mode (to the point of being unplayable), and massive Game Breaking Bugs. Studious crackers have found files on the game disc regarding Dummied Out characters.
Oddball in the Series: It seems that this title would originally go to 2001 with its bizarre spin on the Striker System (your team can go anywhere from all four characters to only one member with three Strikers), the low-quality, highly-repetitive, techno-style music that lasts for all of 30 seconds, its lukewarm conclusion to an already controversial saga, and (most of all) "lovable" Igniz, one of the cheapest bastards in fighting game history (to put this into perspective, he was the former posterboy for SNK Boss), but you could make a case for the bare bonesXII too.
Off Model: Since the default sprites are used since '96 and the style of animators keeps evolving or the animators are changed, this is bound to happen, starting with new attacks that looks a little different in style (some attacks in 2000) to very noticeable art clash (starting with 2000 newcomers, although '99 newcomers are an arguable transition).
Parts Unknown: Unlike most fighting games, which mostly restrict this trope to bosses, a good chunk of the characters in the series have "unknown" listed against their birthplaces - 26 out of the total 90 (non-powered/cloned) characters, in fact.
Practical Taunt: In earlier iterations, taunting lowers the other player's power bar (though it does the opposite in more recent installments).
Kyo Kusanagi Classic, a throwback version of Kyo with his Orochi Saga appearance and moveset introduced in Maximum Impact 2, is able to, in a direct nod to the pre-'99 installments, manually charge his super meter if the player holds down the taunt button.
Put on a Bus: This happens a lot. You can't fit 80+ people in one game.
The American Sports Team, who appeared in the first game and has only been back in a non-striker fashion only once for the "Dream Match" game, The King of Fighters '98 (which still had missing characters, like Eiji, Kasumi and the '96 Boss Team! — at least until Ultimate Match).
Leona skipped XI.
Andy Bogard skipped 2003 and XI.
Considerably, May Lee, K9999, Foxy, and Angel haven't been seen since 2002.
... while Bao, King, Jhun, Hinako, Xiangfei, Shingo, Lin, and Foxy, for some unrevealed reason, skipped the original 2002! King and Shingo, however, were brought back to home versions. As for the others... expect background cameos.
Not to mention that 2001 was the only canon installment to include Foxy as a playable character. Officially. Save for 2002UM.
Hinako. Put on a bus since 2003.
The current saga was notable in that several characters that were mainstays throughout the Orochi and NESTS sagas (i.e. Andy, Mai, Robert, Leona, Chang, Choi, Chin, etc.), were dropped from the roster in either 2003 or XI. Not that most of 'em didn't come back in either the home port of XI, XII, or XIII...
Shingo hasn't been around since XI.
Quirky Miniboss Squad: The Outlaw Team from 2003 is made up of sub-bosses from the Fatal Fury games (and Gato) — Billy Kane, Gato, and the Ax-CrazyKnife Nut Ryuji Yamazaki. It was like this in '97 as well, only with Blue Mary completing the threesome with Billy and Yamazaki (Gato would not be created until 1999's Garou: Mark of the Wolves).
'97, 2001, and 2002 had the New Faces and NESTS teams. Especially 2002.
Real Is Brown: For no reason, 2002 and 2003 had desaturated colors in their stages.
Relationship Values: Rare non-RPG example, and stealthily inserted at that. From '94 all the way up to '98, the teammates you chose affected who would actually be willing to contribute to the next teammate's meter stock, or jump in and initiate a Help Attack if their partner in the ring was dazed or being grappled. Allies are more likely to do so if the characters aren't hostile to one another and/or have strong ties (familial, romantic, or platonic) in canon. However, not all characters abide by this rule. Iori, for example, will never bust his neck to help out a teammate, period.
You can actually see everyone's attitude towards how their team is set up by holding start at the Order Select screen in '98 (depicted by either an angry, neutral or happy smiley). Beware: Some versions of the game randomize everyone's attitude according to the system's internal clock.
To add to the insanity, the Dreamcast port, '99: Dream Match allows you to change everyone's attitude the more you group them together, which means even Kim will help out "evil" characters like Vice and Mature if you play them as a team often enough.
So Last Season: Subverted: the rosters rotate with every new season, but the special moves rarely do. That being said, don't expect movesets to be entirely static throughout the series' run.
Some Dexterity Required: The series had a problem with this early on. Then there's the legendary Raging Storm: Down-Back, Half-Circle Back, Down-Forward. There's a reason it's called "The Pretzel." Most games starting with '96 averted this, but SNK still throws curveballs from time to time. K9999's inputs are also ridiculously difficult as are Duck King's in XI. The Raging Storm is notoriously difficult for the sake of nostalgia.
As well as Aya and Hermione, Rugal's secretaries from '98, who replaced Mature and Vice after they became ascended extras.
Tag Team Twins: Pre-final boss fight in 2003 against Chizuru and Maki Kagura who fit this trope just exactly: not only they're literal twins and they both fight in a two-member tag team (whereas three was the default number), they also share the same lifebar.
The Dev Team Thinks of Everything: In XI, one of the stages is set in an alleyway outside of the Pao Pao Café in Southtown. If you hang out in the center and right areas of the stage, nothing exactly spectacular goes on besides some civilian spectators cheering you on. Move far enough to the left, however, and a motorcycle comes barreling down the street—the very same road the combatants were obstructing earlier.
Three Round Deathmatch: One of the first notable aversions in the genre. The team-based gameplay of '94 ensured fights always lasted at least three rounds and can stretch to five. 2003 and XI, being tag-team games, do not use rounds at all and simply have the fighters battle until one team has no more characters it can field. Installments after '94 did include an option for traditional 1v1, "first to two fall" fights, however.
Tornado Move: Joe Higashi's moveset includes multiple attacks of this nature, beginning with his "Hurricane Upper" and "Twin Hurricane", which are two of his basic attacks. Followed by his (HS)DMs "Screw Upper" and "Exploding Screw Upper." He first gained "Double Cyclone/Malestrom", which unleashes two Screw Uppers at once, in Capcom vs. SNK 2. And last, but certainly NOT least, there's his NEO MAX, "Screw Straight"! They call him "The Human Storm" for a reason.
Ultimate Match got its own rerelease with the PGM 2 version, which brings in some balance fixes and new moves.
After XIII was given a console release (complete with extra content and DLC), the arcade version received an upgrade entitled The King of Fighters XIII Climax, which features all of these bonuses.
Up to Eleven: SDM/HSDM/MAX2/LDM/Neo MAX variants of existing specials and DMs tend to be a mite bit more grandiose than their normal versions.
Video Game Long Runners: "It all began in '94..." All joking aside, the series includes thirteen titles (not including Updated Rereleases like '98 Ultimate Match, 2002: Unlimited Match, and Neowave), with several portable spin-offs, fourseparate continuities (Maximum Impact, EX, R, Days of Memories; each with a minimum of two games apiece), and various other titles like the RPG-styled KOF: Kyo and pachinko slot games. The King of Fighters XIII is currently the latest game.
The entire "Tales of Ash" saga is pretty much a Wham Arc (Rugal has children, Chizuru and Iori lose their powers, the seal on Orochi is broken, Ash beats Orochi Iori effortlessly, etc.), but this is all compounded by the death of Ash.
Where the Hell Is Springfield?: South Town. While its exact location in the US is never revealed in the games (same goes with the Fatal Fury and Art of Fighting series), it's heavily implied that it's located in Florida, and the city is inspired by Miami.