Cast Speciation

"We don't need two stretchy guys down there!"
John Stewart, Justice League Unlimited

A looser adaptation of the Five-Man Band. Generally speaking, it's bad form to have two major crew members on the show who essentially perform the same job (unless you have a multi-team Heroes Unlimited situation). That would lead to inevitable comparisons between the two, and probably lots of flame wars.

So any character who starts mirroring another too closely will have a different personality which affects the outcome of their work, or will be given a noticeably different job. One way to do this is to make the two rivals, competing to be the best at what they do. In this case, usually one is more friendly and laid-back and the other is more serious and stoic.

Does not apply to Evil Minions who sometimes come in faceless dozens, but does for, say, Battle Butlers or Dragons.

Occasionally, executive pressure or plain bad writing will force a character to not ever evolve past their original role, or instead force a new character into it. In the latter case, the original's days are numbered.

Can be avoided from the get-go by an Economy Cast or lampshaded by an Evasive Fight Thread Episode. This trope falls purely within the Rule of Drama. In real life, some degree of redundancy is generally considered a good thing, so that a group isn't crippled if one member with a specialized skill is taken out the picture.

Not So Similar is the super trope. Compare Divergent Character Evolution, which happens gradually and isn't as deliberate. See also Chickification, a common cause of which is this trope.


Anime & Manga
  • Sailor Moon's Minako Aino originally starred in her own manga, Codename: Sailor V, before being absorbed into the series, creating the odd situation where the derived character (Usagi) ended up being the lead. Minako has since undergone Divergent Character Evolution twice: a more outwardly capable but loopy character for the anime, and a straight serious character for the Live-Action Adaptation.
    • Pretty much all her incarnations treat her as a veteran, and occasionally showcase her greater experience at being a Magical Girl than the rest of the Senshi, and except in the anime. The manga and live-action show especially shows her being serious and knowledgeable; the anime suggests that not being alone has loosened her up from the more serious personality she had in earlier seasons, but shows her being able to pull magical girl stunts (like leaping onto second-floor balconies from the street outside the house) while in civilian form.
  • Pokémon tends to use this within the main characters' groups of Pokemon, despite the preponderance of Poor, Predictable Rock elsewhere in the series. Occasionally, though, Ash will have two different Pokemon with similar powers and movesets; these are usually distinguished by personality.
    • The series also had no other main characters with electric Pokemon until Dawn got a Pachirisu.
      • May and Jessie briefly owned a Wurmple each at the same time, though this was likely intentional, as it provided an opportunity to showcase its multiple evolutions.
      • And May eventually ended up getting both a Bulbasaur and a Squirtle—though unlike Ash's, hers eventually evolved.
    • Dawn captured an annoyingly powerful Buizel, despite already having the water type Piplup and not even being a battler, while Ash didn't have any on his team. Cue rumors that she would eventually trade it to him.
  • Usopp in One Piece was the crew's general inventor and mechanic up until the introduction and joining of Franky, a shipwright who rebuilt himself as a cyborg. This was largely resolved (after Sogeking joined the crew) by emphasizing Usopp's role as a sharpshooter and also by having him focus on personal tools and inventions where Franky is more heavy duty with arming the ship and keeping it in condition. They're also drastically different in personality, Usopp being a Lovable Coward while Franky is more Hot-Blooded.
    • This is also built into the setting. Two people can't have the same Devil Fruit power at the same time - the fruit won't regrow until the last person who ate it dies.
  • Happened a lot in Naruto. Even though for the exception of Elemental Powers and inherited bloodline techniques anyone can learn anything, each character has between 1-5 special moves that no one outside of their clan or direct Master-Apprentice Chain is ever seen using. The biggest example is how at the Ninja Academy, all graduates are required to learn illusory clones and shapeshifting jutsu, but only a handful of ninjas are ever shown using either jutsu even though they all should know both of them.
    • The Sharingan gives the user the ability to learn any jutsu after seing it oncenote  and Kakashi has a reputation of having learned over a thousand jutsus. However, the Sharingan users who appear on screen including Kakashi almost always just use the unique jutsus available exclusively to the Sharingan and almost never use any copied jutsus.
    • The most notable example is Sakura/Ino. Both had similar personalities (if anything, Ino was a more extreme version of Sakura), but by being each other's rivals, they became characters in their own respective rights. Character development further separated them. And while Ino has her clan's mind control jutsus, Sakura ends up learning Tsunade's strength enhancement and rapid healing techniques.
    • Naruto and Kiba also get this treatment; they have similar personalities (again, Kiba is described as being "even wilder than Naruto" by way of introduction), but have very different power sets in order to differentiate between the two. Later on, they become more separated.
  • Completely Averted in Dragon Ball. Every character has the same powers, with only one or two special moves differentiating them. But by the end of the series, everyone has either taught each other their unique moves, or developed something that essentially does the same thing. Whoever has the highest Power Level is the best in speed, power, endurance and Ki attacks.
    • In short, besides color and hand motions, there's virtually no difference between a Kamehameha, Gallick Gun, Final Flash, or Masenko. The damage they inflict has little to do with the technique itself, instead it's all about how much Ki the user can pour into it.
    • The only exception to this rule was when USSJ Trunks was stated to be more powerful than Perfect Cell but too slow to hit him.

Comic Books
  • As noted above, there's been a running gag in The DCU over the years about the Justice League's two "stretchy guys," Plastic Man and Ralph "Elongated Man" Dibny, who have the same powers and similarly light-hearted personalities. (The Elongated Man was created as a Captain Ersatz of Plastic Man, whose creator was unaware that DC had acquired the rights to Plas) DC separated the characters by emphasizing that Elongated Man was also a brilliant detective, and exaggerating Plastic Man's fun-loving side to the point of outright lunacy (at one point Plas says about Ralph, "Nice guy, but someone left the door open and his personality just bolted"). DC seemed to be doing away with the confusion by making Ralph darker and moodier, arguably to the character's detriment, before concluding this character arc by having him die in a Heroic Sacrifice. And more recently, Ralph and his wife have returned as crime-fighting ghosts. Which is ... quite different indeed.
    • The JLA used the rule of "no two people can have the same power" to keep Hawkgirl/Hawkwoman out of the League for over a decade. Her husband eventually put his foot down about it. Of course, under that rule (as Scott Tipton once put it), the entire League should consist of Superman, Green Lantern, the Atom, Wonder Woman (only for the whip of truth) and possibly Batman (the Atom's already pretty damn smart, but not in the same way).
      • Diana has an unbreakable lasso, which in some versions can be used to compel truth-telling; a bit more than a "whip of truth." (There are also versions in which she is highly fire-resistant, is possibly immortal, has access to perfect regeneration technology, can travel to realms of myth and story, and/or can communicate with birds.)
    • The whole Plastic Man/Elongated Man thing is lampshaded in Batman: The Brave and the Bold, where the two are fighting baddies together while arguing which one of them Batman likes more. In the end, Batman shows up and says that he doesn't really like either of them.
    • Thing is, EM/Plastic Man don't have the same abilities. Elongated Man is a "stretchy guy who happens to be a genius detective-type". Plastic Man basically IS plastic, and can control/reshape every molecule in his body. Plus being nigh-invulnerable and seemingly immortal (3000ish years old and still going strong). Of course, this is deliberate Divergent Character Evolution specifically created in The Dark Knight Strikes Again.
  • Back during the Silver Age, Superman and the Flash were equally fast. Modern comics have made the Flash much faster than Superman to balance out Superman having a lots of other superpowers besides just running fast.
    Flash: Those races were for charity, Clark.
  • Legion of Super Heroes used to have an explicit rule that every member had to have an unique power; they've loosened up on this, although they still mostly abide by it in practice. (It's a particularly artificial limitation in the Legion's case, as many of their members have powers shared by everyone on their planet.)
    • And Karate Kid, who doesn't even have any powers of his own. When the Legion was going to veto on him, he showed them that while he doesn't have any super powers, he can literally kick ass in about a thousand different ways. The Legion then decided to change their minds and induct him. Fans have since joked that his power is being able to make Superboy tap out.
      • Of course, once you actually join the Legion, the first thing they give you is a flight ring - so apparently there is one power it's okay for everyone to have.
  • In the X-Men verse, it has become formulaic for every team to have a telepath, powerhouse, energy blaster, and/or one member who won the Superpower Lottery.
  • In the Fantastic Four both Reed Richards (Mr. Fantastic) and Ben Grimm (The Thing) are highly intelligent and honored scholars and scientists, but everyone likes to focus on Ben's physical strength rather than his brain and the result is that the Thing very often comes off as Book Dumb.
    • Most of the time when Reed is going off on his Sesquipedalian Loquaciousness (usually explaining whatever Deus ex Machina he's cooked up) The Thing's problem isn't with what he's saying not making sense, but simply taking too long to say it when there are more important things to be done. This leads to him losing his patience and yelling "THE POINT, STRETCHO! GET TO THE POINT!"
    • Not to mention the fact that Ben is often seen dumbing down what Reed says for other people.

  • Done in the X-Men movies (the comics... not so much). According to the features, some characters were never used for precisely this reason. At least before the character flood in X-Men: The Last Stand.
  • Curiously averted in The Avengers: Tony Stark describes said team to Loki as "your brother the demi-god; a super soldier, a living legend who kind of lives up to the legend; a man with breath-taking anger management issues [and] a couple of master assassins" (Black Widow and Hawkeye). In the comics, Hawkeye is slightly more 'wacky' and wisecracking, but with Iron Man having taken over as the movieverse's brash rascal, Hawkeye has lost that quality, putting him in the same category as "dour government hitman" Black Widow. To compensate, Hawkeye is more of a quiet sniper type, although once he's out of Loki's mind control, he's making casual jokes.

  • Downplayed in the Drizzt Do'Urden novels. Of the five main characters (six counting the mascot), four are skilled melee fighters. It's broken up by having one of them being far and away the best technical fighter; one of them being monstrously strong; another being a tough, tactical group-fighter; and the fourth usually doing ranged support. Later, one leaves, and another shows an interest in magic, while a third gets older and starts attending as much to his political duties as his military ones.
  • The Weasley twins of Harry Potter are wisecracking pranksters with Twin Banter, but Fred is a bit crueler and George is a bit more sensitive.
  • In the introduction to Speaker for the Dead, Orson Scott Card discusses how he accomplished this:
    My immediate task was to differentiate clearly between Novinha's children when the reader first encounters them. I sat there in the room I shared with Gregg, assigning some immediate and obvious trait to each of the children that would help the reader keep track of them. Oh, yes, Olhado is the one with the metal eyes; Quara is the one who says outrageous things after long silences; Grego is the violent one; Quim is the religious fanatic; Ela is the weary mother-figure; Miro is the eldest son, the hero in the others' eyes. These "hooks" could only serve to introduce the children—I'd have to develop them far beyond that point—but having found those hooks, I had a plan that would let me proceed with confidence.

Live-Action TV
  • The last season of Angel put a second ensouled vampire champion on the same show; they went the rivals direction with it and gave Angel, who previously thought of himself as unique, a bit of an identity crisis.
    • Of course, Angel and Spike have had a sort of rivalry since Season 2 of Buffy the Vampire Slayer, in which they vied for fellow vampire Drusilla's affections.
      • Heck, the flashbacks in various episodes show that they've been that more or less since Spike got turned.
  • In Buffy the Vampire Slayer, the split between Buffy and Faith can fit this trope.
    • Same with Kendra and Buffy, with Kendra being a very by-the-books Slayer and using more gymnastics in her fighting style. Also between any two Watchers.
    • While Giles is made fun of because of his British Stuffiness, he's a lot more laid back compared to Wesley (at least before his character development), as well as having a dark past. Gwendolyn Post, a rogue Watcher, is also seen as incredibly stuffy even compared to Giles and Wesley.
      Ms. Post: The council feels you've become a bit too. . . American.
      Giles: Me?
      Buffy: Him?!
    • Willow and Tara, both witches in the Scooby Gang, were set apart by their usage of magic. As Willow grew in power as a witch, she used her powers more often, whereas Tara would only use her magic for support or in dire situations. Willow also had the benefit of being a skilled computer hacker, but she used those skills less as the show went on.
  • Heroes does a lot of this, and follows the trope by making the pair have very different personalities. Peter good, Sylar evil. Claire good, Adam evil. HRG good[ish], Bob evil. Matt good, his father evil. Oddly enough though, Nathan and West are very similar people, the only differences being their ages, Nathan does his domineering sneakily whereas West does it to Claire's face, and West isn't meant to be seen as domineering.
  • Lampshaded in the 4th-season Desperate Housewives episode "In Buddy's Eyes":
    Bree: (to Katherine) Here's the thing you need to understand about me and my friends. We each have our niche. Gabrielle's the glamorous one, Susan's the adorable one, Lynette's smart, Edie's ... Edie, and I'm the domestic one, the organizer, the one who knows that there are three tines on a dessert fork, and the one who gets teased for that. That's who I am. And that's also who you are.
  • Lost: Two characters can contact the dead, but comparisons are avoided by the fact that one is a Deadpan Snarker while the other is...Hurley. Also brought up in the plot, as Hurley compares his powers to Miles'.
    • Their powers are also substantially different — Hurley often finds dead people walking up to him and striking up conversations, whereas Miles can hear a dead person's last thoughts if he's near the body.
  • Doctor Who runs into this problem whenever scientific companions are created:
    • The show gave this as reason for writing out Liz Shaw, a Science Hero companion who was almost as clever as the Doctor and who he treated like an equal. The argument was that she was necessarily not as good at science as the Doctor (seeing as he was an alien Impossible Genius) but also too strong and intelligent to have her catching the Distress Ball without it eroding her personality, meaning her gimmick was that she could do everything the Doctor could but not quite as well. The team replaced her with an ankle-twisting Dumb Blonde who was a more physical heroine than Liz was and tended to get more good scenes of sneaking around, doing 'escapology' and breaking vases over people's heads (and fewer good scenes of her doing chemistry and outwitting enemies, naturally).
    • Later (and earlier) companions who had being scientific geniuses as their hat tended to be contrasted to the Doctor by terms of having a major personality quirk that modifies how they use their knowledge - Susan was fearful and childish unlike the reckless and grandpaternalistic Doctor; Vicki tended to be foolhardy and emotional; Zoe was naive and while she was more knowledgeable than the Doctor she wasn't as good as him at applying the knowledge. K-9 is a Literal-Minded Robot Dog with none of the Doctor's social skills, wit or planning ability; Romana is convinced of her own superiority to everyone else and has no experience of life outside of her privilege; Adric is impulsive, ineffectual and gullible; Nyssa is sheltered; Turlough is devious; Ace was undereducated at everything except explosive chemistry and River is a mysterious Action Girl.
    • In the Classic series where companions were subbed in and out spontaneously depending on real life circumstances, you would occasionally run into companions encroaching on each other's plot territory:
      • Ben and Polly are a complimentary young handsome Action Hero/young beautiful insightful heroine pair, and the spontaneous addition of Jamie (another young handsome Action Hero) watered down the dynamic a tad. Most of the scripts while Ben and Jamie share companionship focus on Jamie's Scottishness and relative youth to differentiate them, but the writers clearly were struggling to use them both. "The Macra Terror" goes so far as to use them as rivals, a dynamic that probably would have continued had Ben and Polly stayed longer.
      • Harry Sullivan was added to compliment Sarah Jane by being an Action Hero as they were going to swap out the Doctor from an experienced martial artist to a distant and calculating character played by an elderly actor. When some fool decided instead to cast a 6'4 former brickie younger than any Doctor cast thus far, Harry was (by the admission of the producers) left with nothing to do. The answer was to give the action scenes to the Doctor, capitalise mostly on Harry's medical background and slight stupidity, and give Sarah Jane the Distress Ball.
      • K-9 was added to justify the expense in building a robot dog prop for a small role in a one-shot story. This was generally awkward as his main gimmicks (Super Senses, being Literal-Minded, carrying a weapon) were shared by Leela, and his others (maths and science knowledge, computer literacy, superior resilience, alien perspective) were shared with the Doctor. It is not uncommon, even after Leela's substitution with Romana, for K-9 to be left out of stories due to having nothing to do that the other characters can't do better.
      • Adric was intended to serve as a counterpoint to the Fourth Doctor, who by that point had developed into an imposing, hyper-competent, quasi-mystical force of nature, and so he was made emotionally impulsive and vulnerable to ground the Doctor somewhat. When Nyssa, an alien scientist, was added, his super-genius skills became redundant (especially since Nyssa was good at other things than just maths) and when the Doctor regenerated into the more vulnerable and flawed Fifth Doctor his flawed-hero side became redundant as well. Again, this led to him being left out of plots due to having nothing to do.
    • This was a major problem for the Daleks and the Cybermen - keeping the two Always Chaotic Evil Cyborg monsters clearly delineated has been hard work for most eras. The Cybermen are interested in assimilation and the Daleks in genocide? Fine, except the Daleks assimilate humans in "Revelation of the Daleks" and the new series, and early Cybermen are quite into genocide. The Daleks are emotional beings while the Cybermen are completely emotionless? Except the Daleks' lack of emotion is central to "Destiny of the Daleks" and the new series explicitly says they have every emotion removed except hate, while Cybermen become extremely emotional (bordering on Large Ham) in the 1980s to the point where the explanation was that they have every emotion removed except rage. You can defeat Cybermen with The Power of Love while Daleks laugh in the face of it? Daleks get defeated with love too, in "Evil of the Daleks" and "Victory of the Daleks". Cybermen can masquerade as humans while Daleks pretend to be good? Daleks have made humans into Dalek agents, or humanoid Dalek robots, in both the Moffat era and the Verity Lambert era, and Cybermen have pretended to be good in stories like "Army of Ghosts" and "Dark Water". Ultimately, there have been enough Cybermen stories using Daleks and enough Dalek stories using Cybermen that, taken as a whole, the two races are mostly aesthetically different. Each era has its own idea of how to differentiate them, and each of those eras is contradicted in some other one.

  • From the Book Of Revelations, the Four Horsemen were Conquest, War, Famine and Death, in that word. None were explicitly named, however, except Death. In part because Conquest and War overlapped, but also because of the Black Plague, Conquest was replaced with Pestilence.

Tabletop Games
  • Traditional parties of player characters in any tabletop RPG will tend to have three to five people filling specialized roles going on adventures; this tends to overlap with An Adventurer Is You with everyone being a different class.
  • The gameplay Hat of the Eldar army list in Warhammer 40k, and to a lesser extent the High Elves in Warhammer. Each unit will have a specific situation or a specific foe they are very good at dealing with, winning relies on getting very varied elements of the army working together perfectly to handle any foe.
  • Monster of the Week, a game about monster hunting in the vein of Buffy or Supernatural using the basic Apocalypse World engine, explicitly enforces this: by the rules, each player has to pick a different Hunter archetype, so there can be at most one e.g. Chosen, Expert, Professional, or Wronged, bringing not only their own specialized moves but also built-in different perspectives to the hunt. (This does have the practical benefit of making it easier to print out a full set of archetype-specific "playbooks" — basically pre-customized character sheets — because one copy of each should be sufficient.)


Video Games
  • Some players of the superhero MMORPG City of Heroes may avoid having more than one person on the team with the same powers or even the same class to avoid redundancy, especially as a team can only have up to eight members. On the other hand, there are cases when such redundancy may be desired if the superpowers have effects that can easily be stacked on a foe, such as with status effects when used against highly resistant foes.
  • In other MMOs, this is where hybrid classes truly shine, especially in World of Warcraft where players can now take two specializations. For example, if an offensive-casting or melee Druid joins a party that already has strong DPS, she can be the healer or Tank instead, depending on what's needed more.
  • In Mega Man 9, Mega Man lost his slide and charged shots so that he could play more like he did in the first two games. His lost abilities were instead given to Proto Man, who has the additional ability to block enemy fire while jumping. These differences were retained for the next game, which also included Bass, who can dash and has no Denial of Diagonal Attack. Mega Man, however, does have an advantage over them by being the only character capable of using the Bonus Bosses' weapons.
  • Slightly different, but fits here: The original Fire Emblem featured multiple Palette Swap Player Character units, including the identical-portrait Saji and Maji (Bord and Cord in English). Remakes of that game and sequels with the same cast thankfully changed all of that (Bord and Cord have different tunic styles and are looking different directions now).
    • The sixth, seventh and tenth games do this with their Dancer-style party members. They all serve the same gameplay function, to give an ally an extra turn, and for obvious reasons only one can be on the battlefield at a time. In the sixth, you have Elphin the quiet, reserved Bard who turns out to be the prince of Etruria in hiding and Lalum the cheerful flirty dancer, who are Mutually Exclusive Party Members. In the seventh, the similarities bewtween Nils and Ninian are justified by them being siblings, but Nils is a bard who uses Magic Music while Ninian is a softspoken Dancer. The tenth game, Radiant Dawn, has three Herons, and this time the differences make their way into the gameplay: Raphael's chants always refresh 4 allies, the tradeoff being that he moves slowly and can't fly, Leanne can refresh two allies at once (either left and right or up and down), while Reyson can only refresh one ally normally but 4 while transformed.
  • Touhou has always featured Reimu, a shrine maiden, who is tasked with hunting youkai and preventing them from causing trouble. Terminally selfish and lazy, Reimu sees these duties as an annoying chore, and puts little effort into her training, instead relying entirely on her ridiculously powerful talents and family tools (and she originally hadn't even bothered to learn how to use either of those). Further, she's a staunch Nay-Theist; as a shrine maiden, she should be establishing good relations with the gods so that they'll loan her their power, should be encouraging the people's faith in the gods so they have more power to give her... but Reimu simply can't be bothered, no matter how many youkai mock her about it. Reimu outright believes that effort is not rewarded.
    • SO, when a second miko was introduced to the setting, she was almost completely different. Sanae is dearly devoted to (and very friendly with) the two Physical Gods of her shrine and glad to work for them, whether in personal service, promoting faith among the people, or hunting youkai. Sanae was born with incredible power like Reimu, but instead of random human talent, her talents are divine in origin, as one of her goddesses is also her ancestor (though Sanae was left in the dark about this until a later game); her own diligence in training her powers actually earned her the status of "deified human" from people praying to her as well as her goddesses. Finally, Sanae was born and raised in the normal, modern world outside of Gensokyo, and so brings a very different perspective to the crazy inhabitants and events of that land.
  • Zelos Wilder and Kratos Aurion in Tales of Symphonia have nearly indistinguishable battle skills, but the former is a laid-back and good-humored Classical Anti-Hero while the latter is a prudent and easily frustrated Nineties Anti-Hero. They're also mutually exclusive to use at the end of the game.

Web Comics
  • In Homestuck, your Title is determined by a Class and Aspect. In a SBURBan session, no two players will ever share a Class or an Aspect in order to guarantee variation in what the players are capable of.
  • In Eight Bit Theater, Drizz'l was originally characterized as being The Ditz on par with Fighter. Not long after, he joined the Dark Warriors, who already had a comedy moron character in Bikke. As a result, he became the Only Sane Man.

Western Animation
  • The Land Before Time has built up a number of secondary characters over the sequels, one of the most popular being Ali, a girl who is the same species of dinosaur as Littlefoot. However, despite her popularity, she has not shown up more than twice and when a guest character was elevated to main character for the TV show, Chomper was picked instead. Admittedly he was popular in his own right, but the likelihood that the writers did not want two characters of the same species in the main group was probably a factor.
  • Unfortunately averted in the old Superfriends series, as Seanbaby notes. Hawkman and Hawkgirl could fly, but so could most of the other heroes on the show (even Flash when the animators were forgetful).
    "If you're a Super Friend, being able to fly is like being able to break a graham cracker along the line... All the Super Friends who can't fly can just hop in a little supercar or something invisible that flies... Regular people can't fly, but they can kick Hawkman's pigeon ass as soon as he lands."
    • Played straight as well, with Aquaman, and with just as unfortunate results. While Aquaman is strongest around open water he still has super strength and resilience out of water. Apparently worried that he would make Superman obsolete (yeah, right) the writers downplayed his non-aquatic powers to the point that he became basically helpless. Spending most of his time as a male version of the Damsel In Distress quickly dropped him to Scrappy status.
  • Batman: The Brave and the Bold has both Plastic Man and Elongated Man, who are rivals and accuse each other of being the other's Poor Man's Substitute who Batman only asks for help when the other is busy. Plastic Man even refers to Elongated Man as his "D-list doppelganger".