One of the first choices any writer has to make is how many characters will lead the narrative. Believe it or not, that number ''matters.'' Too many, and you can barely get attached to anyone, just one and [[PlotArmor you'll never believe]] the author [[LikeYouWouldReallyDoIt would kill them off]].

So, which is the lucky number for {{Ensembles}}?

Let's start at '''[[SolitaryTropes one]]''' and work our way up. A protagonist is not some embryonic proto-cast that contains the traits of all Ensembles past and present, but rather has complete freedom to be whoever is needed for the story. Let's repeat that: ''lone''. Though a one-man hero doesn't have to be an [[LonersAreFreaks antisocial loner]], they are very independent no matter [[CharactersAsDevice what kind of character]] they are. Even the wimpy ActionSurvivor is at least able to survive. Interestingly, the best lone heroes make up for a lack of permanent cast with a varied supporting (though temporary) cast and (hopefully) some internal struggles to add [[HiddenDepths depth]]. The Person vs Person type of dramatic struggle is common for the lone hero. Needless to say they are ''also'' invariably TheHero (well, let's say protagonist to hedge our bets). Though that's kind of a "Duh" statement, read on.
* ''Common genres or stories:'' These characters can be in any story and aren't weighed down by a large cast; they can realistically be WalkingTheEarth as TheDrifter. Even if sedentary, they'll likely play the lone ActionHero against overwhelming opposition. What you ''won't'' see is either drama with lots of long term character interaction or a stable, unchanging environment. These heroes will live and work in a fluctuating world.
** '''Signature series:''' ''Series/KungFu'', ''ComicBook/IncredibleHulk'', ''Franchise/{{Metroid}}'' (''[[VideoGame/MetroidPrime Prime]]'')

From there, the '''[[DuoTropes duos]]''' are [[{{Foil}} an even split between two traits]] in terms of body, mind, or temperament (usually all three). One is the brawn to the other's brains; [[RedOniBlueOni one is emotional and fiery while the other is more cold and analytical]]; [[BuddyCopShow one is by-the-book while the other feels rules should be flexible]]. The duo implies a certain level of equality: it's entirely possible for both to "share the billing" and be equal heroes. They'll likely be HeterosexualLifePartners, but if they happen to be different genders, it's practically a law there'll eventually be UnresolvedSexualTension (unless, of course, they are a BrotherSisterTeam, and even that doesn't stop some writers). If this sexual tension ''[[TheyDo is]]'' resolved, then you have a BattleCouple (cue the shipping). When the equality goes away, you have a different dynamic, TheHero and their SideKick or LoveInterest. These duos are different in that the hero often serves as a [[{{Mentors}} mentor]] to the sidekick or protector to the LoveInterest. It's unlikely for the sidekick to graduate from the role to a true equal.
* ''Common genres or stories:'' Again, any and all. However, duos gain a certain level of stability as compared to lone heroes. The character interaction between them will often become deep and nuanced to a degree not often seen with other ensemble numbers. Duos are likely to be in ActionAdventure shows, possibly playing Detective or [[TheyFightCrime fighting crime]].
** '''Signature series:''' ''Series/TheXFiles'', ''Series/{{Supernatural}}'', ''Series/HerculesTheLegendaryJourneys'', ''Series/DoctorWho'' (often), ''Literature/AubreyMaturin'', ''Franchise/SherlockHolmes'', ''Franchise/TheLoneRanger'', ''Series/MiamiVice'', ''Manga/FullmetalAlchemist''

When you get to '''{{Power Trio}}s''' the different splits get more interesting. The personalities divide into three, not so much dividing the [[RedOniBlueOni Red and Blue oni]] as creating a "balance" personality wholecloth. Note that any of them can be the lead hero. If the division is between physical and mental, it doesn't get degraded, but augmented with a [[TheHero balanced]] character, a character to mediate the previous pair. In personality and behavior terms, it may involve a scale of NiceMeanAndInBetween. If combat is involved, you get the MightyGlacier, JackOfAllStats, and a FragileSpeedster and/or GlassCannon. Interestingly, from Trio on down you start seeing the above archetypes merge into things like GeniusBruiser. They may or may not be a FreudianTrio of TheKirk, TheSpock, and TheMcCoy. It's worth noting that from here on out a girl being in the group [[TheSmurfettePrinciple gets logistically easier]] and [[ThreeAmigos much more]] [[BeautyBrainsAndBrawn common]].
* ''Common genres or stories:'' A trio is downright homey, and not in the sedentary sense. Three is the number where a family of friends can be born; characters can become TrueCompanions. Even if they don't see each other as a family, the dynamics between them will give viewers a sort of "safety net". Past this size, even when the group's adventures lead to them traveling the world (or galaxy), they will tend to work out of a base (or CoolShip) which often becomes something of a character in its own right. Trios work best in genres where there's room to interact both with each other and with the environment, from here on down an ensemble can hypothetically devote an entire episode or chapter just to the cast interacting. These guys are likely to be in an ActionAdventure or {{Drama}}. Or both!
** '''Signature series:''' ''Series/StarTrekTheOriginalSeries'', ''WesternAnimation/ThePowerPuffGirls'', ''Literature/HarryPotter'', ''Literature/ASeriesOfUnfortunateEvents''

The '''quartet''' is a challenge: just enough people for things to get convoluted, but not enough to lose track of anyone. The FourTemperamentEnsemble divides the [[RedOniBlueOni Red and Blue Oni]] in half again: the Red Oni splits into sanguine and choleric, and the Blue Oni into phlegmatic and melancholic. Alternatively, the characters can be split into a FourPhilosophyEnsemble in which the characters have different viewpoints and philosophies, rather than personalities, which interact as they face problems and have to reconcile their differences to come to agreement.
* ''Common genres or stories:'' Drama is the order of the day for the quartet, particularly internal drama. A quartet is likely to 'split up' in a given episode, giving each a chance to play off not just each other but dealing with the various aspects of the plot and the week's guest characters. Expect occasional reminders of why everyone is special and important, even if they're {{Muggles}}.
** '''Signature series:''' ''Franchise/TeenageMutantNinjaTurtles'', ''Series/BuffyTheVampireSlayer'', ''ComicBook/FantasticFour'', ''Series/StargateSG1'', ''Series/{{Seinfeld}}'', ''Series/{{Sliders}}''

'''Five''' and anything beyond that point tend to vary quite widely in makeup, as the personality and physical traits by this point can be pretty arbitrarily mixed and matched without worrying about maintaining a "[[CastSpeciation balance]]" in the cast. Typically, TheHero stops being a label and becomes a physically distinct character type that leads the ensemble's members. It's quite common for a group of five to consist of two trios (and an optional extra), often based on gender - these may or may not conform to the ThreeFacesOfAdam and the ThreeFacesOfEve.
* ''Common genres or stories:'' Though roving bands of extended casts are not unheard of, they ''will'' carry their home with them, be it a space ship, a [[Franchise/ScoobyDoo Mystery Machine]], or merely [[WalkingTheEarth the clothes on their back]]. These enormous ensembles practically write a Drama themselves, never mind having [[HilarityEnsues Hilarity Ensue]] due to outside events.
** '''Signature series:''' ''Series/PowerRangers'' (5), ''Series/HowIMetYourMother'' (5), ''Series/{{Friends}}'' (6), ''Series/SavedByTheBell'' (6 -- 7 if you count Mr. Belding), ''Series/StartrekTheNextGeneration'' and onward (7+), ''Film/SevenSamurai'' & ''[[Film/TheMagnificentSeven1960 The Magnificent Seven]]'' [[TropeNamer (7)]], ''ComicBook/JusticeLeague'' (usually 7), ''Anime/DigimonAdventure'' (7, [[SixthRanger later]] 8), ''Series/ArrestedDevelopment'' (9) and ''{{Series/Firefly}}'' (9)

Beyond five, there are no hard and fast rules for the cast as a whole. However, even with LoadsAndLoadsOfCharacters, the cast members can be broken down into a GeodesicCast or a set of {{Cast Herd}}s, each iteration of which usually follows one of the archetypes listed above. Individual characters may belong to a single group only, or they may belong to several, with their role sometimes changing depending on which group they're interacting with.

See also JustForFun/HowToGatherCharacters and PlayerCharacterCalculus for the video game counterpart.

This list primarily applies to gaming and action/adventure tales:

||align=center border=2 width=100%
|| '''''Cast Members''''' || ''Role'' || ''Emotional-Temperamental'' || ''Combat'' || ''Weapons '' ||
|| '''One''' || TheHero || TheDrifter, KnightErrant || OneManArmy || Any weapon available ||
|| '''Two''' || BrainsAndBrawn || RedOniBlueOni || BashBrothers, ForceAndFinesse || SwordAndSorcerer ||
|| '''Three''' || PowerTrio; FreudianTrio; [[SensitiveGuyAndManlyMan Sensitive Guy, Manly]] NobleMaleRoguishMale || [[TheKirk Kirk]], [[TheSpock Spock]], and [[TheMcCoy McCoy]]; NiceMeanAndInBetween || FighterMageThief; JackOfAllStats (TheHero), MightyGlacier ([[TheBigGuy Big Guy]]), FragileSpeedster ([[TheSmartGuy Smart Guy]]) || HeroesPreferSwords (TheHero), LuckilyMyShieldWillProtectMe ([[TheBigGuy Big Guy]]), and MagicWand ([[TheSmartGuy Smart Guy]]) ||
|| '''Four''' || "[[TheLeader Leadership]]" || FourTemperamentEnsemble || BalancePowerSkillGimmick || HeroesPreferSwords (TheHero) ||
|| '''Five''' || "[[TheHeart Spirit]]" || FiveManBand || SquishyWizard (TheChick) || SimpleStaff (TheChick) ||
|| '''Six''' || TheCutie, {{Nerd}}/{{Geek}}, or CloudCuckooLander or SixthRanger || Add TokenEvilTeammate || What varies from there and beyond are the types of [[WeaponTropes weapons]] and magic/skills, since every number past five will invariably get convoluted || The rules for Combat apply, probably with 10+ weapon types and no/loose rules for specific usage ||
|| '''Seven''' || || PluckyComicRelief, KidHero, or TheStoic || || ||
|| '''Lots''' || || || TheSquad || ||

See also:
* '''One:'''
** TheDrifter
* '''Two:'''
** RulingCouple
** SensitiveGuyAndManlyMan
** NobleMaleRoguishMale
** HeterosexualLifePartners
** BattleCouple
** AdventureDuo
** TheWatson
* '''Three:'''
** PowerTrio
** ComicTrio
** FreudianTrio
** NiceMeanAndInBetween
** [[SensitiveGuyAndManlyMan Sensitive Guy, Manly]] NobleMaleRoguishMale
** ThreeAmigos
** TwoGuysAndAGirl
** WithAFriendAndAStranger
* '''Four'''
** EliteFour
** FourPhilosophyEnsemble
** FourTemperamentEnsemble
** FourManBand
* '''Five:'''
** FiveManBand
** FourTemperamentEnsemble + Leukine
** FourPhilosophyEnsemble + The Conflicted
** PersonalityBloodTypes
* '''Six:'''
** FiveManBand plus SixthRanger
* '''Seven:''' TheMagnificentSevenSamurai
* '''Eight:''' PersonalityBloodTypes, can be four Rh+ and four Rh-
* '''''Lots:''''' LoadsAndLoadsOfCharacters
** CastHerd
** GeodesicCast

There's also a set of the above for all girl casts:
* '''Two'''
** LovelyAngels
** TomboyAndGirlyGirl
* '''Three'''
** BlondeBrunetteRedhead
** TheHecateSisters
** TheThreeFacesOfEve
** BeautyBrainsAndBrawn
* '''Four:''' FourGirlEnsemble
* '''More:''' AmazonBrigade

And we ''also'' have an evil version of some of the above:
* '''Two:''' EvilDuo
** ThoseTwoBadGuys
* '''Three:''' TerribleTrio
* '''Four:''' FourIsDeath
* '''Five:''' FiveBadBand
** ThePsychoRangers
* '''Six or Seven:''' FiveBadBand + EnigmaticMinion and/or MoralityPet