Economy Cast

""The Cybermen are coming! All three of them!""

- Gag line by Ian Marter (Harry Sullivan in Doctor Who)

When any necessary role in a series is essentially represented by only a single person, even if it would be more realistic to have several. Instead of coming across a dozen different police officers depending on the nature of the crime and who's on duty that day, our heroes always deal with the same lieutenant. Or there's one doctor who treats every injury, from broken legs to melanoma. Or why a starship captain and the main bridge crew are always the ones going on away missions. This is mostly a way to avoid having to keep track of too many characters.

In adaptations, this often results from the creation of a Composite Character or characters to stand in for an entire group from the original work. Writers generally have to build up a back-story so the audience can care about a character, which has little payoff if we don't see much of them anyway. It is much easier from a director's standpoint to wrap one character in several incidental roles or just one overarching 'figurehead' role.

Economy Casts are contributing factors in Unwanted Harems too, as the pretty girls invariably focus on the Loser Protagonist, for lack of any other option. Any time the story calls for a male to do something, it’s him — so he ends up as the only male character the girls get a chance to pay attention to on-camera.

One danger of this is the marketing and executive branch of creating stories installs the Status Quo on the Economy Cast, and characters aren't allowed to develop too far out of their roles.

See Ghost Extras for when the non-core cast is on-screen but living in a separate universe. See also Two-Teacher School or Omnidisciplinary Scientist. A true story or adaptation may try to whittle down the cast by combining characters.

Take this trope to its logical extreme and you get a Minimalist Cast. For obvious reasons, it’s rare to find this co-existing with Loads and Loads of Characters.

The trope is not about a character who fills more than one narrative role. An Economy Cast defies real-world logic, not just storytelling guidelines. Nor is this many characters that look the same.

Anime and Manga

 * Used but also parodied on Lucky Star, where many of the minor background characters are played by a tiny ensemble of, more or less, Animated Actors (although the fourth wall is not outright broken until the closing "Lucky Channel" segment).

Film

 * Movies Based on a True Story tend to lump together a number of people who all had a role in the story into one or two "composite characters" for Conservation of Detail reasons: ten people who each had a minor role in the story, or six different detectives looking at a case over several years, would be more confusing in a 90-minute story than one character representing them all.
 * Most war movies tend to invoke this trope, largely because it makes it easier for audiences to care about one character or a small group as opposed to an entire Division (which could consist anywhere from 10,000-20,000 soldiers) of them.
 * As an example, during Saving Private Ryan, in the D-Day landing at Omaha Beach, many brave soldiers fought and died. The main characters mention them by name, but the focus is on Captain Miller as well as the other characters who would later go on the next mission that takes up the rest of the film. The other men, such as the 82nd and 101st Airborne soldiers the main cast runs into during their mission were heroes in their own right.
 * Zombie Apocalypse films tend to do this as well. It's easier to identify with a small group of survivors rather than a large group who may not get much screentime.

Literature

 * This sometimes happens in historical novels, particularly when they occur in eras (most noticeably Tudor times) where every other person was named after the current King and Queen. To have an accurate number of characters with those names would be plain confusing.
 * And in Based on a True Story it can be to big up someone's part in events even if they weren't there. The film Cromwell is perhaps the most infamous example. Quite perplexingly so given the actual truth has him as extremely important in any number of events, but they felt the need to insert him into other events all the same.
 * Appears in the Hunger Games books where bit characters are more likely to perform newly required tasks rather than new character being introduced, even when it would be far more likely in real life for there to be more people involved. Furthermore, previous bit characters have a tendency to somehow reappear simply because it is easier than to write a new character in (e.g. the prep team).
 * Mystery novels set in times or locales where it'd be normal to have loads of servants about the place will very often take place on the servants' day off, to spare the writer from having to account for a bunch of extraneous potential suspects.

Live Action TV

 * On NCIS, whenever they have a case that goes into FBI territory it is always something Gibbs' best friend Senior Special Agent Tobias Formal has been working on for years, no matter what area the investigation is looking into (organized crime, homeland security, catching serial killers, smuggling, etc.). This has been Lampshaded a few times, once they showed his office was overflowing with paperwork and he complained the weight of the world was on his shoulders. Another time they showed Tony Ziva and McGee going through his case load and commenting on how diverse it was.
 * This is prevalent in House, where the three fellows and House perform every test and procedure, even those that only specialists would perform (at one point House assists in brain surgery). There is some Lampshade Hanging on this, as Dr. House makes it clear that he thinks that if you didn't do it, you can't trust the results.
 * Also, doctors would rather risk their careers by breaking and entering than hire someone else.
 * And they dig up a patient's dead dog once. You'd think they have lackies to do these things. Even if they are House's lackies.
 * Not to mention, the hospital appears to employ maybe three nurses tops and zero technicians.
 * Perry Mason spent 141 episodes humiliating DA Hamilton Burger and police Lt. Tragg. It stands out all the more because Mason operated in the sprawling Los Angeles metro area and theoretically could have faced a different team of detectives on each case and literally dozens of DAs and ADAs at trial.
 * Although there were a few episodes where he did face someone else during that run...but he was specifically in another city or town.
 * What’s more, in the novels, Perry would use out a different investigator from the Paul Drake Detective Agency each book. In the TV series, Paul Drake would do all the investigation.
 * We see the detectives in the Law and Order franchise dealing with the same prosecutors, and vice versa, not to mention the same coroners and psychologists. Law and Order Special Victims Unit is probably the worst. In real special victims squads, the cops are frequently rotated out specifically because it's so psychologically damaging, but the show has the same two detectives there for over a decade.
 * The morgue in Pushing Daisies seems to have only one coroner, although the pilot seems to indicate that though Ned had been working as consultant to a Private Detective for a while, that coroner had never met him before, so perhaps there is/was another one.
 * According to the Word of God there are other people working there but that coroner is the only one who lets them in no questions asked because he has a crush on Emerson.
 * The police characters in Third Watch would always meet the same paramedics and/or firefighters at the rescue scene.
 * Slightly justified in that they were all on the same block and worked the same shift. There were also a lot of extras in each group, without due attention necessarily being given to them. (Though to be fair, except for Jimmy and Alex, the whole FDNY was treated as an "extra").
 * A mild version on The West Wing: after six years of showing events in the White House, the show had to address the campaign for a successor. Promptly, three regular characters quit for jobs in the primary election campaigns... and another got to organize the nomination convention... and later ran for Vice President.
 * Stargate SG 1, to this troper is the epitome of Economy Casting. As another troper pointed out on the Mildly Military page, having a Colonel lead a team with just four people is really unusual, in Real Life Colonel's typically command much larger companies. Also, the kinds of things that the team tends to handle would typically involve a whole platoon in other cases.
 * It's not that strange based on the "official" mission profile of SG-1 being special forces recon. Most of the antagonists are not secretive, so sending a larger force to cover more ground in unnecessary.
 * Police Squad! featured Johnny The Shoe Shine Boy, who was Frank Drebin's informant in every single episode, no matter who or what he needed information about. To send things into pure parody, he was also an informant for numerous characters in random professions.
 * Early episodes of Mash had a larger number of surgeons, including Spearchucker and several other one-time or background characters. Later, however, Hawkeye, Trapper, Henry and Frank (or Hawkeye, BJ, Potter and Charles after the cast changed) are the only resident surgeons seen in the entire 4077th.
 * As the page quote suggests, this often happened with enemy races on the original series of Doctor Who. It was most painfully obvious with the Daleks, because by the time the show hit the 1970s the producers only had three very beat-up Dalek casings on hand and no money to build more. (The 1972 story "Day of the Daleks", for example, could not hide the fact that the attacking band of Daleks from the future consisted of exactly three Daleks.) Some stories, going back to the very first Dalek adventure "The Daleks", featured (very unconvincing) photo blow-ups of Daleks for background shots. Of course, with the advent of CGI, the new series expends some effort in the opposite direction, showing thousands and thousands of Daleks in one shot at the end of "Bad Wolf" (2005), though the Daleks were reintroduced earlier in the season with a single Dalek (in "Dalek").
 * The SAMCRO chapter of the Sons of Anarchy consists of only eight members and a 'prospect'. This is small compared to the various other gangs they are allied or in conflict with including the other chapters of the motorcycle club. Also one of the members is mostly retired and sick enough to carry an oxygen tank with him. They are all extremely Badass but if 2-3 of them are put out of commission, the gang becomes extremely vulnerable and they have to pull in people from other chapters to survive.
 * Star Trek is a particularly egregious offender. DS9 in particular stands out because the main cast is supposed to be running a war. In one episode, they're all - *all* - on a risky recon mission in the middle of nowhere.
 * Slightly justified on The X-Files. Nobody cares about the X-Files and it's outside the FBI mainstream, so there aren't a lot of agents assigned to it. And they don't usually solve cases outside their department. They also interact with other FBI agents assigned to other cases, though those are usually one-episode characters.
 * The rebel slaves in Spartacus use this to their advantage. No matter how many men the Roman have, they can only attack with as many as can fit on a small set at one time.

Music

 * This is one of the reasons why it's so rare to see live bands with more than six performers - even if they have a whole symphony orchestra and an army of guest stars playing on their album.

Theater

 * Lampshaded in Shakespeare's Henry V, in which the Chorus asks us to "piece out our imperfections with your thoughts / Into a thousand parts divide one man ... Think when we talk of horses that you see them...." Read it here.
 * A Very Potter Musical parodies the Potter books’ tendency toward this; no House in Hogwarts has more than five students and Hogwarts is a Two-Teacher School. Like most things in the musical, this is lampshaded
 * Hermione: "Snape picked from out of hundreds if not five Gryffindors."
 * They do actually refer to other teachers besides Snape, Dumbledore, and Quirrell, but they're never seen by the audience.

Various

 * Incorporated into most long-running mystery/crime series not involving an actual police detective. Since it is inevitable that the police will turn up to investigate crimes, and that they will have information the sleuth needs, the sleuth gets a cop "buddy", if he is friendly with the force (Detective Dennis Becker on The Rockford Files), or a cop stooge, if he is as arrogant as Sherlock Holmes (Inspector Lestrade).

Video Games

 * Phoenix Wright: Ace Attorney takes this to an extreme; except for one-shot characters who turn up in single cases as suspects or victims, it has only one detective, Detective Gumshoe, who is the detective in virtually every case, as well as one judge (except in situations where a second judge is absolutely necessary, when his almost identical brother is introduced.) The game engages in frequent lampshade hanging over this, with Gumshoe often expressing disbelief at how often he ends up investigating a murder where Phoenix is involved.
 * And when Gumshoe finally gets a break after Phoenix stops being a lawyer for Apollo Justice, Ace Attorney? Ema Skye, a former one-shot character who replaced Maya Fey as Phoenix's sidekick in a past case, pretty much takes up Gumshoe's exact position, except relating to Apollo Justice instead. It takes her much less time to lampshade hang on this phenomona. (At least she manages to avoid being the victim of a pay cut during every case.)
 * Characters occasionally refer to contemporaries-Gumshoe to other detectives, Edgeworth to a superior organization of prosecutors, and Maya to other residents of Kurain Village all come to mind-but the cast we actually see and interact with is the Economy Cast we know and love. Strangely, in the fourth case of the second game, while in the police station Phoenix comments on the little Blue Badger statue and the police chief says the character was his idea, but we don't actually get to see a sprite of the police chief-possibly because this single line of dialog is the only time we encounter the chief in the entire game.
 * However, players can receive a different observation of the police chief every in-game day they can go to the precinct and "click" on the chief, and sometimes the results change during the day. Constant investigation will reveal the police chief spends a lot of time browsing the Internet and reading tabloids.
 * It goes even further than that. Click on the chief in any case of any game where you go to the department, and he's pretty much guaranteed to be saying something or doing something different. And you can get similar dialogue from the one detective who is always at his desk, usually either not doing his job or trying to write up a crime prevention slogan. They are, however, the only two members of the police you ever see in the precinct. Other than Detective Gumshoe, that is.
 * Phoenix, in his just over 3 year career, had all his cases run by the same detective and faced 6 prosecutors, all under the same judge. At least two of the prosecutors arranged to take charge of the trials Phoenix was running though.
 * Larry Butz and Wendy Oldbag show up all the time, seemingly just to save the time designing and introducing a new character.
 * In many games involving wars, you'd be surprised at how small your "Army" is. See Arbitrary Headcount Limit.

Web Comics

 * Starslip is set in a huge space museum / old war ship. There are occasional references to other crew members, but we only really see about 5 of them, despite the huge numbers that would be needed to run such a ship.
 * In Twokinds, Mike and Evals represent the whole crew of their ship.

Western Animation

 * A small aversion happens in Rugrats when Angelica is sent to the hospital, and an X-ray technician is shown operating the machinery.