Filming "back-to-back" is the practice of filming two or more movies as one production, reducing costs and time.
Trilogies are common in the film industry, particularly in science fiction, fantasy, action, horror, thriller, and adventure genres. Production companies may choose, if the first film is a financial success, to green-light a second and a third film at the same time and film them back-to-back. In a case where a lengthy novel is split into multiple installments for its film adaptation, those installments will usually be filmed back-to-back.
In modern filmmaking, employment is now project-based, transitory, and "based on a film[,] not a firm." Almost all participants in the industry are freelancers, who move easily from one project to the next and do not have much loyalty to any particular studio, as long as they get paid.
This differs from the old studio system, a form of mass production in which a studio owned all the means of production (that is, reusable physical assets like sound stages, costumes, sets, and props) and carried large numbers of cast and crew on its payroll under long-term contracts. Under the old system, "a producer had a commitment to make six to eight films per year with a fairly identifiable staff." Under the new system which replaced it after 1955, filmmaking became a "short-term film-by-film arrangement" in which a producer is expected to assemble an entirely new cast and crew for each project, and rent the means of production from contractors only as needed. To borrow a factory analogy, studios transitioned from using a single assembly line with an integrated staff to continuously churn out one film after another to building and disassembling separate assembly lines (each with its own unique staff) for every single film.
The advantage of the current system is that film studios no longer have to bother either with paying people who are not involved in a current film production, or with green-lighting films very frequently so as to efficiently exploit sunk costs in their human resources. Studios shifted from a emphasis on "speed in production" to "more cooperative pre-shooting planning." But now, when they want a particular person for a film, that person may be unavailable because they are already committed to another film for another production company for that particular time slot. In turn, for every single film, studios (and ultimately their investors, shareholders, or backers) end up bearing massive transaction costs because they not only have to get the right person at the right price, but at the right time, and if they cannot get that person, they have to scramble to locate a satisfactory substitute. All successful directors and producers have certain favorite cast and crew members whom they prefer to work with, but that is of no help to the studio if that perfect character actor, costume designer, or music composer is already fully booked. Compared to the previous system, directors and stars spend a much "larger part of their time negotiating each new film deal."
Therefore, if a film does well at the box office and appears to have established a winning formula with a particular cast, crew and storyline, one way to minimize these transaction costs on sequels is to reassemble as much of the team as soon as possible (before anyone dies, retires, or commits to other possible scheduling conflicts) and sign them to a single production that will be edited, released, and promoted as multiple films. This also minimizes the problem of stars visibly aging between sequels that do not have significant time gaps written in between them.
The pioneer of modern back-to-back filmmaking was producer Alexander Salkind, who decided during the filming of The Three Musketeers (1973) to split the project in two; the second film was released as The Four Musketeers (1974). The cast was quite unhappy to be informed after the fact they had been working on two films, not one. As a result, the Screen Actors Guild introduced the "Salkind clause," which specifies that actors will be paid for each film they make. Salkind and his son Ilya went on to produce Superman and Superman II back to back.
- Superman and Superman II were filmed simultaneously in 1977 to be a two-part epic. However, due to off-screen difficulties between the producers and director Richard Donner, production on the sequel was stopped in order to finish the first film for a December 1978 release. Filming on Superman II resumed in 1979 with a new director (Richard Lester), and was released in Australia in December 1980 and in the UK and US in 1981.
- After the success of the 1985 film Back to the Future, the two sequels Part II and Part III were in production from February 1989 until January 1990 with only a three-week break in principal photography between films and some of the filming of the third film overlapping with the second. The two films were released six months apart, in November 1989 and May 1990 respectively.
- The Lord of the Rings trilogy was filmed entirely over 438 days in New Zealand from October 1999 until December 2000 with pickup shots done prior to each film's theatrical release from 2001 to 2003. Likewise, The Hobbit trilogy was filmed back-to-back in New Zealand from March 2011 until July 2012.
- The Matrix Reloaded and The Matrix Revolutions were filmed back-to-back from March 2001 until August 2002, and released six months apart, in May 2003 and November 2003 respectively.
- Pirates of the Caribbean: Dead Man's Chest and Pirates of the Caribbean: At World's End were filmed back-to-back from February 2005 until January 2007, and released a year apart, in July 2006 and May 2007 respectively.
- Fifty Shades Darker and Fifty Shades Freed were filmed back-to-back from February 2016 until July 2016. The two films were released a year apart, in February 2017 and February 2018 respectively.
- Avengers: Infinity War and Avengers: Endgame were filmed back-to-back from January 2017 until January 2018, with reshoots for the second film concluding in October 2018, with the films released a year apart, in April 2018 and April 2019 respectively.
- Staiger, Janet (1985). "Chapter 26: The package-unit system: unit management after 1955". In Bordwell, David; Staiger, Janet; Thompson, Kristin (eds.). The Classical Hollywood Cinema: Film Style & Mode of Production to 1960. New York: Columbia University Press. p. 330. ISBN 9780231060554.
- Bingen, Steven (2014). Warner Bros.: Hollywood's Ultimate Backlot. Lanham, MD: Rowman & Littlefield. p. 198. ISBN 9781589799622.
- Staiger, Janet (1985). "Chapter 26: The package-unit system: unit management after 1955". In Bordwell, David; Staiger, Janet; Thompson, Kristin (eds.). The Classical Hollywood Cinema: Film Style & Mode of Production to 1960. New York: Columbia University Press. p. 334. ISBN 9780231060554.
- Jackson, Gordon; Anders, Charlie Jane (31 July 2015). "Has Filming A Movie And Its Sequel Back-to-Back Ever Had a Good Result?". Gizmodo. Retrieved 26 May 2020.
- Salmans, Sandra (17 July 1983). "Film View: The Salkind Heroes Wear Red and Fly High". The New York Times. The New York Times Company. p. 15. Retrieved 26 May 2020.
- Scivally, Bruce (2008). Superman on Film, Television, Radio and Broadway. Jefferson, NC: McFarland. p. 77. ISBN 9780786431663.