A cold open (also called a teaser, or just a cold, especially in production circles) is a narrative tactic used in television and/or films. It is the technique of jumping directly into a story at the beginning or opening of the show before the title sequence or opening credits are shown. On television, this is often done on the theory that involving the audience in the plot as soon as possible will reduce the likelihood of their switching from a show during the opening commercial. A cold open may also be used to recap events in previous episodes or storylines that will be revisited during the current episode.
The cold open technique is sometimes used in movies. There, "cold opening" still refers to the opening moments or scenes, but not necessarily to the full duration before the title card, as the title card might appear well after the cold open has been achieved.
In the early 1960s, few American series used cold opens, and half-hour situation comedies almost never made use of them prior to 1965. Many American series that ran from the early 1960s through the middle years of the decade (even sitcoms) adopted cold opens in later seasons; for example, Gilligan's Island did not use cold opens during its first two seasons, but did use them in its third and final year (1966–67). They were used on some seasons of Mission: Impossible, likewise with Hawaii Five-O. Many other long-running TV series used cold opens; similar patterns can be seen with sitcoms, including Bewitched and The Beverly Hillbillies.
Cold opens became widespread on television by the mid-1960s. Their use was an economical way of setting up a plot without having to introduce the regular characters, or even the series synopsis, which would typically be outlined in the title sequence itself. The Man from U.N.C.L.E. (1964–68) and Star Trek (1966–69) or the earlier Bonanza (1959-1973) are examples in the United States. In the United Kingdom, the format was usually utilized only in series destined for the American market, such as The Avengers (1961–69) and The Saint (1962–69).
Toying with many television conventions, Monty Python's Flying Circus (1969–74) played around with the concept of cold opens. Sometimes an entire episode aired before the starting credits. Two instances had no opening credits at all: "The Cycling Tour" shows a brief title card with the episode's title before becoming the first episode to have a full-length story, and "The Golden Age of Ballooning" (the first episode of season four) has no titles because Terry Gilliam had not finished the new opening sequence.
British producer Lew Grade's many attempts to break into the American market meant that various shows he was involved with incorporated the cold open, such as The Persuaders! (1971) and Space: 1999 (season one only, 1975). Later, many British action-adventure series employed the format, such as The New Avengers (1976–77) and The Professionals (1977–81).
During the 1960s and 1970s, daytime soap operas became the main user of cold opens, with most American soaps employing the format.
In the late 1970s and early 1980s, some shows began with highlights from the previous episode.
The popular long-running sitcom Cheers in the 1980s and 1990s always had a short scene before the title sequence which usually did not relate to the main theme of the episode.
Documentaries do not use cold openings as frequently as fictional shows. The World at War (1973–74) is one famous exception, where in a few short minutes an especially poignant moment is featured; after the title sequence, the events that explain the episode are outlined more fully.
The cold open became common if not standard for sitcoms in the early 1990s. U.S. sitcom and drama episodes often have a traditional cold opening, which usually sets up the plot using the main cast members (e.g., Friends). Some sitcoms, however, use cold opens which have nothing to do with the plot of an episode (e.g., Malcolm in the Middle).
Many cold openings in sitcoms do not set up the plot but usually involve physical comedy or bantering, such as numerous cold opens from the popular NBC sitcom, "The Office". Closing credits of a sitcom often feature a scene between characters that does not have any relevance to the plot. In the show It's Always Sunny In Philadelphia, created by Rob McElhenney, the opening of every episode has a cold opening with a caption stating the time and day of that scene's events.
The World at War famously uses a cold open during its first episode opening, during which the story of Oradour-sur-Glane is told. This particular event takes place in mid 1944, whereas the rest of the episode takes place in the 1930s.
In Ken Burns's The Civil War, the opening of the first episode describes events taking place in 1865, whereas the rest of the series takes place chronologically during 1861-1865.
The long-running NBC sketch comedy show Saturday Night Live has usually employed a cold open, except for season 7 and other rare presentations. The cold open usually ends with someone breaking character and proclaiming "Live from New York, it's Saturday Night!"
The second-incarnation PBS Kids Go! sketch comedy and education program The Electric Company features a cold open introducing the plot, ending with one of the Company members yelling "Hey, you guys!!"
Cold opens are common in science fiction dramas, such as Star Trek, and crime dramas, such as all Law and Order variants and the CSI shows, with the crime being committed before the title sequence. CSI: Miami's version of this cold open style is famous and widely parodied; generally, Horatio Caine makes a dramatic comment on the crime (and then puts on or removes his sunglasses while doing so), immediately followed by the iconic scream ("Yeah!") from The Who's "Won't Get Fooled Again", the show's opening theme. 1970s drama The Rockford Files' typical cold open consisted of Jim Rockford's outgoing message on his answering machine followed by a message left by a caller, sometimes incidentally related to the show to follow, but oftentimes not. Episodes of the medical drama House would begin with a cold opening usually showing the patient collapsing or otherwise showing symptoms that would be central to that episode's plot. In the U.S., TV shows will occasionally forgo a standard cold open at the midway point of a two-part episode, or during a "special" episode. For example, Buffy the Vampire Slayer's fourth-season finale lacked a cold open, as it was an unusual dream-centric episode. Cold openings featured in several Australian drama series, including McLeod's Daughters (2001–2009). Vince Gilligan has been declared "Undisputed Master of the Cold Open" in multiple reviews  detailing particular episodes of Better Call Saul and Breaking Bad.
While several soaps experimented with regular opens in the early 2000s, all U.S. daytime dramas are currently using cold opens. Typically, a soap opera cold open begins where the last scene of the previous episode ended, sometimes replaying the entire last scene. After several scenes – usually to set up which storylines will be featured in the episode – the opening credits are shown. On the contrary, most British soap operas typically begin with regular opens.
In film production, the section of the film before the opening credits is called the pre-credits, and they are sometimes crafted as a cold open.
In some movies, the title card does not appear until the end. In such cases, one cannot refer to the entire movie as the "opening", and the term "cold open" in these instances refers to the opening moments or scenes.
Likewise, in movies with excessively long pre-credits sequences, the "cold open" does not necessarily refer to the entire pre-credits sequence. For example, James Bond films use pre-title sequences; these are not considered teasers.
Cold opens were also an occasional device in radio. Jack Benny's weekly program would usually begin with Don Wilson reading standard copy announcing the name of the program and introducing the stars. Sometimes, however, particularly for a show at the start of a new season, the actors would launch into material without any announcement and perform a sketch written to give the audience the impression they were eavesdropping on the stars' off-microphone lives. That would be followed by the more standard Don Wilson introductions and the show would proceed as usual after that. The BBC sketch comedy show The Burkiss Way often played with continuity, including occasional misplacing of the opening credits.
Today, the nonfiction radio program This American Life uses a cold open for its episodes.
Many video games have included cold opens. These either begin with a lengthy opening sequence or, like Grand Theft Auto V or the Metal Gear Solid games, include an entire level before the titles. It is common in Japanese RPGs, with the original Final Fantasy an early example. Both Wild Arms and Kingdom Hearts II went as far as including an entire subplot, often taking upwards of three hours to play through, before showing the game's logo.
Another example is Assassin's Creed: Brotherhood, in which Ezio escapes Monteriggioni; after performing a leap of faith, the camera does not follow him and the Assassin's Creed logo is shown. The opening sequence in Need for Speed: Undercover was also an example, with a police chase scene that the player can take part in, which was followed by a full motion video cinematic and the game's logo. X-Men 2: Clone Wars is perhaps the best example, as the player is taken directly to the game's first level upon powering the game on, skipping any title screen or even a character select screen until the first stage is completed.
Cold opens sometimes employ a segment known as a "teaser" or "tease". A memorandum was written by Gene Roddenberry on 2 May 1966, as a supplement to the Writer–Director Information Guide for the original Star Trek series, describing the format of a typical episode. This quotation refers to a cold open, commonly known as a teaser:
The "hook" of the teaser was some unexplained plot element that was alluded to in the teaser, or cold open, which was intended to keep audiences interested enough in the show to dissuade them from changing stations while the titles and opening commercial roll. Star Trek writer David Gerrold, to tweak William Shatner on set, once joked he was writing a Star Trek episode in which Kirk lost his voice in the teaser (the hook), and did not get it back until the tag. Gerrold states that Shatner's comment about this suggested episode was, while not unprintable, sufficiently humiliating to prove that "hire guns should not draw down on top guns".
In television series, a similar technique called a cliffhanger is often employed before commercial breaks, to keep the audience from switching channels during the break. For instance, in Law & Order this second hook is often the arrest of the suspected perpetrator of the crime committed in the cold open.
The companion closing scene at the end of a show is known as the "tag".