Most American dramas and comedies begin with a scene before the credits roll. That placement is a deliberate response to how audiences decide whether to keep watching.
The first minute decides continuation
Viewers make a keep-or-leave decision very early, whether they are flipping channels or scrolling a menu. A title sequence at the top spends that window on branding.
Putting a scene first uses the window on story instead. By the time credits appear, the viewer has already committed to something specific.
Streaming intensified this. A viewer who has not been given a reason within seconds returns to the browsing interface, where every competitor is one click away.
Broadcast structure created the shape
Commercial television is built in acts separated by breaks. The cold open functions as a short act zero delivered before the first break arrives.
Its length is therefore constrained by the schedule rather than by the story. Writers learn to land a hook inside a fixed number of pages.
Streaming shows inherited the convention even without commercial breaks, because the writers and showrunners trained in the broadcast system.
Different genres use it differently
Procedurals typically open on the discovery that starts the case, often featuring characters the audience will never see again. The purpose is to pose the question.
Comedies use it as a self-contained joke with no plot function at all, establishing tone rather than stakes.
Serialized dramas frequently open on a flash-forward or a fragment out of sequence, creating a gap the episode then closes.
Title sequences shrank as a consequence
When the opening scene carries the hook, the title sequence becomes a breath rather than an introduction. Many modern shows reduce it to a few seconds.
Skip controls accelerated the shrinkage. A sequence most viewers bypass is difficult to justify at the length older shows used.
Some shows abandoned the sequence entirely, placing a title card over the first scene instead. The cold open then becomes simply the beginning.
The cost is a scene that must work twice
A cold open has to be intriguing without context and satisfying in retrospect once the episode explains it. Few scenes carry that double burden well.
Weak versions front-load a shock the episode never earns, which trains regular viewers to discount the opening entirely.
The strong ones plant something the audience only recognizes on a second viewing, which is why the device persists rather than being abandoned as a gimmick.