Science fiction first appeared in television programming in the late 1930s, during what is called the Golden Age of Science Fiction. Special effects and other production techniques allow creators to present a living visual image of an imaginary world not limited by the constraints of reality.

The need to portray imaginary settings or characters with properties and abilities beyond the reach of current reality obliges producers to make extensive use of specialized techniques of television production.

Through most of the 20th century, many of these techniques were expensive and involved a small number of dedicated craft practitioners, while the reusability of props, models, effects, or animation techniques made it easier to keep using them. The combination of high initial cost and lower maintenance cost pushed producers into building these techniques into the basic concept of a series, influencing all the artistic choices.

By the late 1990s, improved technology and more training and cross-training within the industry made all of these techniques easier to use, so that directors of individual episodes could make decisions to use one or more methods, so such artistic choices no longer needed to be baked into the series concept.

Special effects (or "SPFX") have been an essential tool throughout the history of science fiction on television: small explosives to simulate the effects of various rayguns, squibs of blood and gruesome prosthetics to simulate the monsters and victims in horror series, and the wire-flying entrances and exits of George Reeves as Superman.

The broad term "special effects" includes all the techniques here, but more commonly there are two categories of effects. Visual effects ("VFX") involve photographic or digital manipulation of the onscreen image, usually done in post-production. Mechanical or physical effects involve props, pyrotechnics, and other physical methods used during principal photography itself. Some effects involved a combination of techniques; a ray gun might require a pyrotechnic during filming, and then an optical glowing line added to the film image in post-production. Stunts are another important category of physical effects. In general, all kinds of special effects must be carefully planned during pre-production.

Babylon 5 was the first series to use computer-generated imagery, or "CGI", for all exterior space scenes, even those with characters in space suits. The technology has made this more practical, so that today models are rarely used. In the 1990s, CGI required expensive processors and customized applications, but by the 2000s (decade), computing power has pushed capabilities down to personal laptops running a wide array of software.

Models have been an essential tool in science fiction television since the beginning, when Buck Rogers took flight in spark-scattering spaceships wheeling across a matte backdrop sky. The original Star Trek required a staggering array of models; the USS Enterprise had to be built in several different scales for different needs. Models fell out of use in filming in the 1990s as CGI became more affordable and practical, but even today, designers sometimes construct scale models which are then digitized for use in animation software.