On Jan. 22, Playboy magazine leaps from behind the drugstore counter onto the cable television screen in what will be called ''The Playboy Channel.''
The channel features the type of material for which the publication is known: everything ''from automobiles to erotica, stereos to sex,'' according to the slick, classy promotional package. Adult movies and filmed photography sessions for centerfold ''Playmate'' models also will be included and will be accessible in at least 200,000 households throughout the United States.
This is the latest example of inroads into the cable market being made by ''adult'' cable services with names like ''Eros,'' ''Escapade,'' ''Private Screenings,'' and ''Adults Only.
At the current rate of growth, nearly 50 percent of the US households with televisions will be wired for cable by 1989, according to projections made for the National Cable Television Association (NCTA). During the past few years, well over half the cable-TV viewers in some urban areas who were given the option to purchase an additional adult channel did so, according to several cable franchise operators.
To some parent and religious groups, this trend underscores the potential for widespread distribution of everything from soft-to-hard-core pornography via cable. They are concerned that the moral fiber of their community could fray if other parents choose to expose their children to adult programming.
''The ability (the cable industry) will have to put on hard-core pornography frightens me,'' says Robert Ward, vice-president of the Boston chapter of Morality in Media, the largest group opposing adult programming on cable. The chief reason for his concern -- and one that is shared by many other observers -- is the effect of such programming on children.
''It's not a matter of kids learning about sex earlier than you might want them to,'' explains Kim Hays, executive director of the nationwide Action for Children's Television (ACT), ''it's howm they learn it.''
Adult programming represents a small amount of the total cable programming being produced. Some who have studied the cable industry say estimates on the potential market for adult channels are inflated, as are reports of the amount of adult material now being distributed. Most local cable operators, concerned about community backlash, steer clear of airing anything that smacks of ''hard core'' pornography.
But a writer for a trade publication of satellite-TV and other cable industry observers indicate that ''pay-TV'' services and late-night cable ''add-on'' channels are growing bolder in the amount of sexually explicit or violent material they offer.
There is a variety of adult-oriented services. Some are clearly identified as adult fare, ranging from R-rated box office hits to low-budget films. There are all-movie channels and those that combine cartoons, adventure features, and comedy-variety shows with sexual themes.
Other services provide a variety of entertainment, but often include material that some parents would not want children to view. Home Box Office, for example, features R- and PG-rated films such as ''Kramer vs. Kramer'' (which includes a brief nude scene) and ''10'' (which has nudity, profanity, and sexual themes), as well as cartoons for children.
In areas where adult-oriented cable channels are available, they are almost always an add-on option for an extra few dollars a month. Cable companies receive the programs from satellite services and split the revenues. Very little is locally originated.
In towns not yet wired for cable, direct over-the-air satellite broadcasts known as subscription TV are available on a ''scrambled'' UHF channel.
While most of the nationwide TV watchdog organizations are pinpointing their efforts at commercial TV, most of the opposition to adult cable services is mounting at the community level, where cable franchises are awarded. But already , attempts by local authorities to restrict cable content have been ruled unconstitutional in court, and local and state officials are looking to the federal government for guidance on the touchy issue.
They're getting little help.
In previous cases involving books and broadcasts, the US Supreme Court has found it nearly impossible to come up with a universally applicable definition for pornography. The Federal Communications Commission (FCC), which sees to it that broadcasts over public airwaves are in ''the public interest,'' has all but relinquished control over cable, according to one communications expert. ''Community standards,'' say top FCC officials, should determine the issue.
But because the issue involves the First Amendment right to free speech as it applies to cable, groups such as American Civil Liberties Union (ACLU) are likely to keep a close eye on local efforts to regulate programming. The result may be a landmark legal battle, forcing into the open questions that courts have been wrestling with for years:
* Is cable TV a public utility, as some suggest? Is its role similar to that of broadcast television, a public service medium? Is cable akin to the theater, where patrons deliberately pay to see a show - or more like books, magazines, and video cassettes, which are viewed in the privacy of one's own home?
* What happens when someone's First Amendment right to free speech offends community standards of acceptable TV content?
* Should anyone be permitted to dictate what others can watch in their own homes? In essence, does society have an obligation to protect people from themselves?
* What constitutes pornography, obscenity, and indecency? Is there an objective standard? How do these terms relate to ''R'' and ''X'' ratings by the Motion Picture Association of America? Are nudity, sexual themes, and vulgar language more acceptable in movies with compelling plots than in films that mainly try to exploit human sexuality?
The scope of the problem is monumental, and will probably take years to resolve. Officially, the cable industry is taking refuge under the umbrella of the First Amendment. Industry officials say that to allow government controls on program content will open the floodgates of censorship to right-wing religious groups, which seek stiff controls on television. The National Cable Television Association opposes the showing of X-rated material. But its policy is not binding on its 1,800 members, who service 70 percent of all cable viewers.
Unofficially, some cable officials admit there are almost no limits to what could be aired on cable. Their solution, in essence: If you don't like it, don't buy it.
''Deliberately -- every 30 days - you have to pay for it (cable) and say 'I want this in my home,' '' says one cable-TV lawyer in Washington, who asked not to be named. He says ''the power of the purse'' will determine if adult programming is a success or failure.
''Don't tell me it's against the law[to air adult shows],'' he says. ''Tell me I'm going to go out of business if I run this junk.
''But what if there is a market for ''junk''?
''Is it OK just because people will buy it?'' asks Morality in Media's Mr. Ward. ''Does that justify the free-flow of pornography?''
The cable attorney admits problems of ethics may surface. ''Cable can provide a lot of revenue to a town,'' he says. So if the majority of residents in a community oppose adult programming, a city councilor would have to choose between satisfying the conservative majority or making money off of the minority.
The bottom line, according to cable executives, is that the franchise owner has to satisfy customers, not offend them. Boston alone will cost $100 million to wire for cable within the next three or four years, according to a cable-TV official in Washington, and cable companies must adhere to the moral standards of their customers in order to make their investments pay off.
Meanwhile, programmers of adult material, lured by what they see as a lucrative new market, appear to be taking advantage of the confusion in the courts and are eager to become established while cable is young. There is a huge , untapped demand for adult material, those in the business say. In fact, most quickly add that the only complaints they receive are from viewers who say the stuff is too mild and not worth the extra money.
The Twin County Trans-Video Company of Allentown, Pa., which currently is the only cable franchise in the US to run X-rated films, ''got into it because our customers asked for it,'' says Donald Berner, the company's vice-president. Twin County Trans-Video offers one channel that shows ''nothing but X,'' he says, ''so if customers order it, they know exactly what they're getting.''
That is not always the case elsewhere. In New York City, two late-night shows -- ''The Ugly George Hour of Truth, Sex, and Violence'' and ''Midnight Blue'' -- are airing crudely made films shot in downtown sex clubs and adult dance shows. ''Ugly George'' totes a camera around Manhattan, convincing women to undress in alleys and hallways on film.
These and other hard-core shows were made possible in New York City by an FCC rule -- now rescinded under the deregulation of the communications industry -- that required cable franchises to provide a number of ''public access'' channels , combined with a state law that prevents cable companies from editing or censoring programs. Manhattan cable customers have no choice but to find ''blue'' channels alongside regular cable program spots on their selector switches, because the blue channels are not special ''add-ons'' and there is no way to screen out the adult segments.
Ironically, what was designed to encourage local cultural and minority-oriented programs has in this instance become the medium for TV sex.In the 1974 case ofMiller v. Californiam the Supreme Court set down three criteria to define ''obscenity'': First, the dominant theme of the material must appeal to a ''prurient interest'' as judged by ''contemporary community standards''; next, it must depict sexual activity in a ''patently offensive manner''; finally , it must lack ''serious literary, artistic, political, and scientific value.''
These standards are adequate to guard against the airing of obscene material on cable, according to NCTA spokesman Ed Dooley.
However, the obscenity clause has yet to be applied to cable TV in court. And a number of lawyers interviewed say it would be nearly impossible to prove all three conditions in an obscenity case. In New York City, for instance, it would be difficult to prove that ''Ugly George'' was actually violating ''community standards.''
Nevertheless, Morality in Media and other groups have attempted to ban from cable TV not only obscenity, but ''indecency,'' a term the courts have not defined. The word is often used to refer to ''offensive'' material, which, in the opinion of Morality in Media, includes both X- and R-rated films.
Barton Carter, a communications attorney and assistant professor at Boston University (BU), who acted as a consultant in the Boston cable franchise negotiations, says most indecency laws are too subjective and broad, and won't hold up in court.
''People . . . are drafting them emotionally, not legally,'' he says.
Last November, a US district court judge in Utah struck down a state indecency law. Faith Wender, an attorney for Home Box Office, which was involved in the case along with the ACLU, says the law would have prohibited even R-rated , academy award-winning movies such as ''Kramer vs. Kramer.''
Under such a law, ''You'd probably have to empty most of the art museums and the libraries,'' says -Albert Baxter, a spokesman for the FCC's Cable Bureau.
Milwaukee passed a similar law last year, which city officials admit will probably be challenged. A bill to prohibit X- and R-rated programs from 10 a.m. to 6 p.m. is being submitted for the second time to the Florida Legislature. And Massachusetts Gov. Edward J. King is reviewing a bill modeled after Morality in Media standards.
Instead of taking actions that may infringe on First Amendment rights, cities and towns can take other formal and informal steps to ensure they get the quality of programming they want.
* During the franchising process, areas that do not yet have cable service can negotiate for the type of programming they desire. Where a cable franchise already exists, towns can refuse to renew the contract of the company unless the programming meets local preferences. If a town and the cable company agree to restrict X- and R-rated material, the contract will ''probably'' hold up in court, according to Dr. Carter. But he adds that this type of arrangement hasn't been tested yet.
* During franchising, towns can demand that cable operators provide to every customer a free ''lock-box'' or ''parental guidance key,'' so parents can shut off cable channels when they aren't around to supervise their children. In addition, Dean Smith says that before being transmitted, movies can be electronically ''tagged'' as PG, R, or X, and cable converters on the television set can be programmed to automatically lock out the type of movies to which parents object.
* One informal check on cable programmers is the fact that most are seeking franchises in other areas. Thus, they will likely avoid a bad reputation at all costs. Jake Smith, assistant dean of BU's School of Public Communication, who also assisted Boston in its franchising process, says the threat of bad publicity will be an effective restraint on cable companies as long as there are still franchises available.
Almost everyone agrees that it is the attitudes of parents that will ultimately make the difference in cable programming.
''Who is running the morals of the home - the legislature, cable, or the parents?'' asks one cable executive. ''I think it should be up to the parents.''
In ''Cable and Children: an ACT Handbook,'' the group suggests that cable companies offer more detailed program guides, so parents can make better-informed decisions on what their children watch.
But the content of cable programming should not be decided by just a few people, warns Kim Hays of ACT.
''Our First Amendment freedoms are very precious to us. Freedom means . . . doing things that not everybody's going to like.
''Cable has such a good opportunity to fill some of the gaps in children's programming. . . . We're counting on cable.''