A couple of distributors have done some effective jockeying for position at the start of the summer movie season. For example, moving "Conan the Barbarian" up a week allowed Universal to realize a substantial opening weekend ($10 million). When business slumped 35 percent in the second weekend, the studio was still nicely placed with the opening of "Dead Men Don't Wear Plaid," which also got off to a strong start and faded in subsequent weeks. Of course, the company is sitting pretty for the entire season on the strength of Spielberg's masterpiece, "E.T.," which went into release last weekend.

In the meantime, MGM/UA had moved up "Rocky III," originally booked to open the same weekend as "E.T.," which ended up overwhelming a token competitor, "Grease 2." The result for "Rocky III" was a big, unmolested opening weekend, and the movie declined a trifling 10 percent or so in its second week, when MGM/UA launched another potent attraction, Spielberg's "Poltergeist."

Paramount had "Star Trek II" nicely position to cash in the week before "E.T." arrived and should probably have bailed out "Grease 2" by postponing it until later in the summer. Heaven knows it's a livelier musical than "Annie."

The least astute decision may have been the launching of Caleb Deschanel's lovely but elusive first feature, "The Escape Artist," in a few major markets two weekends ago. It seemed almost guaranteed to be obscured by the gaudier competition. Evidently, Filmways/Orion intends to look for a less congested period in late summer or early autumn to present the movie in Washington and other cities. Former AFI staffer Stephen Zito shares credit on the screenplay, derived from a 1965 David Wagoner novel, with Melissa Mathison, who also wrote "E.T." for Spielberg and collaborated on Carroll Ballard's "The Black Stallion," which was photographed by Deschanel.

The jockeying continues: "Blade Runner," Ridley Scott's ambitious but iffy attempt to transform Philip K. Dick's science-fiction novel "Do Androids Dream of Electric Sheep?," a contradictory mixture of witty futuristic speculation and conventional hard-boiled detective melodrama, into a popular movie was scheduled to open this Friday, when it would have faced "Annie," the comedy "Author! Author!," Clint Eastwood's "Firefox" and the revival of "Bambi." It's now been postponed until June 25, when the competition consists of another science- fiction thriller, "The Thing," and Hal Needham's far-fetched action spectacle "Megaforce." Presumably, the shift was made to avoid being obscured by "Annie." The rather murky "Blade Runner" probably will stand a better chance of rallying a cult audience than the supposedly surefire "Annie" will of holding a vast family audience.

Two late-summer releases have undergone title changes. The Bette Midler caper comedy originally called "Jinxed" and then changed to "Three of a Kind" has been changed again to "It's All in the Game." A new Chuck Norris action vehicle known as "The Jade Jungle" during production will evidently be entering the market in August as "Forced Vengeance."

The American Film Institute Theater resumes its popular series "Cult Movies" in mid-August with a double-bill of "Phantom Lady" and "Point Blank," but the bill to cherish is a surreal degradation combination scheduled for Friday and Saturday, August 27-28: Bette Davis going to the dogs in King Vidor's delirious "Beyond the Forest" plus Joan Crawford ruining lives in "Queen Bee," a 1955 vehicle that cast as her as the shrewish, tyrannical wife of a mill owner. According to Christina Crawford's scandalous recollections, the "Queen Bee" character closely resembled the Mommie Dearest she knew and feared. As part of the Shakespeare exhibit now the Kennedy Center, the AFI Theater will also host free showings of nine BBC Shakespearean productions on Saturdays at 2 p.m. The series begins tomorrow with "A Midsummer Night's Dream."

The Sidwell Friends Cinema begins daily repertory film showings this Tuesday evening at the campus' Arts Center. Expanded from a successful program of occasional weekend showings during the school year, the series will run through August 7. The opening bill is Hitchcock's "The 39 Steps" and "The Lady Vanishes." The bills change each Monday, Wednesday and Friday. All admissions are $2.50; the management plans to offer $10 subscription books good for seven admissions. For further information on programming drop by the auditorium at 3825 Wisconsin Ave. NW or call 537-8178.

Though new professional obligations prevent him from reviving his popular seminars on screenwriting, Prof. Sheldon Tromberg has announced his availability this summer to specially selected aspirants who might find private, flextime tutorial sessions useful. Ditto for stymied amateurs seeking a collaborator or script doctor for scenarios- in-progress. Those interested in the course of instruction may obtain detailed information by calling Tromberg at 484-5620.

Judy Riggin, an associate professor of English at Northern Virginia Community College, is offering a course on the movie musical at the Annandale campus Thursday evenings starting June 24. The examples she plans to use include "Top Hat," "Gold Diggers of 1935," "Yankee Doodle Dandy," "Meet Me in St. Louis," "On the Town" and "Cabaret." For details call 323-3193.

Kermit Moyer, an associate professor of literature at American University, will conduct a film-and-lecture series called "Masterpieces of Cinema" under the auspices of the Smithsonian Resident Associates beginning Monday July 12. The six-week course, meeting Mondays at 6:30 p.m., includes screenings of "The Third Man," "City Lights," "Rashomon," "The Seventh Seal," "The Rules of the Game" and "North By Northwest." Fees will be $46 for Smithsonian members and $59 for non- members. Call 357-3030 for further information.

The Washington Area Film/Video League is sponsoring a workshop called "Organizing With Media" Saturday from 10 a.m. to 4 p.m. at the AFI. Registration fees are $25 for members, $35 for non-members. Call 783- 0400 for detailed information. The same organization in sponsoring a free seminar on filmmaking services in Washington, D.C. Wednesday at 7:30 p.m. in the mayors' conference room, fifth floor of the District Building at 1350 Pennsylvania Ave. NW. Richard Maulsby, director of the city's Office of Motion Picture and Television Development, will preside. Finally, WAF/VL also plans a screenwriting workshop Saturday, June 26, from 10 a.m. to 3 p.m. at the AFI conducted by playwright-scenarist William Hauptman. The same fees and phone number mentioned above apply.