The Public Boadcasting System annually packages a number of shows resent engaging material somewhat afield from the more structured offerings of the commercial networks.

"An extraordinary range of viewing choices," is the way PBS folks are prone to tout their stuff. This season public TV's fall package stacks up favorably with its preseason billing.

The slogan says, "Public TV is TV worth watching." And, what comes forth -- from more than a dozen noteworthy specials, six new series, and some improved new episodes on established series -- is going to be worth watching.

"War: A Commentary by Gwynne Dyer" heads the 1985 PBS class. Two centuries of world military history, from the Napoleonic Wars to the Falklands and the ongoing Middle East confrontations, are traced by Canadian journalist Dyer, who explores the political ideals, military strategies and the price mankind paid for war. The seven-part series premieres on Oct. 1.

The show that could garner the most notice on PBS this fall is "The Skin Horse" (Oct. 16), treading new and sensitive waters. Since the early '60s, TV has explored most aspects of human sexuality, save one -- the sexuality of severely disabled people. This show does just that.

"Lone Star," which explores the legend of Texas and the reality behind the mystique, will highlight the late season offerings with dates to be announced. This eight-part series, three years in the making by KEDT of Corpus Christi, is hosted by Larry Hagman of the hit "Dallas" series. The legend, the land, the cowboys, the oil, and everything that is Texas from armadillos to pigskins is explored in this series based on a book by renowned Texas historian T.R. Fehrenbach.

Some of the special new treats on PBS are found under venerable headings of "Great Performances" (13th season), "Nova" (13th season) and "Masterpiece Theatre" (15th season).

Great drama tops the "Great Performances" lineup beginning with Graham Greene's "Dr. Fischer of Geneva" (Oct. 11), the tale of a wealthy eccentric who delights in probing the greed of the rich. It stars Alan Bates, the late James Mason (his final performance) and Greta Scaachi. On Oct. 25 and Nov. 1 comes "Laurence Olivier -- A Life," a two-part biography, followed at a later date by Matthew Broderick in "Master Harold . . . and the Boys."

Multi-award winning "Nova" features include "What Einstein Never Knew" (Oct. 22), which probes the quests of a new generation of physicists to explain the enigma of the universe; "Technology at Work" (Oct. 29), which looks at the implications surrounding computer automation; and "Tornado" (Nov. 19), a scoot across the plains of Oklahoma with a "chase team," the guys that run toward and not away from tornadoes.

"Masterpiece Theatre" will lead off with a six-part dramatization of the 1911 Scott- Amundson race to the South Pole titled "The Last Place on Earth" (Oct. 20-Nov. 24). This series tells how Scott and Amundson hustled man and money in England and Norway for their expedition and then recounts the drama of their journeys across Antarctica.

Dylan Thomas' final work, "Under Milk Wood" (Wednesday), is without plot but with priceless characters who dream aloud. The cast includes the late Richard Burton, Elizabeth Taylor, Peter O'Toole, Glynis Johns, Sian Phillips, Vivian Merchant, Angharrad Rees and Victor Spinetti.

"Treasure Houses of Britain" (a three- part series beginning Dec. 16) will draw special interest in this area. The unprecedented views of some of Great Britain's most magnificent country homes from the 15th through the 19th centuries coincides with the National Gallery of Art's winter exhibit, "The Treasure Houses of Britain: Five Hundred Years of Private Patronage and Art Collecting," showing from Nov. 3 to March 16.

"The Times of Harvey Milk," a 1985 Academy Award Winner for best documentary, comes to PBS on Nov. 13. This significant presentation traces the rise, political career and assassination of the country's first openly gay elected political official, Harvey Milk of San Francisco.

Timothy Harris will host the explanation of new scientific theories on "the Creation of the Universe" (Nov. 20).

A contest that all sides can enjoy comes up on "Black Magic" (Monday), a rope jumping contest won by four inner city girls from Hartford, Conn. The prize was a trip to England. And, the dialogue of the winners, who had never been outside their home state, could never come from a script.

The 1986 reappearance of Halley's Comet, most famous of all comets, and the rare opportunity to view it spurred "Comet Halley" (Nov. 26), a historical, scientific and cultural examination of the significance of comets.

Also jumping the gun on another 1986 media super event is "The Statue of Liberty" (Oct. 28), a one-hour documentary narrated by historian David McCullough about the soon-to-be 100- year-old monument, a creation of sculptor Frederic Auguste Bartholdi, who wasn't even sure he liked Americans.

PBS is not without humor this fall. Try "Penn & Teller Go Public" (Oct. 23). These bad boys of magic are unlike any magicians you've watched before. Call 'em magical comedians or comedic magicians, either way they are original. Also on the light side is "The Booth" (Oct. 9), which uses a restaurant booth as the setting for three light-hearted dramas starring Dame Judith Anderson, Rene Auberjonois, James Coco, Peter Coyote, Teri Garr, Barnard Hughes, Mary Kay Place and Mildred Natwick.

Then there is "Crabs," a Maryland- produced show that has been called "Maryland's Saturday Night Live." It opened last season and used Marylanders to poke fun at the state's people and places. The show usually follows six episodes of the "Mark Russell Comedy Special" this fall and winter. However, the next "Crabs" show, Nov. 10, will precede "Mark Russell."

Beverly Sills hosts a three-part "On Stage at Wolf Trap." On Wednesday, Mstislav Rostropovich conducts the National Synmphony Orchestra in Shostakovich's Fifth Symphony for the first time on TV. Two masters of jazz, Ella Fitzgerald and Oscar Peterson, take center stage on November 26. The first part of this special, the Preservation Hall Jazz Band, aired Sept. 2. But expect encores.

"When Mountians Tremble" (Oct. 2) is a story by Rigoberta Menchu that pulls together Guatemala's recent history, the beauty of its culture and the courage of its people as well as their greed and corruption.

The 1984 Summer Olympic Games and the 80,000 people who were involved in organizing and producing those memorable moments from Los Angeles come to life in "Olympic Challenge" (Oct. 13). The show follows key people in security, sports, transportation and medicine through many frustrations to opening ceremony triumphs.