Robert Gest IV, a quiet Prince George's high school senior, began working at the age of 13 for an appointment to one of the service academies that turn out the nation's top military officers.

He studied four hours a day in addition to a full day at school, earning top grades during his scholastic career.

He filled his life with the kind of activities he believed would impress the Army's institution at West Point, the Naval school in Annapolis and the Air Force Academy in Colorado Springs. His day started at 5:30 a.m. with a paper route; in junior high he was a member of the student advisory council, basketball team, track team, captain of his Andrews Air Force base bowling team and an honor roll student. When he got into high school the list lengthened.

"When I was working to get into an academy, I'd come home from school and get right into it. It was like school didn't end," he said.

Gest's hard work paid off in a big way: He has been offered appointments to all three of the major academies. The 18-year-old youth plans to accept the Air Force offer, following in the career footsteps of his father, an Air Force colonel.

The first letter came last December from the Naval Academy. The shy honor student from Surrattsville Senior High said he jumped up and down and yelled several times.

"Nobody has ever seen me that happy," said Gest, "because nobody was there."

Some 30,000 students applied to the three major service academies for the fall class of '81. Only about 4,800 will receive appointments and 4,000 will accept them. Twenty Prince George's students won appointments last year, according to a county schools spokesman. Only one was accepted by two of the academies.

Gest, whose family calls him Bobby, said the three academies are "all fine institutions but (the Air Force) what what I wanted to do when I get out -- flying," he said.

I thought about way down the line, about going to college, the funding for it and the type of job that would be in demand," he said. "I reached the conclusion that by going to a service academy, I would get one of the finest educations you could have and be guaranteed a job -- for the first four years at least."

He said he got his sense of what military life is like at his father's knee.

"When I was really young, I would sit in his office and listen to him talking with people about administration. And how many things go into making a decision. Especially when he was stationed at the Pentagon," he recalls."I could go around, walk into offices and see how things are done."

Gest earned a 4.16 grade point average last year, and the list of his scholastic, community and athetic accomplishments is two pages long.

His senior year is representative: member of the National Honor Society and the French Honor Society, Outstanding Defense Secretary at the Georgetown University Model United Nations, district finalist in the Voice of Democracy Eassy Contest, member of the Prince George's championship high school soccer team and the Andrews Air Force Base Bowling Team and named Young American of the Month for January by the Rotary Club of Southern Prince George's.

He also maintained a flawless four-year record delivering 70 Washington Posts before school each day and was statistician for the Friendly High School Girls Basketball Team.

How does he feel being called a "whiz kid?"

"I try to listen to it and keep on going," said Gest in an interview at his parents' well-furnished, split-level home in Clinton.He would not even read a recommendation a teacher handed him last year.

"She said, 'You're not going to read it?' I said no. I just wanted to keep that professional type relationship with her. I assumed that if she were going to write a letter of recommendation, she would say something nice," he said.

Gest was born in Guam in 1963. The military family followed father Robert III all over the country. Patricia Gest teaches business courses at Friendly Senior High School and devotes her non-classroom hours to her son's education and cultural development, and to that of his 11-year-old sister Roblyn.

Col. Gest, now stationed at the Pentagon, is between assignments. This fall he will move with his family once more, to Colorado Springs, where by a coincidence he will be inspector general at the Air Force Academy.

His mother, who has maintained meticulous records of her son's life in folders and scrapbooks, worries sometimes that he might be too different from most young men his age.

"His interests were not like . . . well, he was just different," his mother said. For instance, he built a model aqueduct system while he was in kindergarten.

By the time he was 12, Bobby weighed 150 pounds, and stood out among his schoolmates for his size as much as for his interests. Now a strapping 5-10, he has dropped from 238 pounds to 200 by lifting weights during the last few years.

"He just started wearing jeans in the 10th grade -- he was a real weirdo," his mother said affectionately.

With upper thighs almost the size of watermelons, he says it is tough to find jeans that fit anyway.

When he was in the fifth grade, the Gest discovered his adolescent passion -- war games. He still plays the increasingly sophisticated games, with a few friends who can appreciate the subtlety of what he calls "appropriate strategy."

"Since I was by myself a lot, I got interested in war games. I'd play both sides -- day and night," said Gest. There weren't very many other people interested in those things at my age."

Looking to the future, Gest said that politics would be a fitting end to a successful military career and, in his deliberate style, he already has begun thinking about strategy.

"Thinking about people like (Sen. John) Glenn, (Secretary of State Alexander) Haig, most of those people were of high rank or well known. I figure if I became an astronaut or obtain high rank that would help me politically, because more people would know the name," said Gest.

Recently, Gest had a first-hand glimpse of upper-echelon strategic decision making. He was voted Most Outstanding Defense Minister at this Year's Georgetown University Model United Nations Competition -- where teams of students act out authentic "scenarios" for international relations -- for his innovative and daring strategies for securing U.S. interests -- like the Gulf of Siam.

It would have been impolitic for U.S. warships to go directly to Thailand, he said, so he arranged for them to visit on "a diplomatic mission." But the Soviets decided to blockade the Gulf.

"Soon the Russian ships were seeing the Gulf of Siam from the underside," he said. The American ships made it to Bangkok, but, "We got a word of a Russian fleet steaming down from Vladivostock," said Gest. "It ended up a real free-for-all in the Gulf of Siam."

While he would rather it did not happen, Gest is not reluctant to move from playing war to serving in one.

"Look how many people in the world don't have this kind of freedom," he said. "I think it's the least I could do. For practically unrestrained freedom, it's a minor obligation."