Robert J. Rule began his lacrosse career as a goaltender at Manhasset (N.Y.) High School. The first lacrosse game he ever played in was the first game he ever saw. He played every minute of the game during high school, ending his career with an 84 percent save average and 2.17 goals allowed per game, and made All-Nassau County in 1967.

Rule continued his career in the nets at Cornell University where he was a member of the first NCAA Championship team in 1971. In 1971, he was elected First-Team All-American and First-Team All-Ivy. He was awarded the C. Markland Kelly Trophy as the nation's outstanding goalie and was selected to play in the North/South Collegiate All-Star game.

He played club lacrosse for Long Island in 1973 and 1974, and was a member of the 1974 U.S. team that won the World Championship in Australia.