Rule began his lacrosse career as a goaltender at Manhasset (N.Y.) High. The first lacrosse game he ever played in was the first game he ever saw. He ended 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. He was also selected as a first team All-American and first team All-Ivy player that year, and was awarded the C. Markland Kelly Trophy as the nation's outstanding goalie. Rule also played in the North/South Collegiate All-Star game.
After Cornell, Rule 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. He also returned to Manhasset in 1974 to teach history and help coach boys’ lacrosse at his alma mater. Working first as an assistant under fellow Hall of Famer Alan Lowe, and then with his successor, Bill Cherry, Rule helped Manhasset reach seven state championship games and win four titles, while also racking up several Nassau County and Long Island crowns. Rule retired in 2014 following a 40-year coaching and teaching career.
In addition to his membership in the National Lacrosse Hall of Fame, Rule was inducted into the Cornell Athletics Hall of Fame in 1986, the Long Island Metro Chapter Hall of Fame in 1988, and the Manhasset Lacrosse Hall of Fame in 1991. Bob Rule passed away in November, 2022, He was 73 years old.