David Arneson, one of the masterminds who created the original version of the award-winning fantasy game Dungeons & Dragons, died Tuesday in St. Paul following a two-year battle with cancer.

Arneson, 61, teamed up with co-creator Gary Gygax in 1974 to create Dungeons & Dragons, which remains one of the best-known and biggest-selling role playing games of all time. An estimated 20 million people have played the game, in which players create characters who embark on imaginary adventures within a fantasy setting. Characters solve dilemmas, engage in battles and gather treasure and knowledge, and in the process earn points to become increasingly powerful over a series of sessions.

The game became wildly popular with wargamers at its debut and soon after became a favorite of high school and college students. Since its debut, several editions of the game have been released, and it has been turned into an animated television series, movies, computer games and inspired a host of other role-playing games.

As a University of Minnesota history student in the late 1960s, Arneson developed an interest in naval war games and recreating battles complete with miniature armies and fleets. He had begun to design Blackmoor, a role-playing game that involved medieval miniatures exploring the dungeons of a castle inhabited by monsters, when he attended GenCon in 1969, said Wizards of the Coast, the subsidiary of Hasbro, Inc. that produces the game. That is where he met Gygax. Along with Jeff Perren they collaborated to create a game of sailing-ship battles called Don't Give Up the Ship. They swapped ideas and came up with the script that eventually led to Dungeons & Dragons.

"He developed many of the fundamental ideas of role-playing: that each player controls just one hero, the heroes gain power through adventures and that personality is as important as combat prowess," according to a statement released by Wizards of the Coast. "His Blackmoor was the first-ever role-playing campaign and the prototype for all role-playing campaigns since. All of us in the industry and hobby owe a great debt of thanks to Dave Arneson and his ground-breaking Blackmoor game."

In his later years, the St. Paul Central High School graduate published other role-playing games, including Adventures in Fantasy, and started his own game-publishing company (Adventure Games) and a computer game company. He also taught classes in game design. Arneson was inducted into the Academy of Adventure Gaming Arts and Design's Hall of Fame in 1984. Pyramid magazine named him one of "The Millennium's Most Influential Persons."

In an e-mail statement released by his family shortly after his death, his daughter, Malia Weinhagen, said, "the biggest thing about my dad's world is he wanted people to have fun in life. I think we get distracted by the everyday things you have to do in life, and we forget to enjoy life and have fun."

In addition to his daughter, Malia, of Maplewood, Arneson is survived by his father, John, of St. Paul, and two grandchildren.

A memorial service will be held at 11 a.m. April 21 at Immanuel Lutheran Church, 104 S. Snelling Av., St. Paul. Visitation will be held from 4 to 8 p.m. April 20 at Bradshaw Funeral Home, 687 S. Snelling Av., St. Paul.