Brian Blume was born January 12, 1950 in Chicago, Illinois. Blume began began playing chess at age seven, and Gettysburg from Avalon Hill in 1959. He was fascinated by history in junior high school, and got involved in miniature wargaming in high school. Blume was married, but later divorced. He worked as a tool and die maker's apprentice.

Blume met Gary Gygax at the Gen Con game convention in Lake Geneva, Wisconsin, and later partnered with Gygax and Don Kaye in the TSR enterprise in 1974, with his father Melvin Blume providing the funding to publish the original Dungeons & Dragons boxed set. After the death of Kaye in 1976, his widow sold her shares to Gygax. Gygax, now controlling the whole of Tactical Studies Rules, created TSR Hobbies, Inc. with himself as company president. Gygax, coming into financial troubles soon after, sold TSR Hobbies to Brian Blume and his brother Kevin, whom Brian got nominated to TSR's board. The Blume family would own roughly two-thirds of TSR Hobbies by late 1976.

Blume authored the Dungeons & Dragons supplement Eldritch Wizardry with Gygax in 1976, naming the character Vecna as an anagram of Jack Vance, and also worked on the supplement Swords & Spells with Gygax. Blume also worked on The Rogues Gallery. With Gygax, Blume also co-authored the Warriors of Mars miniatures wargame adaptation in 1974, and the Boot Hill role-playing game in 1975. Blume also authored the Panzer Warfare miniatures wargame in 1975.

The Blumes brought in three outside directors from the AMA to increase the Board of Directors to six: a lawyer from a large Milwaukee firm, a personnel officer from a Milwaukee area company, and an owner of a company that made medical equipment, none of whom knew anything about gaming but always voted with the Blumes.

While Gygax was involved in the making of the Dungeons & Dragons animated television show and exploring the possibility of a film adaptation of the game, he left the day-to-day operations of TSR to his fellow board members, Kevin and Brian Blume. By the time he came back to Wisconsin, the company was $1.5 million in debt. In response, Gygax persuaded the board of directors to fire Kevin Blume. Gygax persuaded Lorraine Williams to invest in TSR, and hired her to manage the company. Williams dismissed the three outside directors, who had been in place for about two years by that time. The Blumes soon sold their stock to Williams, removing Gygax's controlling stake in the company. Brian Blume left TSR after a bitter struggle with Gary Gygax. Gygax sold his remaining stock and left TSR in 1985.

Blume later worked as a cartographer, mostly on numerous White Wolf supplements.