The men -- one of whom was armed with a handgun -- entered the GameStop store at 522 Contra Costa Blvd. around 8:20 p.m. Tuesday and confronted two store clerks, according to police.
One of the men kicked open a storage room door as another controlled the two clerks and the third guarded the store's entryway, police said.
Police said the trio grabbed merchandise and a cashier's till, then fled and ran north through the parking lot toward Second Avenue South.
One suspect is described as a black man with a light complexion between 25 and 29 years old, standing over 6 feet tall with short black hair and blue eyes.
Another suspect is described as a Pacific Islander man in his early 20s around 6 feet tall with black hair weighing about 210 to 220 pounds.
Anyone with information about the crime is asked to contact the Pleasant Hill Police Department's investigations division at (925) 288-4630.