It's (Not) Just a Game (1998)

Kathy can't wait to participate in a role-playing game with her boyfriend. When she and her co-worker are confronted in the office late at night, she believes the "thug" has been hired by her lover. Unfortunately for the damsels-in-distress, this isn't the case and when the bad guy doesn't get the answers he wants, he leaves the bound and gagged office workers with dynamite attached to a very real timer.