Gamers with poor self-concept, high social anxiety and high loneliness are more at risk of problematic involvement in video games, such as massively multiplayer online role-playing games. There is a research gap concerning treatment approaches to cater to socially anxious gamers with problematic patterns of gaming involvement. This registered exploratory pilot programme tests the feasibility and initial effect of a structured protocol in which socially anxious online gamers are exposed to real-life social interactions while playing an offline tabletop role-playing game (TTRPG). Our structured protocol lasted 10 weeks and involved 10 sessions organized into three modules in which participants played a TTRPG inspired by the game ‘Dungeons and Dragons’. Each module deployed a role-playing scenario designed to challenge the players in game terms and involve them in a story based on maturing relationships with other characters and solving challenges by social means and investigation. Our study used a quasi-experimental multiple single-case design with a three-week baseline across groups (four groups of five gamers with sub-clinical problematic video game use and social anxiety) and a three-month follow-up. Primary outcomes were time spent gaming, gaming disorder symptoms and social anxiety symptoms. Secondary outcomes were assertiveness/social skills, self-concepts and perceived loneliness. In terms of feasibility, we observed that most participants completed the programme (two of the 20 participants dropped out) and were involved in terms of participation and weekly psychometric assessments. Moreover, participants were largely able to attain the progressively more difficult objectives implemented in the TTRPG programme. Multiple single-case analyses showed that most participants benefited from the intervention through a reduction in social anxiety symptoms and problematic gaming symptoms, although to varying degrees. Some participants also reduced their gaming time or presented with reduced perceived loneliness. Assertiveness and self-concepts were not improved. This pilot study shows that a TTRPG intervention approach is feasible and may be used to reduce social anxiety and gaming disorder symptoms. The present programme must now be tested with clinical participants.