This thesis extends current research on Persuasive Systems Design (PSD) to recreational gambling. As online gambling carries a greater risk for the development of gambling addiction pathology than offline gambling, examination of how to create effective tools that can reduce this risk are warranted. One such area is usability and PSD, with the goal of aiding individuals to adhere to pre-set monetary limits without reducing the pleasure of gambling. A user-centred design process was employed to improve an existing monetary limit tool with the goal of facilitating responsible gambling. Focus
groups, personas and storyboards and heuristic evaluation were employed to design the monetary limit tool, and a controlled lab study was carried out to test the effectiveness of the newly developed tool. Results of the study show that applying usability and PSD principles increased monetary limit adherence and engagement, and the monetary limit tool did not interfere with users’ fun.