Objective: This study protocol describes the RIGAB study, a prospective case-control-study assessing online sports betting behaviour and underlying risk factors for the development of gambling disorder (GD). It has two aims: (1) to characterise sports bettors concerning putative risk factors and their gambling behaviour, and (2) to predict the development of GD from these factors. Methods: At baseline, online sports bettors took part in an online survey comprising a GD screening (DSM-5), questions on gambling behaviour and on the putative risk factors emotion regulation, impulsivity, comorbidities, stress, and substance use. Participants were reinvited for a 1-year follow-up online survey. In a nested design, a subsample was invited in-person to take part in a cognitive-behavioural task battery and a clinical interview. Results: Of the initial 6568 online sports bettors invited, 607 participated at baseline (rate: 9.2%), 325 took part in the 1-year follow-up and 54 participated in the nested in-person assessment. Conclusion: The RIGAB study combines different fields of GD studies: player tracking data and putative risk factors from self-report and behavioural tasks. The results of this study will support the development of preventive measures for participants of online gambling based on the combined findings from previously rather distinct research fields.