The use of e-scooters is rapidly increasing in cities, leading to their integration into the transportation system. However, numerous collisions involving e-scooters, including some resulting in fatalities, have been reported since their introduction. These incidents indicate that the potential dangers posed by e-scooters may be underestimated. Research suggests that a significant factor contributing to these collisions is the prevalence of illegal riding behaviour exhibited by many riders. This paper presents three studies that aimed to assess the understanding of e-scooter riders and non-riders of the current legislation across various riding scenarios and link it to their profile, riding habits, and their proneness to engage in illegal riding behaviours. Study 1 utilised questionnaires to survey participants and gather information about their profiles and self-reported illegal riding behaviour. Study 2 focused on assessing participants' knowledge of the current e-scooter legislation through different everyday riding scenarios. Study 3 featured short video clips from the rider's perspective to determine the proneness of participants to engage in illegal riding behaviour and explore the potential relationship between these behaviours and their understanding of e-scooter rules. The findings revealed that e-scooter riders were generally younger and exhibited a higher propensity for engaging in illegal riding behaviour than non-users. Both groups demonstrated limited knowledge regarding various aspects of the current e-scooter legislation, particularly related to parking, speeding, and designated infrastructure. While e-scooter riders demonstrated relatively greater knowledge of the e-scooter rules, this was not consistently observed across all areas, particularly in relation to riding on pavements (pedestrian footpaths). Furthermore, Study 3 revealed that participants with better knowledge of the current legislation were less likely to engage in illegal riding behaviour. These findings suggest a need for targeted interventions and educational campaigns to improve riders' understanding of regulations and promote safer riding practices. Implementing training programs for e-scooter safety could significantly enhance riders' awareness of the associated dangers, fostering responsible e-scooter use.