The study measured responsible gambling (RG) beliefs and behaviors among a sample of people who reported betting on an online sports wagering site and/or reported gambling at a physical casino in Massachusetts (MA) during the previous six months. The goal was to generate insights to better promote positive, healthy play in the state. Important to note is that the survey captured the experiences of highly engaged MA gamblers rather than a cross-section of the general population of players. Most respondents reported high levels of belief in taking ownership of gambling behavior, honesty with others about their gambling behavior, and feeling in control of their behavior, while pre-commitment behaviors were more mixed. Gambling literacy was the lowest-scoring area, indicating widespread misconceptions about key gambling concepts such as randomness, independence of events, and the role of chance.