A (non-systematic) review of available literature reviews and recent research on high-stake, high-prize gaming machines and their relation to problem gambling. Aims to help the Gambling Commission to develop a programme of research for the future. Considers three areas: causal links between availability and the development of problem gambling; the attraction of these machines to existing problem gamblers and the exacerbation of gambling problems from access to such machines. Finds no general agreement about how much high-stake, high-prize gaming machines cause gamblers to become problem gamblers. Evidence suggested that there are associations between gaming machines and problem gambling, and that machine players were most likely to contact national telephone help lines. Evidence suggested that while gaming machines appeared to appeal to many gamblers, they seemed to be particularly attractive to those at risk of, or with a gambling problem. Compared to non-problem gamblers, problem gamblers tended to play on gaming machines more frequently, and spend more time and money on them. Certain features of gaming machines, such as fast games or offers of free games, appealed to gamblers and are therefore associated with higher levels of gambling and gambling-related harm. Research from some countries suggested that the accessibility of gaming machines has some association both with the level of gambling and with problem gambling rates, in particular local access. There was uncertainty in the available research about how best to minimise the harm that gamblers are exposed to when using gaming machines. The research suggested that to understand why most gamblers can enjoy using gaming machines without significant excess, but some seriously overspend and others become addicted, we need access to players in their gambling habitats and data on players. Both would need a substantial research effort as well as support from the industry.