Based on a relevant literature review, the author projects that pathological gamblers will cluster into two or possibly three types. In a three-type scenario, a "normal" problem gambler emerges. This type has periodic gambling problems, arguments with significant others, and moderate financial difficulties; however, this type only rarely engages in illegal activity and only rarely comes into contact with the criminal justice system. A second type is the "recurringly depressed gambler." This type gambles to escape from emotionally disturbing experiences that range from chronic loneliness to severe trauma. The third type of pathological gambler has been called the "chronically understimulated" gambler. This is the action seeker and biologically based impulsive type who gambles for the thrill and risk of the action. Studies conducted among inmates or among substance abusers will tend to find more of the impulsive action seekers than escape seekers and probably no "normal" problem gambler types. Research on pathological gambling has numerous parallels with research into substance abuse. The types of pathological gamblers have parallels with types of alcoholics and cocaine addicts. Further, Potenza and colleagues found a strong association between problematic lottery gambling and illegal activity. They note that problematic lottery gambling may be conducive to illegal behavior. It is possible, however, that rather than lottery gambling alone, impulsivity and the desire to be in action on many fronts at the same time may be the explanation behind the lottery and crime connection. Additional research might compare problem gamblers who only gamble on lotteries and those who engage in problematic lottery gambling in combination with other forms of gambling. 30 references