The present study investigated the relationship between personality and task dimensions of perceived locus of control. Male alcoholic subjects were administered Rotter's I-E scale and participated in both chance and skill tasks with expectancies for future success used as dependent variables. A series of complex interactions were obtained in which internal and external subjects provided differential levels of expectancy shifts as a function of both the nature of the task (chance or skill) and their success or failure on each. These interaction effects were discussed in terms of differential levels of motivation for internals and externals within change and skill tasks.