In a reconsideration of the achievement-motivation theory it is assumed that moderate stimulation releases positive affects and very low or high stimulation negative affects. It is further assumed that as far as the achievement-motivation system is concerned the most stimulating situation is that where the probability of success (Ps) is about .50, the least stimulating that where Ps is near 1.00 or .00. The motive to achieve success (Ms) and the motive to avoid failure (Mf) are thought of as moderators of the stimulation provided by a given situation. Ms-dominated individuals should experience positive affects (moderate stimulation) where Ps is about .50 and should therefore engage in such situations. Ps near 1.00 or .00 implies very low stimulation; hence, negative affects should be released, resulting in resistance to such situations. Mf-dominated individuals should experience negative affects (very high stimulation) where Ps is about .50, while they should experience moderate stimulation, and thus positive affects, if at any point, only where Ps is either very high or very low. This implies that the relationship between Ms strength, respectively Mf strength, and degree of engagement should vary from positive to negative, depending on the probability of success in the situation. Results from previous investigations are related to these viewpoints.