Animals are motivated to act so as to maximize their subjective reward rate, which depends on factors such as the subjective value and probability of a favorable outcome, the metabolic cost of action, as well as temporal variables such as deliberation and handling time. I’ll show mathematically that in a wide range of conditions, maximizing reward rates can be accomplished by having a criterion of decision accuracy that decreases over time as one deliberates. I’ll then present data from neural recordings in monkeys, suggesting that this is implemented in the brain through an “urgency signal” from the basal ganglia, which causes neural activity in sensorimotor decision circuits to build-up over time, pushing the system to decide while also influencing the vigor of the chosen action. Finally, I’ll review evidence suggesting how individual settings of urgency may explain traits such as impulsivity as well as motivation-related symptoms of clinical disorders such as depression and Parkinson’s disease.