Choice probability and choice response time data from a risky decision making task were compared with predictions made by a sequential sampling model. The behavioral data, consistent with the model, showed that participants were less likely to take an action as risk levels increase, and that time pressure did not have a uniform effect on probability choice. Under time pressure participants were more conservative at the lower risk levels, but were more risky at the higher levels of risk. This crossover interaction reflected that time pressure reduces the threshold amount of information within a single decision strategy rather than switching decision strategies. Response time data, as predicted by the model, showed that participants took more time to make a decision at the moderate risk levels, and that time pressure reduced response time across all risk levels, but particularly at the those risk levels that took longer time with no pressure. Finally, response time data were used to rule out the hypothesis that time pressure effects could be explained by a fast guess strategy.