To investigate the neural substrates of risky decision making in gambling tasks, we recorded event-related potentials while participants engaged in a modified blackjack game. We focused on the high-conflict condition (probability of losing approximately 50%) and low-conflict condition (probability of losing approximately 20%). We were also interested in the difference between risky and conservative responses under high-conflict conditions. In the 220-320 and 500-600 ms time windows, high-conflict conditions elicited more negative event-related potential deflections than low-conflict conditions. In the latter time window, risky conditions elicited more negative event-related potential deflections than conservative conditions. The N2 (220-320 ms) and N500 (500-600 ms) provide evidence for the dissociation of neural circuits between perceptual and response conflicts.