According to Orne (1951; 1959) reaI-simuIator differences in trance logic and duality reflect a trance state in hypnotics. The differential demands hypothesis, on the other hand, argues that real-simulator differences reflect the differential demands to which hypnotic and simulating subjects are exposed. Specifically, the differential demands hypothesis suggests that implicit demands for experiencing suggested effects and honest reporting to which hypnotics are exposed, lead these subjects to exhibit incomplete responses to suggestions. In contrast, simulators, who are not under demands to experience suggested effects or report honestly, simply follow their instructions by consistently enacting complete responses to even the most difficult suggestions. To test the hypothesis that reaI-simulator differences reflect incomplete responding to suggestions by hypnotics, groups of susceptible non-simulating hypnotic and imagination controls and groups of low and high-susceptibIe simulators were administered items tapping trance logic, incomplete responding, duality, and two hidden observer suggestions. Results were consistent with the differential demands hypothesis: Non-simulators reliably gave more incomplete responses than simulators. Trance logic items were found to discriminate between simulators and non-simulators only when these indicators also happened to tap incomplete responding. Furthermore, the two hidden observer effects failed to interecorrelate with one another or with the duality and trance logic items.