Forensic assessments must always consider whether examinees are putting forth genuine effort or seeking to feign legally relevant incapacities. Miranda abilities are no exception when a putatively invalid Miranda waiver might result in the full suppression of an outright confession. Using a within-subjects simulation design, jail detainees were administered a representative Miranda warning and two Standardized Assessment of Miranda Abilities (SAMA) measures: Miranda Vocabulary Scale and Miranda Quiz. As expected, detainees have no difficulty in feigning severe deficits in their recall of the Miranda warning and portraying markedly impaired abilities on both SAMA measures. However, using floor-effect detection strategies, several feigning indicators proved effective at identifying likely feigned Miranda abilities. As an ancillary issue, the Inventory of Legal Knowledge was found to be very effective using both the traditional and revised scoring.