This chapter addresses assessment of feigning or exaggeration in cases involving claimed amnesia for the crime, in intellectually disabled defendants, and in adolescent examinees. Claimed amnesia for the offense is one of the most common forms of feigning in criminal defendants, and multiple tests, including the crime-specific symptom validity test, as well as self-report measures and traditional validity tests, permit assessment of claimed memory problems. Intellectually disabled defendants, whose reading or verbal ability may compromise self-report measures and even structured interviews, present multiple challenges for validity assessment. Further, many performance validity tests are vulnerable to false positives for such examinees and cannot distinguish low ability from poor effort. This chapter suggests ways in which collateral data, such as prior IQ scores, can help inform the competency judgment. Finally, adolescent defendants present difficulty because much less research has been conducted on response style in non-adults. The available data are reviewed and suggestions are offered.