The concept of desert (the principle that punishment should be made proportional to the severity of the crime committed) is introduced against its philosophical and legal background. Discussion focuses on the role of desert in contemporary sentencing reform proposals and the relationship between desert and other goals of legal punishment. Previous empirical research has addressed a between-offense conception of desert and suggests proportionality does control individuals' responses to crimes differing in severity. Our research focuses on the operation of desert within offenses (or the balance of harm done and punishment deserved for the individual offender) within the context of crimes of increasing severity. Six experimental simulations varied the relativity of victim/offender suffering prior to sentencing. Results show that for a minor crime punishment is an inverse monotonic function of offender suffering, but for crimes of moderate and high severity only excessive offender suffering successfully mitigated punishment. The source of offender suffering made no difference, supporting earlier work by Kalven and Zeisel; suffering exerted no effect on conviction decisions. Overall results are viewed as demonstrating the influence of both within- and between-offense conceptions of desert and the importance of the symbolic and moral blame components of legal punishment.