This is a study of possession offences, with the focus on those intended to penalise the risk of a serious harm. Offences of this kind are examined in the light of basic doctrines of the criminal law, and in the light of the proper limits of endangerment offences. They are found wanting in both respects, and are also found to pose particular sentencing problems. The conclusion is that many risk-based possession offences are unfair, save those that require proof of a (...) further intent or those aimed at a failure properly to safeguard a dangerous object. (shrink)