This discussion paper relates to the principle of double jeopardy and whether there should be exceptions to it. ‘Double jeopardy’ is not a technical term of Scots law, and before embarking on a discussion of the principle of double jeopardy, it is important to define, at least in outline, what the term is understood to mean. According to the Oxford English Dictionary, ‘double jeopardy’ means ‘the placing of a person in jeopardy twice for the same offence, against which there is a common-law immunity’. It is possible to approach the question of when a person is twice placed in jeopardy in two ways. On one view, double jeopardy arises whenever there is a risk that an accused person will be subjected to more than one punishment for what is in substance the same offence. This understanding of the term has some currency in Scotland. This Discussion Paper is principally concerned with the other sense of double jeopardy, that is, with the rule or principle that a person once tried and convicted or acquitted of an offence should not be subject to further prosecution in relation to that offence. It is this to which is referred when we speak of the rule against double jeopardy. In part 2 of this Paper the principles and rationales underlying the rule against double jeopardy are considered. In Part 3, the present Scots law is examined. Part 4 contains a discussion of the international agreements relevant to double jeopardy. Part 5 introduces a number of options for reform. Part 6 considers a possible statutory restatement of the rule against double jeopardy, while Part 7 considers the case for the introduction of exceptions to that rule. Part 8 contains a list of the Commission’s proposals and questions. The Appendices contain detailed discussion of the European and human rights law relevant to double jeopardy and a summary of the law of double jeopardy in a number of other jurisdictions.