This paper explores the Offence Principle. It discusses whether two constraints, additional to the criteria stated in conventional analysis, ought to be met before the Offense Principle can be satisfied: (i) that offensive conduct must be a wrong, and (ii) that the conduct must also lead to harm. The nature of the Harm Principle, and its relationship to the Offense Principle, are also considered. The paper suggests that, even if all cases in which offense should be criminalized also involve harm, nonetheless there may be good reasons to retain a separate Offense Principle.