Literature on ‘law and peace’ has grown substantially. One of the explanations may be the flexible way in which the concept ‘law’ has been used. This entry for the forthcoming Elgar Concise Encyclopedia on Law and Peace, edited by Louise Mallinder, Rachel Killean and Lauren Dempster, uses five bodies of scholarly work on ‘law and peace’ to illustrate divergences in the conceptualisation of ‘law’. It argues that when reading the literature on ‘law and peace’, it is important to ask the question ‘law, in what sense?’