For managing and settling ethnic conflicts, power-sharing arrangements often seem an appropriate solution. The former antagonists are forced to work together and make decisions by consensus; the ultimate goal is to turn opponents into partners. Obviously, this concept can only be successful under specific conditions and by specific arrangements. Based on a comparative analysis of six cases of power-sharing, the article aims (1) to identify favourable conditions as well as (2) to evaluate the quality of regulations. For successful conflict regulation, both aspects have to be taken into account: if the most favourable conditions are missing or will not be attained over time, then the 'best' power-sharing constitution will fail. If, in turn, 'bad' or insufficient rules and procedures prevail, then even the presence of comparatively beneficial factors will probably not avoid failure. Success will be understood as achievement and sustainability of a particular solution. The article is subdivided into four sections. First, the concept of power-sharing (or consociationalism) will be mapped out. Second, successful and failed European cases of power-sharing will be briefly presented. Third, by comparing these cases, the relevance of a set of conditions - usually assumed to be favourable for success - will be examined. Fourth, the quality of the institutional design of power-sharing regimes will be evaluated in order to distinguish 'better' regulations from more problematic or even counterproductive ones. In concluding, the author points to the crucial role of political elites in sustaining shared rule, but stresses at the same time that in most cases their behaviour is shaped by the institutional arrangements themselves. These have to be designed in a way that supports and fosters learning processes among decisionmakers.