Shared leadership is becoming increasingly important today, yet it still represents a counterpoint to established hierarchical leadership models. Through a multimethod approach, Simon Werther investigates how shared leadership relates to effectiveness. Based on an interview study with 30 leaders, he identifies individual (e.g., conflict competence), interpersonal (e.g., competitive mindset), and organizational (e.g., time resources) influencing factors. At the same time, the author demonstrates that shared leadership is already widespread in practice and can be successfully combined with hierarchical leadership. In a questionnaire study, he examines the impact of positive conflict management. From the results of all studies, he derives significant implications for leadership practice.