According to its simplest definition, supererogation means freely and intentionally doing good beyond the requirements of duty. A more complex definition incorporates the responses of third parties: the supererogatory act is one that is praiseworthy if performed, but not blameworthy if omitted, as long as one does one's duty. This collection of essays, based on papers delivered at the Royal Institute of Philosophy's Annual Conference in Dublin in June 2014, explores a broad range of philosophical problems that stem from various definitions of supererogation. How can something be good and yet not required? How relevant is the agent's motivation to our assessment of that agent's sacrifice? What is the difference between supererogation and virtue? Is supererogation essential to friendship and love? Do all of us have the genuine capacity to be saints and heroes?