In this chapter, Christian Barry and Holly Lawford-Smith take up the question of whether there comes a point at which one is no longer morally obliged to do further good, even at very low cost to oneself. More specifically, they ask: under precisely what conditions is it plausible to say that that “point” has been reached? A crude account might focus only on, say, the amount of good the agent has already done, but a moment’s reflection shows that this is indeed too crude. Barry and Lawford-Smith develop and defend a nuanced account according to which considerations of three types are all relevant to whether one has satisfied one’s duties to assist: “inputs” (types and quantities of sacrifice made), “characteristics” (the beliefs and intentions that informed the donor’s decisions), and “success” (the extent to which the donations in question succeeded in generating value).