When confronted with others’ fortunes and misfortunes, emotional reactions can take various forms—ranging from assimilative (happy-for-ness, sympathy) to contrastive emotions (envy, schadenfreude) and from prosocial (reward) to antisocial behavior (punish). We systematically tested how social comparisons shape reactions to others’ (mis)fortunes with a newly developed paradigm with which we investigated envy, happyfor- ness, schadenfreude, and sympathy in a joint rigorous experimental setup, along with individuals’ ensuing behavioral reactions. In nine experiments (Ntotal = 1,827), (a) participants’ rankings on a comparison dimension relative to other people and (b) others’ (mis)fortunes (changes in relative rankings) jointly determined how much individuals experienced the emotions. Upward comparisons increased envy and schadenfreude, and downward comparisons increased sympathy and happy-for-ness, relative to lateral comparisons. When the relevance of comparison standards (Experiment 4a) or the comparison domain (Experiment 4b) was low, or when participants did not have their own reference point for comparison (Experiment 4c), the effect of comparison direction on emotions was attenuated. Emotions also predicted the ensuing behavior: Envy and schadenfreude predicted less, whereas happy-for-ness and sympathy predicted more prosocial behavior (Experiments 5 and 6). Overall, the strongest social comparison effects occurred for envy and sympathy, followed by schadenfreude and happy-for-ness. The data suggest that envy and sympathy arise when comparative concerns are threatened, and happy-for-ness and schadenfreude arise when they are satisfied (because inequality increases vs. decreases, respectively) and predict behavior aimed at dealing with these concerns. We discuss implications for the function of fortunes-of-others emotions, social comparison theory, inequity aversion, and prospect theory.