【Abstract】  The current work explores how tool anthropomorphism adversely affects people’s rewards for tool users. This effect arises because tool anthropomorphism decreases perceived effort of tool users as people see tool users to be exerting less effort with some of the effort picked up by the anthropomorphized tools. Study 1 adopts a context of a national city-cleaning activity to verify the main effect in the form of prosocial behaviors. Study 2 replicates the main effect in a consumption context for monetary reward (i.e., tips). Study 3 reveals the underlying mechanism of perceived effort and rules out the alternative explanation of perspective-taking. Study 4 verifies the mediating role of perceived effort by manipulating tool users’ effort as explicitly mentioned (or not). Finally, Study 5 shows the moderating role of just world belief. Our findings are robust across various contexts and provide novel theoretical and practical implications.