Rivalry is prevalent across many competitive environments and differs in important ways from non-rival competition. Here, we draw upon research on relational schemas and automatic goals to explore whether mere exposure to or recall of a rival can be sufficient to increase individuals' Machiavellianism and unethical behavior, even in contexts where their rivals are not present. Across four experiments, we found that activation of the rivalry relational schema led to increased Machiavellianism (Experiments 1 and 2), false inflation of performance (Experiment 3), and deception of an online counterpart for self-gain (Experiment 4). In Experiment 4 we also observed an interaction between rivalry and moral identity such that when the rivalry relational schema was activated, moral identity no longer safeguarded against unethical behavior. This finding suggests that a rivalry mindset crowds out moral identity as a guide to behavior. Overall, the current research depicts rivalry as an important relationship that activates a unique mindset and has a more widespread influence on behavior than prior research has suggested.