Research on learning from errors gives reason to assume that errors provide a high potential to facilitate deep learning if students are willing and able to take these learning opportunities. The first aim of this study was to analyse whether beliefs about errors as learning opportunities can be theoretically and empirically distinguished from adaptive reactions to errors in an affective-motivational sense (including the maintenance of motivation and activating emotions), and in terms of learning behaviour and metacognitive activities specifically adjusted in response to a specific error. The second aim was to validate the proposed distinction across different domains. The third aim was to investigate the added value of beliefs about errors besides domain-specific self-concept and mastery goal orientation for understanding the preconditions for adaptive reactions to errors at school. We assessed all variables in three different school subjects (N = 614 students, Grades 5-7). Confirmatory factor analyses indicated distinctness and a moderate domain specificity of error-related reactions. Positive error-related beliefs predicted students' affective-motivational and action adaptivity of error reactions, above and beyond self-concepts and goal orientations. Taken together, the current findings provide a more complete understanding of the intra-personal mechanisms of adaptive responses to errors in different school subjects.