Example-based learning is a well-known instructional method for effective cognitive skill acquisition in complex domains. "(Contrasting) erroneous examples" are a promising extension that embed errors in instructional material, potentially fostering not only positive but negative knowledge. However, the mechanisms and conditions for their effectiveness remain unclear. This systematic review synthesized findings from 40 studies across disciplines to examine how influential factors affect the effectiveness of "(contrasting) erroneous examples." Results show that these examples can enhance learning, but their benefits depend on how errors are explained or highlighted, how prompts are designed, and on learners' prior knowledge and cognitive capabilities. While erroneous examples appear similarly effective across comparison groups, contrasting erroneous examples are more often effective than correct examples and problem-solving and are sometimes equally or even more effective than erroneous examples. While prompts that require learners to identify, explain, correct, or reflect on errors often promote deeper learning, they may also shift the balance from productive engagement toward cognitive overload, particularly when the material is complex. Evidence on prior knowledge, cognitive load, and long-term effects appears to be contradictory, especially in the comparison between "contrasting erroneous examples" and "erroneous examples." Our review highlights the need for further empirical research to determine how these factors must be balanced to maximize learning benefits and to clarify under which conditions "(contrasting) erroneous examples" are most effective.