Many teams struggle with the discussion of acceptance criteria of user stories and building a shared understanding about the expected outcomes. This leads to unfulfilled implicit expectations of stakeholders, ad-hoc assumptions of the team during implementation and frictions between development and testing in a cross-functional team. Efforts for regression testing and the lack of a reliable source of truth about the currently expected system behavior are additional pains emerging from a weak practice for agreeing on and validating acceptance criteria. In this session Christian will show how specification-by-example and acceptance test driven development can help to address previously described challenges and problems. The presentation will cover theory as well as examples and practical experience from own projects.