The responsibilities which civil engineers, and particularly the engineer of record, accept are considered. The interaction with other decision-makers such as the owner, stakeholders, the law and contractors results in complexity that can be partially resolved by the introduction of protocols in the form of regulations and codes of practice. However, uncertainty always exists and can result in surprises that can produce both beneficial and bad results. The sections entitled the cast, protocols and reality, advocacy and surprise, and complexity cover these topics. The nature of responsibility is analysed. Professional engineers work within an increasingly complex environment and have a responsibility to acquire and use skills beyond those applicable to traditional technical issues.