In 2015, the Norwegian Petroleum Safety Authority introduced a new definition of risk, formulated as ‘…the consequences of activities with associated uncertainty.’ This paper explores how the new definition is understood in the industry and possible changes in risk management the change has led to in the Norwegian petroleum industry. Semi-structured interviews with seven operational decision-makers from operator companies in Norway were conducted to gain insight into their understanding of the new concept, and its implementation Decisions were primarily based on available knowledge, including tools, analyses, industry experience, and joint assessments with experts. Sources of uncertainty highlighted by the informants included new technology, a lack of competence and knowledge, and external factors such as pandemics and global conflicts. Implementing the new concept of risk has increased awareness of the uncertainty dimension of risk and has led to the adoption of new tools and assessments. However, there is a need for further development of tools and methods to address the uncertainty dimension of risk across companies and actors. The study highlights the importance of communication and discussion between decision-makers and knowledgeable personnel for dynamic and effective risk management, and a shared understanding of risk is necessary for managing it effectively.