IEC 31010:2019 is published as a double logo standard with ISO and provides guidance on the selection and application of techniques for assessing risk in a wide range of situations. The techniques are used to assist in making decisions where there is uncertainty, to provide information about particular risks and as part of a process for managing risk. The document provides summaries of a range of techniques, with references to other documents where the techniques are described in more detail. This second edition cancels and replaces the first edition published in 2009. This edition constitutes a technical revision. This edition includes the following significant technical changes with respect to the previous edition: more detail is given on the process of planning, implementing, verifying and validating the use of the techniques; the number and range of application of the techniques has been increased; the concepts covered in ISO 31000 are no longer repeated in this standard.Keywords: uncertainty, risk management