Risk is always associated with a decision, and doing nothing is one of them. However, when dealing with disaster risk, doing nothing is not an efficient choice. Even if we do not all agree on what should be an acceptable risk level, we can admit that current levels are evidently unsustainable. A major limitation for mainstreaming investments in DRR is its lack of understanding and robust assessments. This presentation will explore quantitative ways to assess disaster risk for baseline and future scenarios, from which risk reduction and resilience targets can be set, and for which the benefits and costs of a set of activities (i.e., strategies) can be evaluated. The goal is to ensure that DRR investments and measures are informed by evidence and are robust under unknown future outcomes.