Considering collision events during design has long been a standard practice in both ship and offshore design. Collision events are herein considered as Accidental Limit State (ALS) loads with an annual probability of exceedance of less than 10−4. How these events are considered is a matter of considerable variation. For ships, the traditional method has been to consider the robustness of the damage stability of the vessel in terms of certain prescribed damage zones, e.g., 20% indentation of the vessel beam. For the damage stability of offshore structures, the actual extent of damage and the residual strength after the collision should typically be considered, though minimum prescriptive requirements still apply. In addition, unique design challenges related to specific hazards, such as oil and LNG tanks, hazardous cargo etc. should be considered for all types of marine structures.