any insurance-related activities leading to the decrease of the size and frequency of losses. Material prevention means the activities financed by insurers aimed at decreasing the perils (e.g. social actions which may influence the number of accident to be lowered, construction of dams). Intangible prevention is more common and covers exclusion or reduction of liability in case of dangerous behaviors (e.g. willfulness, driving under the influence of alcohol, inadmissible passing), insurance recourse etc.