10.01 A deductible clause provides the maximum amount the insured must retain before he has a right of recovery under the relevant policy.1 A certain level of risk is hence left with the assured through the deductible or excess charges.2 Depending on the level of retained liability, the objective of a deductible is to encourage responsible behaviour on the part of the assured/reinsured or to relieve the insurer/reinsurer from having to respond to numerous low-value claims.3 Policy wording will determine how to calculate the assured’s retention. In the case of several separate incidents of damage, all flowing from one underlying cause, a “per loss” deductible may work to the serious disadvantage of the assured. Such an amount may be qualified by an aggregation clause, such as “per original cause,” which enables the assured to aggregate the retained losses together to exceed the deductible and give a right of recovery.