This Practice Note is produced in partnership with Síona Molony BL of the Bar of Ireland.What is a protective costs order?The purpose behind a protective costs order is to prevent litigants being precluded from bringing valid claims merely on the basis of the costs involved in doing so.A protective costs order is an order made by the court at an early stage of the proceedings guaranteeing that one party will not be liable for the other party’s costs (known as adverse costs), or that they will only be liable for a certain amount of those costs—regardless of the outcome of the case, subject to the terms of the order and any applicable statutory exceptions. This is unusual, because the order is granted by the court before the case concludes, and without the court having regard to the outcome of the proceedings. A protective costs order has very significant consequences for both parties to proceedings:•for the successful applicant, they are given the comfort that the risk of adverse costs