There are a significant number of different arbitral institutions, arbitral organisations and arbitration rules, and the distinctions between them are not always obvious. The tables below contain information comparing some key provisions of some of the most commonly used international arbitration rules. For detailed guidance on key sets of arbitration rules, the Overview documents in the ‘Related documents’ provide a helpful starting point. For an explanation of the key differences between institutional arbitration and ad hoc arbitration, see Practice Notes: Institutional arbitration—an introduction to the key features of institutional arbitration and Ad hoc arbitration—an introduction to the key features of ad hoc arbitration. Choosing arbitration rules Parties that choose arbitration over litigation will rarely agree their own procedural rules governing their arbitration proceedings, although they are entitled to do so given that arbitration is a consensual process. Instead, they will often agree to use the arbitration rules of an arbitral institution or other organisation, modified as appropriate to suit their own requirements. Parties can agree to have their arbitration