Roman law classified obligations into four main categories: 1) Obligations from contract - These included real contracts (formed by transfer of an object), verbal contracts (formed through spoken agreement), literal contracts (formed through a written document), and consensual contracts (formed through mutual consent). 2) Obligations from delict - These arose from wrongful acts like theft or damage to property. 3) Obligations from quasi-contract - These were obligations imposed by law without agreement, such as those arising from unjust enrichment. 4) Obligations from quasi-delict - These were similar to delicts but involved negligence rather than intentional misconduct. For a contract to be valid under Roman law,