Русско-англо-русский юридический словарь

In order to be enforceable, a contract cannot violate "public policy". For example, if the subject matter of a contract is illegal, you cannot enforce the contract. A contract for the sale of illegal drugs, for example, violates public policy and is not enforceable. (expertlaw.com)

The object or subject matter of a contract must be legal. A contract for the sale of stolen vehicles will not be enforced by the court should there be a breach. (voicesofyouth.org)