An attempt to contract for an illegal purpose—to commit a murder or other crime or to facilitate an illegal objective (a promissory note for the purchase of illegal drugs)—is unenforceable and does not create a contract. A purported contract that is found to be for an illegal purpose is void and treated as if it never existed.
In California, as in all states, a contract must have a lawful object to be enforceable. If a contract is formed with the intent to commit a crime, such as murder, or to facilitate an illegal objective, such as the purchase of illegal drugs, it is considered void from the outset. This means that the contract has no legal effect and is treated as if it never existed. California law, consistent with general contract principles, does not recognize any agreement that involves illegal activities as a valid contract. Therefore, any attempt to enforce such a contract in a court of law would fail, as courts will not enforce agreements that are contrary to public policy or that involve committing a criminal act.