Legality is not a requirement for a valid contract. The other three elements are essential for a contract to be valid.

A contract is illegal if it is against public policy, prohibited by statute, or contrary to good morals.

All of the above are examples of contracts that are illegal because they are against public policy.

All of the above are examples of contracts that are illegal because they are prohibited by statute.

All of the above are examples of contracts that are illegal because they are contrary to good morals.

An illegal contract is void, voidable, and unenforceable.

All of the above can challenge the validity of an illegal contract.

All of the above are remedies for an illegal contract.

The illegality doctrine serves all of these purposes.

Selling a kidney is illegal in most countries because it is against public policy and contrary to good morals.

The legality of gambling contracts depends on the laws of the jurisdiction in which the contract is made.

Prostitution is illegal in most countries, so a contract to work as a prostitute is also illegal.

Selling alcohol to a minor is illegal in most countries.

The legality of working without a license depends on the laws of the jurisdiction in which the work is performed.

Contracts that restrain trade are illegal in most countries because they are against public policy.