Art. 1306. The contracting parties may establish such stipulations, clauses, terms and conditions as they may deem convenient, provided they are not contrary to law, morals, good customs, public order, or public policy.
Art. 1347. All things which are not outside the commerce of men, including future things, may be the object of a contract. All rights which are not intransmissible may also be the object of contracts. No contract may be entered into upon future inheritance except in cases expressly authorized by law. All services which are not contrary to law, morals, good customs, public order or public policy may likewise be the object of a contract.
Art. 1409.The following contracts are inexistent and void from the beginning: (1) Those whose cause, object or purpose is contrary to law, morals, good customs, public order or public policy; (2) Those which are absolutely simulated or fictitious; (3) Those whose cause or object did not exist at the time of the transaction; (4) Those whose object is outside the commerce of men; (5) Those which contemplate an impossible service; (6) Those where the intention of the parties relative to the principal object of the contract cannot be ascertained; (7) Those expressly prohibited or declared void by law. These contracts cannot be ratified. Neither can the right to set up the defense of illegality be waived.
Art. 1411. When the nullity proceeds from the illegality of the cause or object of the contract, and the act constitutes a criminal offense, both parties being in pari delicto, they shall have no action against each other, and both shall be prosecuted. Moreover, the provisions of the Penal Code relative to the disposal of effects or instruments of a crime shall be applicable to the things or the price of the contract. This rule shall be applicable when only one of the parties is guilty; but the innocent one may claim what he has given, and shall not be bound to comply with his promise
Art. 1416. When the agreement is not illegal per se but is merely prohibited, and the prohibition by the law is designated for the protection of the plaintiff, he may, if public policy is thereby enhanced, recover what he has paid or delivered.