Legal Question in Business Law in California

It depends. Some laws can be waived via contract, and some cannot.

As Mr. Haddock says sometimes yes, sometimes no. It primarily depends on the nature of the law that the contract would supersede - actually it's a waiver of a right or the protection one party to the contract would normally enjoy under the law. In general, laws enacted to protect a certain class of persons, or the public at large, from certain types of behavior may not be waived in a contract. Many consumer protection laws fall in this category. Such waivers, even if included in the contract language, are void as against public policy.

In some ways, yes. In other ways, no. A contract to do something illegal is void and unenforceable. A contract which obligates one or more of the parties to waive some of their rights or that excuses others from some of their duties (to the other party or parties) will usually be valid. Without knowing anything about the specific contract you have in mind, that's the best I can do.

Here's an example. California's version of the Revised Uniform Partnership Act ("RUPA") is codified in the Corporations Code as sections 16100 to 16962. Section 16401(h) says a partner is not entitled to remuneration for services rendered to the partnership, and as a consequence, a disgruntled partner cannot go to the labor commissioner and file and win a complaint for minimum wage, overtime, etc. for tending the store. However, Section 16103 gives the partners authority to modify all but a few of the more general rules govering the relationship of the partners to each other, and to the partnership by contract. The contract can be written, oral, or implied from the partners' conduct. If a pay-for-services provision exists in the partnership agreement (or any amendment to it), the partner become entitled to pay per the agreement.

Another simple example. The Civil Code says trees whose trunks stand on the property line belong equally to the neighbors. I see no reason why Neighbor X and Neighbor Y could not, by contract, assign the odd-numbered trees to X and the even-numbered trees to Y.

When called upon to decide whether a law's effect can be modified, waived or nullified by private agreement, a court would have to consider the purpose of the law (the intent of the legislature in passing it), whether it was meant to protect or direct the parties involved or is directed at someone else, and the language of the law -- is it declaratory, mandatory, permissive; does it mention "illegal" or "unlawful" and so on.