In the United States, the claims most commonly associated with product liability are negligence, strict liability, breach of warranty, and various consumer protection claims. The majority of product liability laws are determined at the state level and vary widely from state to state. Each type of product liability claim requires different elements to be proven to present a successful claim.

Types of liability
Section 2 of the Restatement (Third) of Torts: Products Liability distinguishes between three major types of product liability claims:

• manufacturing defect,
• design defect,
• a failure to warn (also known as marketing defects).

However, in most states, these are not legal claims in and of themselves, but are pleaded in terms of the theories mentioned above. For example, a plaintiff might plead negligent failure to warn or strict liability for defective design. Manufacturing defects are those that occur in the manufacturing process and usually involve poor-quality materials or shoddy workmanship. Design defects occur where the product design is inherently dangerous or useless (and hence defective) no matter how carefully manufactured; this may be demonstrated either by showing that the product fails to satisfy ordinary consumer expectations as to what constitutes a safe product, or that the risks of the product outweigh its benefits.

Consumer protection
In addition to the above common law claims, many states have enacted consumer protection statutes providing for specific remedies for a variety of product defects. Statutory remedies are often provided for defects which merely render the product unusable (and hence cause economic injury) but do not cause physical injury or damage to other property; the "economic loss rule" means that strict liability is generally unavailable for products that damage only themselves. The best known examples of consumer protection laws for product defects are lemon laws, which became widespread because automobiles are often an American citizen's second-largest investment after buying a home.