Products liability law controls the private litigation of products accidents which provides compensation to the injured party. Products liability law involves the tort law of negligence or strict liability and the contract law of sales or warranty. The liability may arise as a result of a defect in design or manufacturing improper service breach of warranty or negligence in marketing due to improper directions warnings or advertising.In all products liability suits the plaintiff must prove causation. The plaintiff must prove that the product was substantially responsible for her injury. This can be done by proving that it is more probable than not 51% likely that the product caused the injury.The doctrine of strict liability provides that one who sells a product in defective condition that is unreasonably dangerous to a consumer is liable for harm caused to the user or the user property. The focus in a strict liability suit is whether the product is defective and not whether the manufacturers conduct was careless. Under the doctrine of strict liability the injured party must prove that the product was defective and unreasonably dangerous the defect was present at the time of manufacture and the defect caused the injury. In addition almost all courts require the injured party to prove that a safer alternative design was available at the time of manufacture.Whether the product is considered defective is one of the central issues in any products liability case. A manufacturing defect can easily be proved merely by comparing a defective product to a non defective one by the same manufacturer.