Consumers in Pennsylvania are entitled to bring suit for harm caused by a defectively designed product using one or both of these legal tests: "the consumer expectation test" (CET) or "the risk-benefit test" (RBT). Each test or definition of defect considered by a jury has its particular elements of proof and applying those elements to build your case can be daunting and expensive—because they are almost always expert witness dependent. To help understand and appreciate the steps required to develop and try a products case using the RBT, we provide this account of a recently litigated defectively designed helmet case.

The RBT provides that a product is in a defective condition if a "reasonable person" would conclude that the probability and seriousness of harm caused by the product (as sold) outweighs the burden or cost of taking precautions. This analysis accounts for the manufacturer's need to adopt precautions proportionate to the magnitude of the expected risk. The RBT provides for a post hoc opportunity to decide whether a manufacturer's conduct in manufacturing or designing a product was reasonable. This analysis is known as the "hindsight test." Courts applying the hindsight test note that a product is judged not by the conduct of the manufacturer or designer, but rather by the quality of the end result—the product is the focus of the inquiry. See Tincher v. Omega Flex, 104 A.3d 328, 391-403 (Pa. 2014). The quality of the product is measured not only by the information available to the manufacturer at the time of design, but also by the information available to the trier of fact at the time of trial. That test is articulated as follows: whether a reasonable manufacturer would continue to market his product in the same condition as he sold it to the plaintiff with knowledge of the likely dangerous consequences the trial has revealed. When a product manufacturer designs and markets some of its products with safety features which "… would probably protect … from serious injuries, it is itself strong evidence that the product … lacking such a device is defective …" Further, "this reflects the manufacturer's judgment that a vehicle … with the safety feature … will not be unduly expensive or inconvenient to use …" See Hammond v. International Harvester, 691 F.2d 646, 651 (3d Cir. 1982, PA law). If a defendant put a product that caused the plaintiff's harm into the stream of commerce and if that product was defective under one of the relevant rubrics, then the defendant is liable. See Roverano v. John Crane, 226 A.3d 526 (Pa. 2020).