Liability for defective systems arises in both criminal and civil law. There are no significant differences or exceptions to liability attaching to defective software within systems. The civil liability sets a higher bar than the criminal system: to put it another way if a manufacturer produces a product which is safe enough so as not to attract civil liability if it goes wrong, that manufacturer will certainly have no criminal liability if the product is nevertheless defective. Dai Davis, who is both a Chartered Engineer as well as a Solicitor will explain precisely what liability attaches to defective software and more importantly what a manufacturer or software author must do to ensure that a product (or the code) is “safe” from a legal perspective. He will explain in detail the civil legal wrong of Product Liability as well as looking briefly at the criminal law offences relevant to unsafe products. Finally, he will examine the issue of personal liability as opposed to corporate liability.