Abstract: Unlike “Intentional Torts,” “Negligence,” and “Strict Liability,” “Recklessness” is not the name of a tort category. However, it does make sporadic appearances in tort law, often in cases that seem to fall between established categories; in this sense, it operates interstitially within the field. In fact, recklessness plays this role in two very different ways. In the law of defamation and fraud, it amounts to something less than full-fledged knowledge of falsity but more than negligence or even gross negligence, thus setting the lower boundary of malice. In other tort settings—including the application of certain assumption-of-risk doctrines—it again involves more than negligence, but less than full-fledged intentionality, but here it sets an upper boundary for negligence, namely, the point at which conduct becomes so unjustifiably dangerous that no-liability arguments that are viable in response to ordinary negligent conduct lose their force. We contend that attention to the ways in which recklessness serves as a fine-tuning mechanism in tort law can illuminate philosophical debates about the nature of recklessness, as well as jurisprudential inquiries concerning interstitial legal concepts.