Abstract: “Intentional torts,” “Negligence,” and “Strict Liability” are typically cast as the major categories of tort liability. Conspicuously absent from this list is “Recklessness,” which would seem to fit between intentionality and negligence and is treated in criminal law as a category of its own. And yet recklessness does make sporadic appearances in tort law. Because it lies between categories without constituting a distinct category, recklessness thus can fairly be described as operating “interstitially” within tort law. As we explain, recklessness fulfills this role in two quite different ways. In the law of defamation and fraud, it sets the lower boundary of ‘malice,’ understood as mistreatment of another involving dishonesty or other states of mind inconsistent with good faith. A quite different collection of tort settings in which recklessness plays an important role – one that includes the application of assumption of risk to recreational activities – are those in which courts are prepared to relieve actors of liability notwithstanding that their actions generate a significant risk of harm. In this domain, recklessness marks an upper rather than a lower boundary, namely, the point at which conduct becomes so unjustifiably dangerous that liability will attach. We conclude by suggesting that attention to the different ways in which recklessness serves as a fine-tuning mechanism in tort law may illuminate philosophical debates about the nature of recklessness, as well as jurisprudential inquiries concerning interstitial legal concepts.