The Raising Rivals' Costs theory is the newest and most important theory of non price predation. This dissertation assesses its ramifications for s. 36 of the Commerce Act 1986. Chapter I introduces the topic. Chapter II deals with non price predation and shows how it is an attractive strategy for dominant firms. Chapter III discusses the RRC model in depth. Chapter IV critiques it. Chapter V deals with the constituent elements of s. 36. Chapters VI to XIV deal with examples of prohibited conduct under s. 36. In each chapter I analyse whether the theory helps explain the cases, adds anything new and is relevant. I discuss U.S., Australian and New Zealand cases. Chapter XV concludes that the theory is relevant and useful under s. 36.