Internal conflicts of laws may be defined as conflicts arising from the coexistence within a state of laws specific to different areas of the country (interlocal conflicts) or of laws specific to different categories of individuals based on their membership in a particular community (interpersonal conflicts). Analyzing these conflicts is of undeniable practical importance: most states are, or were at one time, plurilegislative. It is also of great theoretical interest from an interdisciplinary perspective. Filling the gap left by the lack of a comprehensive study of internal conflicts, this article explores numerous non-unified legal systems and suggests an innovative way to treat them all the same way. After identifying the features of internal conflicts by demonstrating their similarities with international conflicts, it reviews the traditional categories and suggests a new way of resolving internal conflicts, either by courts in the plurilegislative states directly concerned or by foreign courts.