Though the "Universe" (宇宙, Uchū?) permits the birth of unlimited possibilities, countless Adjacent Worlds, and divergent developments of history, as the unrestricted propagation of this process would quickly exhaust the Universe's lifespan, those extraneous WorldsRoutes (世界ルート, sekairūto?) removed of the category of "timelines characterized by strength and stability" are periodically culled (伐採, basai?) by the existence known as the World (世界という者, Sekai to Iu Mono?, lit. "the thing called the World")[2] so as to prevent the needless expenditure of energy.[1] The facilitation of this process is referred to as the Conservation of Phenomena (事象保存, Jijō Hozon?), effected by way of a heuristic audits (集計, Shukei?) of cumulative timeline survivability (進むと可能性, susumu to kanōsei?, lit. "prospects and potential")—judging the persistence of a timeline's Parallel WorldsBranching Potential (平行世界かのうせい, heikō sekaikanōsei?) across the subsequent century.