User summary: The Paradox Basic Rulebook, Version 4, is published only as online HTML; in several places it is referred to as a "beta" release. Several sections have been added to the Version 3 presentation but many of these new sections remain as stub entries only. The primary addition involves the "Realms", or meta-setting, for the game, though only the Spiritual Realm is fully defined. Additional material clarifying some aspects of action resolution are also provided.