PCN (Portable Chess Notation) provides a comprehensive, JSON-based format for representing complete chess game records across variants. This gem implements the PCN Specification v1.0.0 with a modern Ruby interface featuring immutable game objects and functional programming principles. PCN integrates the Sashité ecosystem specifications (PMN for moves, FEEN for positions, and SNN for style identification) to create a unified, rule-agnostic game recording system. Supports traditional single-variant games and cross-variant scenarios where players use different game systems, with complete metadata tracking including player information, tournament context, and game status. Perfect for game engines, database storage, game analysis tools, and archival systems requiring comprehensive game record management across diverse abstract strategy board games.