Portable Move Notation (PMN) v1.0.0 is a rule-agnostic, JSON-based format using arrays to represent deterministic state-changing actions in abstract strategy board games. This gem provides a consistent Ruby interface for serializing, deserializing, and validating moves across Chess, Shogi, Xiangqi, and other traditional or non-traditional variants. The v1.0.0 format uses simple 4-element arrays: [source_square, destination_square, piece_name, captured_piece], making it compact and language-agnostic while focusing on deterministic state transformations independent of game-specific rules.