A W3G file is a replay file generated by the popular real-time strategy video game Warcraft III, developed and published by Blizzard Entertainment. When players participate in a match, whether online through Battle.net or in single-player custom games, the game engine records all player actions, mouse clicks, keyboard shortcuts, unit movements, and game events into this compact data file rather than capturing a heavy video stream. Because it only stores the chronological sequence of inputs, the resulting file size is extremely small, typically just a few megabytes or kilobytes. To watch the replay, the Warcraft III game client itself must be used to interpret the command stream and visually recreate the match in real-time. This allows users to review their gameplay from multiple perspectives, analyze strategies used by top-tier players, study opponent build orders, and learn advanced micro and macro management techniques. Furthermore, W3G files are essential for the competitive esports community, as they serve as definitive proofs of match outcomes, enable caster analysis, and are frequently shared among community platforms and tournament organizers.