When I make a game, I need to put it into one of two version systems. Ver. Is used for games that would get updated in a non linear fashion where there is no exact end Rel. Is used for story games when there will be an exact end to updates If a game doesn't have either, that means it's completed and will not change besides bug fixes The reason some parts are more than 9 and not adding one to the next integer is simply because that's not how it works. The first number (X.0.0) is every major update, this marks the playability of the game for Ver., but marks a main point for Rel. The second number (0.X.0) is any update that may have a name and add a bunch of new content or maybe a mechanic or rework for Ver., but can be a chapter or a side story update to the main story for Rel. The third number (0.0.X) is used for things like bug fixes, small content updates or GUI changes for Ver., but is used for smaller parts of chapters in Rel.