You should show appropriate cause in a formal manner. You can modify this format as your requirement.
Useful for people who made a game and uploaded it and then their hard drive with the source files exploded. Using this tool on other people's games might be considered 'reverse-engineering'. If you have doubts about the legality of doing so, consider reading the terms EULA of the game you are trying to reverse-engineer and consider reading this stackexchange thread.