ROM hacking

ROM hacking is the process of modifying a ROM image or ROM file to change or alter the contents contained within, usually of a video game to alter the game's graphics, dialogue, levels, gameplay, or other elements.

ROM hacking is used to improve an old game of importance, as a creative outlet, or to essentially make new (unofficial) games using the old game's engine. ROM hacks are generally accomplished through the use of a (a program for editing non-textual data) and various specialized tools such as tile editors, and game-specific tools which are generally used for editing levels, items, and the like, although more advanced tools such as assemblers, compilers and debuggers are occasionally used. Once ready, they are usually distributed on the Internet for others to play on an emulator or a games console.

Fan translation (known as "translation hacking" within the ROM hacking community) is a type of ROM hacking; anti-censorship hacks exist that restores a game to its original state (which is often seen with older games that were imported, as publishers' content policies for video games (most notably, Nintendo's) were much stricter in the United States than in Japan or Europe); randomizer hacks were created to shuffle entity placements within a game; some hacks also reimplement features that exist in the game's code but are not used in-game.