ROM hacking is the process of altering the data of a video game to varying levels.
The extent of a hack can range from minor alterations of graphics, sound, or gameplay mechanics, to creating almost entirely new games based on a pre-existing engine.
The term "ROM hack" is mainly attributed to fan-made works and usually does not encompass official works that meet similar guidelines.

Popular Hacks

• A Slice of Life
• Pokemon Plus Green
• Pokemon Ruby 2
• Hito: A Broken Story
• The Power We Hold
• The First Completely Open World Pokemon – Clay’s Calamity II
• Pokemon Mystery Dungeon – Red Rescue Team Kaizo
• Pokemon meets Final Fantasy
• Pokemon Creepy Black
• Pokemon Emerald Nuzlocke