ROM hacks, also called hack games or even ROM stains , are video games which were edited or changed by enthusiasts.
The core string Pokémon game process is thought to be very versatile and lends itself well to modification, giving anglers a lot of creative freedom along with a solid, well-tested game engine. These factors, as well as Pokémon's notable popularity throughout the globe, has lead to the development of tens of thousands of distinct games spanning a number of generations, which range from minor alterations to additional new attributes andmuch more and more frequently, brand-new fan-made Pokémon games. Although the core-series is undoubtedly the most popular collection to hack, there are also many fan-created Pokémon games that do not use these as foundation, and instead are, by way of instance, modified versions of the Pokémon Mystery Dungeon series and Pokémon Conquest.
These are unauthorised copies of published games that are sold to consumers, often flashed on after-market game paks or game cards and inducing the official Nintendo Seal. But because ROM hacks are usually dispersed across the Internet for free, they are often sold as bootleg games, typically against the consumer's wishes. The reliability of these bootlegs are often poor, and is becoming such an issue that hackers have started to introduce warning displays in their games, cautioning users who if they paid for this, they may have been scammed.

Early Pokémon ROM hacks date back into the late 1990s with modified variants of Pokémon Red. These were frequently relatively minor adjustments like sprite or dialog changes, and will generally follow the flow of the game. These early ROM hacks were infamous for being especially primitive in nature, which range from swapping Pokémon and human sprites about to replacing the dialogue with obscene Helpful resources text.


This trend continued until the release of Pokémon Brown by consumer Koolboyman at the early 2000s, among the most notable Pokémon hacks ever. This is the first hack to completely re-invent the match, using a brand new region and totally new plot. Later editions included an enlarged Pokédex (including Pokémon from Generations II, III and IV), additional dungeons and additional plot tweaks. It's one of the few finished hack games and was successful enough to justify a sequel (Pokémon Prism, a Pokémon Crystal-based hack) and a Generation III variant (Pokémon rijonAdventures) based on Pokémon FireRed.
Since Brown,'' Pokémon hacking notoriety has expanded exponentially, together with developers creating many applications tools for desktop operating systems to help produce maps, edit sprites, images as well as creating scripting languages especially for the Pokémon match engine. It has also motivated many hackers to learn how to edit the games' gathering code directly (known as ASM hacking). Various hacks have been published, often using FireRed as a foundation, for example Pokémon ShinyGold, Pokémon Naranja along with also the Pokémon Ruby Destiny show, merely to mention a couple.
There are numerous websites devoted to Pokémon ROM hack development. A number of these websites hold award nominations and services to showcase a few of their greatest talents of their neighborhood.