

While Nintendo's original lawsuit was dismissed on the basis that the devices could be used to make homebrews and develop software in 2009, the 2011 ruling reversed this, and the Paris court of appeals ruled against five R4 sellers and distributors. In October 2011, the R4 cards were banned in France. Nintendo claimed that the cards were not only seized for the benefit of their own company, but the benefit for over 1400 video game companies that depend on the sales of their games. 100,000 copying devices including R4s were seized in 2009. After the news broke, Nintendo released on a statement saying that they do support game developers that create their own applications legitimately. However, bypassing Nintendo's security system is against the law in the United Kingdom. The defence of Playables Limited claimed that the R4 flashcards were legal because it uses a homebrew application. The ruling outlawed any sales, importation, or advertising of the R4 flashcards. In 2010, the company Playables Limited, importers of R4 flashcards, was ruled against by the London High Court. In late 2007, Nintendo began a legal crackdown with a series of raids against R4 merchants. The R4 flash cartridges are banned in some countries due to copyright infringement lawsuits from Nintendo. Since the 3DS's secure boot signature validation has been broken, this provides a useful means of installing custom firmware on a 3DS. Some of these cartridges can also store a 3DS boot image a 3DS can in turn be made to boot from the cartridge by way of an undocumented button combination recognized by the system's bootloader. The R4 flashcard's original developer stopped producing the R4 Card that plays ROMs and homebrew for the Nintendo DS, however, there are a new line of R4 clones that have taken its place, notably the R4 3DS, R4 Gold, R4 DSi and R4 NES, which are used to play ROMs and homebrew from various Nintendo platforms such as the Nintendo 3DS, Nintendo DSi, Nintendo DSi XL and Nintendo Entertainment System. This allows the user to run homebrew applications, to store multiple games on a single memory card, and to play games that have been backed up by the user.

It allows ROMs and homebrew to be booted on the Nintendo DS handheld system from a microSD card. The R4 (also known as Revolution for DS) is a series of flash cartridges for the Nintendo DS handheld system. The R4i Gold 3DS, a later clone of the original R4 Card.
