The Nintendo Wi-Fi Connection (also known as WFC) is a service that allows users of the Nintendo DS and Wii to play against other people on their respective console online. Many games are compatible with WFC.
On January 26, 2012, it was announced by Nintendo during an investors' meeting that the Nintendo Wi-Fi Connection service will be succeeded by and absorbed into Nintendo Network. This new online system will eventually unify the 3DS and Wii U platforms and replace Friend Codes, while providing paid downloadable content, an online community style multiplayer system, and personal accounts. Nintendo Network is fully supported on the Nintendo 3DS and on the Wii U, whilst still continuing providing partial legacy support for both Wii and Nintendo DS under the Nintendo Wi-Fi Connection brand. Specifically, the Wii U can boot to Wii mode and then access the Wii Message Board messages which have been recorded by the gameplay progress of compatible local games, but it cannot send Wii Message Board messages remotely between different machines.
The Nintendo Wi-Fi Connection service was terminated on May 20, 2014 for all Wii and DS games; online play features incorporated into these games are no longer available. The shutdown is connected to the shutdown of multiplayer services by GameSpy, who was acquired by Glu Mobile in 2012. 3DS and Wii U games are not affected by the shutdown because their multiplayer platform uses Nintendo's own infrastructure instead of a third-party service. The Wii Shop Channel, DSiWare shop, third-party video services, and the Pay & Play variants will remain active for the moment.
The shutdown had an immediate effect on all Nintendo-published Wii and Nintendo DS titles, however it may not necessarily apply to certain third-party titles, which could have separate servers running their own games' online functions. For example, Electronic Arts revealed that some of the games they published on the Wii and Nintendo DS had their online support terminated on June 30, 2014.
A small selection of online-enabled Wii games, such as Dragon Quest X and FIFA 12 through 15, which by happenstance are not branded under the Nintendo Wi-Fi Connection, may continue using their online functions normally.