Nintendo Wi-Fi Connection is Nintendo's free online gaming service for the Nintendo DS and Wii consoles. Nintendo Wi-Fi Connection (typically abbreviated "WFC" or "NWC") allows users to take advantage of titles that support the service via a wireless router or the Nintendo USB Connector. This service also allows one to link his or her Nintendo Wi-Fi Connection records to his or her My Nintendo account, and track your scores on Nintendo's official Nintendo Wi-Fi Connection website (see "External Links").
On the Nintendo DS, each game cart generates a "friend code" which can be exchanged with other owners of the same game in order to engage in online play with that person. Some titles that utilize Nintendo Wi-Fi Connection support random match-ups, but a few titles only allow online play between users who have swapped and registered their respective "friend codes."
On the Wii, "friend codes" are apparently only used for online play and information exchange when Nintendo DS-Wii Connectivity is involved. Otherwise, each Wii console utilizes its own, built-in Wii Number. Those who have exchanged Wii Numbers are allowed to play against each other in any title that does not utilize the aforementioned "friend code" system.
In little over two months after the launching of the service, Nintendo Wi-Fi Connection racked in three million connections through 500,000 unique users.
At the release of wi-fi over one million people logged on at midnite to play.
On the first two wifi games ever (Mario Kart DS & Tony Hawk American Sk8teland) the Wi-fi logo was printed on the left bottem corner on the game box rater than the top left corner which it has been printed on all the other wi-fi games since.
The "friend code" system has been the source of numerous complaints throughout the gaming community for destroying the potential for an online Nintendo community due to its restrictiveness.