How to Play "Mario Kart 8" With a Friend over the Internetby Seth Amery ; Updated September 22, 2017
With 3.49 million sales in just six months, the Wii U's "Mario Kart 8" obliterated Nintendo's previous sales and review records. Much of its popularity is undoubtedly due to the game's online system, where you can race against friends as one of 16 iconic starting characters. Be sure you have a stable online connection before attempting to race online; the only thing worse than a Spiny Shell in first place is getting disconnected from the race completely.
Boot "Mario Kart 8" to the main menu. If you want to bring a local friend online for the journey, connect a second controller before continuing.
Pick "Online - One Player" if you want to race against others on your own. If you're bringing a friend, you can select "Online - Two Players." Regardless of the option you select, you'll reach the same menu on the following screen.
Select "Friends" to display a list of your friends. Any friends who are actively playing "Mario Kart 8" online have an icon appear beside their names; the icon is a black and white racing checkerboard.
Select an online friend to immediately jump into their race. You can even join in if they're in the middle of a tournament. If your friend is in the middle of a race, you'll enter Spectator Mode until it ends; you'll be able to pick a driver and join the very next race.
If possible, setting up a wired connection will provide you the most stable online experience. In order to do this, however, you'll need to install the Wii LAN Adapter (see Resources).
Besides playing with friends, you can race against other players in the community. As the names suggest, "Worldwide" and "Regional" let you play against a global community or those closer to your location. Tournaments are a series of races that anybody can join.
You can only add friends to your Wii U friends list before starting "Mario Kart 8"; you can't add friends while you're in-game.
If something is wrong with your connection, you'll get an error code trying to access multiplayer. You can look up the definition of this error code to review the specifics of the problem (see Resources).
Although friends can join your matches via the in-game friends list, you can't directly invite a friend to join your match.