Super Smash Bros. for Nintendo 3DS/Controls

Although Super Smash Bros. for Nintendo 3DS is obviously playable only with the built-in buttons on the handheld, Super Smash Bros. for Wii U features a whopping 7 different control options, the highest in the series and on any Wii U game in general. In both versions, the controls can be changed in the Options Menu, so the list below only states the default options.

Nintendo 3DS / New Nintendo 3DS
The 3DS is obviously the only controller option available for Super Smash Bros. for Nintendo 3DS, but it can also be used as a controller for the Wii U version by connecting a Smash 3DS game to a Smash Wii U game. The Nintendo 3DS has most of the features found in many other controllers, but notably lacks a second directional stick. The game is not compatible with a Circle Pad Pro due to technical limitations of the 3DS, although the New Nintendo 3DS does come with a right analog rub that emulates this feature.

Due to the many similarities between the Nintendo 3DS and the standard Wii U controllers, it can be a good choice for owners of both games, as you can switch flawlessly between both versions due to familiarity with the system. However, be careful with the Circle Pad if you often engage in intense play. The Circle Pad is not as precise and not nearly as sturdy as an analog stick, and there has been many reported incidents about 3DS owners getting broken Circle Pads as a result of playing Smash.

Wii U Gamepad / Wii U Pro Controller
The Gamepad and the Pro Controller are considered the standard controllers for the Wii U version. As the controllers with the most buttons, you don't have to worry about missing out on any features. The Gamepad has additional uses in Stage Builder, using voice chat when playing online Smash and activating Amiibo.

Wii Remote
The simplest controller is also the most limited one. Without an analog stick, you have noticeably worse control over your movement and attacks, as it is harder to dash or use Strong Attacks. The lack of dedicated jump buttons also forces you to use Tap Jump by default. It is usable if you only play the game as a light and casual distraction, but once you get more invested in the game, you will certainly appreciate the expanded features of other controllers.

Wii Remote + Nunchuck
The Wii Remote and Nunchuck combination, often referred to as the "Wiichuck" for short, is better than the Wii Remote by itself, but is still fairly limited. Nevertheless, it can potentially match the functionality of dual analog controllers with a bit of control scheme modification. A common modification is to use the D-Pad for Smash Attacks, emulating the second analog stick of most controllers, while replacing one of your taunt buttons for the grab button.

Wii Classic Controller
The Wii Classic Controller is quite similar to the Wii U Pro Controller, only with the analog sticks at the bottom. As such, it offers no loss of functionality and is a more than an adequate controller for the game.

Gamecube Controller
The Gamecube controller is a favorite of many series veterans, and its use has been extended to this new iteration of Smash with the release of the Wii U-Gamecube Adaptor. The ability to use the same controller for Melee, Brawl and Smash for Wii U is a big plus, especially if you are a long-time fan that often switches between these games. The Gamecube controller is also the preferred control option in larger-scale tournaments, as it is wired to the system instead of using sensors, minimizing communication disruptions when there are many systems running at once.