Special Cup

The Special Cup is the final cup in Super Mario Kart, Mario Kart 64, and Mario Kart: Double Dash!!, as well as the last of the Nitro Cups since Mario Kart DS. In Mario Kart: Super Circuit is it the last of the "standard" courses, with the Extra Cups being unlocked afterwards and Extra Special Cup being the final cup. The Special Cup consists of long, challenging courses with lots of gimmicks and harder difficulties. Notably, this cup always culminates with Rainbow Road as the game's climactic course. Starting in Mario Kart: Super Circuit, Bowser's Castle is the penultimate course before Rainbow Road.

Aside from Mario Kart 64 and Mario Kart 8 Deluxe where the cup is available from the start, the criteria to unlock the Special Cup varies by game, although in all games, the Star Cup must be completed successfully. In Super Mario Kart, the player may unlock it by winning all three cups in 100cc (though it will be unavailable for the 50cc class); in Mario Kart: Super Circuit it is available by winning the four previous cups, each by class; in Mario Kart: Double Dash!!, it appears after the player finished first in the Star Cup in 100cc; from Mario Kart DS onwards, it is unlocked once the player claims a trophy in the Star Cup.

The emblem of the Special Cup is a smiling crown, which first appeared in Mario Kart: Double Dash!!. In previous installments the emblem is completely different, for instance, in Super Mario Kart, this cup lacks a unique emblem and instead uses a combination of the three emblems for the Mushroom Cup, Flower Cup, and Star Cup respectively; and in Mario Kart 64 and Mario Kart: Super Circuit, it is represented by the letter "S", the initial of "special."

Mario Tennis series
The Special Cup reappears in Mario Tennis Open. In this game, it is called the Champions Cup. It is the last cup in the World Open tournament series. Players can unlock this cup when they clear the Banana Cup. When players clear this cup, their character earns a star rank, which boosts their stats and grants them access to the Star Open tournament series. The Champions Cup takes place in Mario Stadium, with the hard, clay, and grass courts being used for the starting, semifinal, and final rounds respectively. Matches for this cup have one set for the starting round, three sets for the semifinals, and five sets for the finals.

In Mario Tennis Aces, a trophy based on the Special Cup appears as a reward in online tournaments.

Completion awards in the Mario Kart series
Winning the Special Cup in the Mario Kart series can award the player with various bonuses, depending on the game. Additional cups unlocked are excluded from this list.

Mario Kart: Double Dash!!

 * 50cc Special Cup: Bullet Blaster
 * 100cc Special Cup: Toad, Toadette, Toad Kart
 * Mirror Special Cup: Boo Pipes

Mario Kart DS

 * All nitro cups (includes Special Cup) on 50cc: Dry Bones
 * All nitro cups (includes Special Cup) on 100cc: Three karts for each playable character
 * All nitro cups (includes Special Cup) or all retro cups (excludes Special Cup) on 150cc: Seven karts for each playable character
 * All cups on 150cc: 150cc Mirror class
 * All nitro cups (includes Special Cup) or all retro cups (excludes Special Cup) on 150cc Mirror: R.O.B.
 * All cups on 150cc Mirror: All karts for each playable character

Mario Kart Wii

 * 50cc Special Cup: Piranha Prowler
 * 1 star rank or higher on all nitro cups (includes Special Cup) on 50cc: Baby Daisy
 * 100cc Special Cup: Mii Outfit A
 * 1 star rank or higher on all nitro cups (includes Special Cup) on 100cc: Sneakster
 * 150cc Special Cup: Daisy
 * 1 star rank or higher on all nitro cups (includes Special Cup) on 150cc: Dry Bowser
 * All cups on 150cc: 150cc Mirror class
 * Mirror Special Cup: Phantom
 * 1 star rank or higher on all cups on 150cc Mirror: Rosalina

Mario Kart 7

 * All cups on a single cc class: Mii
 * 150cc Special Cup: Metal Mario
 * All cups on 50cc, 100cc, and 150cc: 150cc Mirror class

Mario Kart 8
Most unlockable characters in Mario Kart 8 are unlocked at random upon winning Grand Prix cups (separate cups must be played to unlock characters), which includes the Star Cup. Characters that can be unlocked include Rosalina, Metal Mario, Lakitu, Toadette, Baby Rosalina, Pink Gold Peach, Iggy Koopa, Roy Koopa, Lemmy Koopa, Larry Koopa, Wendy O. Koopa, Ludwig von Koopa, Morton Koopa Jr., and Mii. Mii is unlocked upon the eighth Grand Prix cup victory, unless an amiibo is used to unlock Mii beforehand.

In addition, the Gold Standard body can be unlocked by getting a 1 star rank or higher on all non-DLC cups (including the Special Cup) on any one engine class, and the 150cc Mirror class can be unlocked by winning all 150cc cups.

Mario Kart 8 Deluxe

 * 1 star rank or higher on all cups on 150cc Mirror: Gold Standard
 * All cups on 200cc: Gold Mario

Trading Card info
"Two Special Cup tracks, Bowser's Castle and Rainbow Road, have been Special Cup stalwarts. This time around the names may be the same, but the layouts are new & improved—and they're no cakewalk. In fact, these could be some of the most difficult tracks in Mario Kart Wii."

Trivia

 * In the Time Trial and VS modes of Super Mario Kart, the player can access the Special Cup before unlocking it by pressing buttons in this sequence:.
 * In the Chinese version of Mario Kart 64, the Special Cup is called the "iQue Cup", named after the China-exclusive iQue Player home console.
 * If Grand Prix mode in Mario Kart Wii is highlighted, the Special Cup trophy from that game can be seen in the background.
 * None of the Special Cup courses from Mario Kart Wii and Mario Kart: Super Circuit have appeared as a retro track in a future Mario Kart installment.