Mario Kart 8 Deluxe – Booster Course Pass

The Mario Kart 8 Deluxe – Booster Course Pass is a DLC expansion pack for Mario Kart 8 Deluxe, announced during a Nintendo Direct held on February 9, 2022. The pack includes 12 additional cups, for a total of 48 additional courses (bringing the total number of courses in the game to 96), most of which are remastered versions of courses from other Mario Kart games, including Mario Kart Tour. The courses also received visual improvements and new music arrangements, and are based on their designs from Mario Kart Tour (with the exception of Yoshi's Island, which is currently absent from said game). The pack marks the longest gap between the original release of a Mario game and the release of its DLC, releasing nearly five years after Mario Kart 8 Deluxe did. The pack also makes Mario Kart 8 Deluxe the first Mario Kart game to feature classic courses from games following the original game's release, with Mario Kart Tour and its reappearing courses debuting after 8 Deluxe was initially released. In addition to the courses, starting with Wave 4's release, the pass also features brand new playable characters for the game.

The pack is set to be released in six waves by the end of 2023. It can be purchased on its own, but is also included in the Nintendo Switch Online + Expansion Pack membership as well as in the digital-only Mario Kart 8 Deluxe Bundle (Game + Booster Course Pass). The first wave of the DLC was made available to pre-load on March 15, 2022, and was released on March 18, 2022. In Mainland China for the Tencent release, waves release later than they do internationally, with the pack set to completely release by the end of 2024 rather than 2023. If the player has purchased the Booster Course Pass or currently has a Nintendo Switch Online + Expansion Pack membership, a small icon of a Super Star can be seen next to the version number on the game's title screen.

The courses shown in the key artwork use official screenshots and in-game course icons from Mario Kart Tour. Some screenshots of the courses show Paris Promenade and Paris Promenade 3 with barrier fences from that game, as well as an official screenshot of the ninja Shy Guys in Ninja Hideaway, which originated from the Ninja Tour's in-game preview. Prior to Wave 1's release, the infographic showing all of the known courses across all six waves also used Tour screenshots. However, in the launch trailer for Wave 1 posted following its release, the infographic was updated to use in-game screenshots from 8 Deluxe for all courses, which the release trailers for future waves would follow as well.

Several minor adjustments to the courses in Wave 1 were made upon the release of Wave 2, such as their course icons being slightly brighter, and the sand and dirt on some courses now leaving tire marks. Additionally, the final car section in was adjusted, making the cars serve as hazards and move sporadically in random directions (except for in Time Trials, in which they remain stationary).

Courses
Each of the six waves features two cups, each with four courses, for eight courses per wave. As of the third wave, there is one course from Super Mario Kart, two courses from Mario Kart 64, three courses each from Mario Kart: Super Circuit, Mario Kart DS, Mario Kart Wii, and Mario Kart 7, eight courses from Mario Kart Tour, and two new courses. Excluding the Tour courses, and  are currently the only classic courses in the Booster Course Pass that had not previously appeared as classic courses in other games, while Sky-High Sundae and Yoshi's Island are currently the only courses to make their series debut in the pass.

Ninja Hideaway and Merry Mountain lack the "Tour" prefix, despite both debuting in Mario Kart Tour. Furthermore, despite making its debut in the Booster Course Pass, Sky-High Sundae is labeled and marketed as a new course in both the pass and Mario Kart Tour. In the Tencent release of the DLC in Mainland China, all courses from Mario Kart Tour lack the "Tour" prefix, likely due to Mario Kart Tour's unavailability from app distribution platforms in Mainland China.

In the British English version of the pass, is known as, as was the case in the British English version of Mario Kart 7. However, courses that had different names between European French and Canadian French in previous games instead use their European French names in the pass in both versions.

Yoshi's Island is among the courses included in the fourth wave; however, its position is yet to be revealed.

Characters
Included alongside the eight courses in Wave 4 is one character, Birdo, making her playable debut in Mario Kart 8 Deluxe. Similar to the Yoshis and Shy Guys in Mario Kart 8's downloadable content, Birdo has various colors: pink, orange, yellow, blue, light blue, green, red, black, and white. Additional returning characters will also be included after Wave 4.

Internal content
An alternate version of the key artwork exists in the game's files as of version 2.0.0, showing several currently unreleased courses. As with the official artwork, this banner uses official screenshots and in-game course icons from Mario Kart Tour, including icons for trick and reverse/trick variants. Several tracks included in Wave 2 were found in this banner before their official announcement, including and Sky-High Sundae, though the  art used within it is not that of. Several more courses are too blurry to be properly identified; however, the starting area of, the snowboarding section of , the underwater portion of , and several Tour city courses can all be made out, notably including Amsterdam Drift and Bangkok Rush before their official reveals for Tour.

In the game's internal data in version 2.0.0, many upcoming course slots were each designated a prefix. Across waves 2-6, "SNES" (denoting a Super Mario Kart course) was allocated to two upcoming courses, "N64" (Mario Kart 64) to one upcoming course, "GBA" (Mario Kart: Super Circuit) to four courses, "GCN" (Mario Kart: Double Dash!!) to four, "DS" (Mario Kart DS) to three, "Wii" (Mario Kart Wii) to five, "3DS" (Mario Kart 7) to two, and "Tour" (Mario Kart Tour) to twelve, in addition to seven courses without a prefix. The prefixes, which matched the courses in Wave 2, were removed in version 2.1.0 with that wave's release; however, Wave 3's lineup was slightly different, with several courses changing positions, and a GCN course not appearing in favor of.

In version 2.1.0, music snippets for many unreleased courses were added to the game's files, including, /Wario Colosseum, all of Mario Kart Tour's new courses up to , and every course that would go on to be featured in Wave 3. These music snippets were removed with Wave 3's release in version 2.2.0.

Trivia

 * The official North American webpage for the pass has had numerous errors over time:
 * The pass was once briefly referred to as the "Mario Kart 8 Deluxe – Booster Course Pack" on the site.
 * was once briefly labeled as a 3DS course instead of DS.
 * Following the reveal of Wave 3 and until its release, the website erroneously stated that Wave 3 would be available on December 7, 2023 rather than 2022.
 * The countries of most of the 150cc staff ghosts for Mario Kart Tour's city courses match the cities' respective countries:, , , , and ' staff ghosts are French, Japanese, American, British, and German respectively.
 * 's is the current sole exception, with a Japanese staff ghost rather than an Australian one; no staff ghost in Mario Kart 8 Deluxe is Australian.