CDs are collectable items in Super Smash Bros. Brawl and Super Smash Bros. for Wii U, in the same vein as trophies and stickers. Collecting a CD will unlock a new track for My Music. Both Brawl and for Wii U also have a CD trophy. The CDs in Smash look just like real world CDs.
Like trophies, certain Challenges may need to be beaten to unlock specific tracks. There are 133 CDs in Brawl, including 31 which are available only via Challenges.
Like stickers, CDs will appear in all game modes, and the chance of appearing can not be altered via the item switch. However, the frequency with which CDs appear is far lower than that of stickers and, unlike other items, CDs will only appear for a few seconds before disappearing, disappearing even faster than the Barrel Cannon in Melee. When it is grabbed, an orchestra-like sound will be heard and the screen will flash in a light green color. It can get extremely difficult to collect CDs on larger stages due to their speed of disappearance. According to the CD trophy, once all tracks have been acquired, CDs will stop appearing; CDs may still appear during a Wi-Fi battle if at least one player doesn't have all the CDs. The game won't stop players who have all CDs from collecting it.
When a CD is collected, the player(s) will be alerted to what track it contains and be able to listen to it after the match, unless it is collected during Wi-Fi play, then the alert will come some time after the player logs off. If a CD is collected when playing in Classic or All-Star Mode, and the console is turned off during a match, the player(s) will be alerted the next time the game is started. Collecting CDs in The Subspace Emissary will alert the player once the mode is quit.
CPU players will never attempt to grab a CD. However, if they do so accidentally by trying to attack or air-dodge while nearby, the corresponding track will not be unlocked.
CDs are no longer collectible items. However, they can still be prizes given in Challenges, and acquiring a downloadable stage results in unlocking the CDs of said stage's music.
CDs return in Super Smash Bros. for Wii U. They function the same as in Brawl, but are no longer dropped by Sandbag, precluding the use of CD Factories.
Figure Players picking up CDs count towards the player's total, unlike regular CPU players, but this rarely happens due to the CDs disappearing very quickly if not picked up.
CDs no longer appear online, possibly due to CDs getting stolen by players who already have all the songs in the game.
In for Wii U
The compact disc is a media storage format. Developed by Philips and Sony and officially released in 1982, the CD would grow to become one of the most popular formats over the next several decades. The CD had the advantage of being one of the earliest digital media formats and being able to hold an extremely large amount of both video and audio data relative to its size, making them very cheap to produce. A disadvantage is that the CD is among the most fragile formats, as any wear and tear could make it unusable.