A matchup, sometimes shortened to MU, refers to the estimated performance of a particular character versus another in competitive matches if the two players are of equal skill. This estimate can be expressed in many various ways, such as numerically in the form of a ratio. Since there is much contention in the community as to whether this type of measurement is misleading, another common way is to use a discrete scale (such as from -4 to +4) to denote the difficulty of a matchup. All character matchups are often organised into charts, and each Smash game has its own based on official tier lists. Super Smash Bros. 4 and Super Smash Bros. Ultimate have no widely agreeable character matchup chart at this time.
This is a list of the character matchup charts in the first three Super Smash Bros games (with Smash 64 having two separate lists for the Japanese and North American versions). Keep in mind that these lists were made many years ago and are considered outdated: