A wavedash is a technique/physics engine exploit in Super Smash Bros. Melee and Super Smash Bros. Ultimate that is performed by air dodging diagonally into the ground, causing the character to slide a short distance. While it is uncommon in casual play, high-level play of Melee effectively requires proper use of the technique; the Melee community sees wavedashing as an advanced technique superior to dashing because it allows players to perform any ground action while moving horizontally on the ground. Use of the technique is especially important for the metagame of characters with poor traction, such as Luigi, Mewtwo, and the Ice Climbers, and almost every other character requires some use of wavedashing for positioning and maneuvering, particularly in combos and mindgames.

When air dodging diagonally to the ground, all of the momentum of the airdodge is transferred into horizontal (ground) movement, since the character can no longer fall. Additionally, performing a wavedash causes the game to recognize the character as landing from the helpless state due to air dodges causing the state. Thus, the game is not recognizing wavedashing as a specific "technique" like attacking or walking, but instead, as if the character simply landed and stood still; the sliding effect is due to the "slipperiness" inherent in the game's engine.