An up tilt (abbreviated "u-tilt"), officially called a strong up (上強攻撃, Up/above/upper strong attack) before Ultimate, is a tilt attack that can be performed by any character by holding the control stick lightly upward and pressing the attack button while on the ground. It can be difficult to pull off an up tilt quickly, as if the player tilts too fast, they'll either jump or do an up smash instead. Turning off tap jump can help avoid the former problem, or the player can do some other action and hold up on the control stick before it ends.
Since the Wii Remote-only control scheme lacks both a control stick and any other way to jump, up tilts become unusable without first holding up during a prior action, making them the only normal attack which a player may not be able to use for no in-game reason.
List of up tilts
Notable up tilts