Intangibility

Intangibility is a state in which a hurtbox will not be hit by attacks at all. Intangibility should not be confused with invincibility, as both are different mechanics with different effects.

Overview
There are many ways to achieve intangibility. Many universal actions such as spot dodge, roll, edge grab, the shield breaking process, among others have intangibility. Certain attacks also possess intangibility, either full body or only specific hitboxes. While a character is intangible, attacks will simply not affect them, as if they were not there at all. Since the character is not hit, a long-lasting attack (or very short intangibility time) may still hit the character once it ends. This state can be incredibly useful, as it can be used to dodge attacks and make a retreat or capitalize on a reckless opponent and punish them. Some attacks intentionally make certain body parts intangible in order to make the attack guaranteed to connect without trading with the opponent.

Intangibility does have a somewhat niche downside in that on the Planet Zebes, Brinstar, and Norfair stages, intangible characters will fall straight through the stage's lower hazard rather than sustaining damage and bouncing back up, causing an otherwise preventable KO. They may occasionally also be KO'd if they are standing on the track on Mute City (SSBM), Port Town Aero Dive or Mute City SNES. In Smash 4, Master Giant's "glowing hands" attack also completely ignores any form of intangibility as well as invincibility (including respawn).

In Super Smash Bros. Melee's, intangibility is displayed by affected hurtboxes changing from their usual yellow color to a blue color during the intangibility period. A similar feature is present in Super Smash Bros. Ultimate's Training Mode via an invincibility toggle, which causes intangible parts of characters to acquire a blue tint.

While the differences are seemingly minor, intangibility is different from invincibility. Invincibility does cause hitlag, but causes no damage or knockback.

List of intangible attacks

 * Smash attacks in this table are not charged.
 * All attacks from Smash 4 and Ultimate display intangibility values as of their latest updates.

Trivia

 * In Ultimate, if one turns on the "Intangibility display" in Training Mode, intangibility will be displayed on while he is in his helpless state, and it will appear as though he is fully intangible. This is because during his helpless animation, only his shell and torso are tangible, in order to prevent unexpected interactions.
 * If the Shadow Assist Trophy freezes a character while intangible, the character will remain intangible until being unfrozen. This offers some niche competitive strategies where an affected character can achieve intangibility before being frozen and get several seconds where they are unable to receive damage.