Knockback resistance, also referred to as launch resistance, super armor, or heavy armor, is a physics trait in Super Smash Flash 2 carried over from the Super Smash Bros. games that limits knockback, hitlag, and hitstun in certain cases. It only affects knockback and the character who is hit will still receive damage from the attack. Yoshi's midair jump is an example of a move that has finite amounts of knockback resistance, and commonly referred to as having heavy armor. Some other knockback resistance moves have infinite knockback resistance and are commonly referred to as super armor. However, grab hitboxes ignore all variations of launch resistance. There is no knockback resistance mechanic in Super Smash Flash.
Knockback resistance is not to be confused with invincibility frames, which leave an opponent immune to damage as well as knockback or flinching.
Characters with moves that grants them knockback resistance
- Black Mage's dash attack grants him super armor from the point where he turns into stone until the end of the attack. This means he has resistance even after he comes out of stone form until the move ends.
- Donkey Kong's Giant Punch grants him super armor if fully charged, Spinning Kong grants him super armor in the initial frames, and dash attack grants super armor too.
- Yoshi's midair jump grants him a variation of super armor, which ignores any sort of knockback below a threshold.
- Certain Final Smashes, Final Forms and Semi-Final Forms grants the user infinite knockback resistance.