Launch rate

Damage ratio is a feature in all three Smash Bros. games that alters how much knockback is given and received. All knockback in a match is multiplied by the damage ratio value, which by default is 1.0 but can be set from as low as 0.5 (attacks have half knockback) to as high as 2.0 (attacks have double knockback). The minimal damage ratio is ideal for combos while the maximum damage ratio is ideal for OHKOs.

Despite the name, the value affects knockback, not damage.

Damage ratio is not to be confused with handicap, which is another feature that increases/decreases knockback, but in an entirely different way.