Hitlag

Hitlag, also known as hitstop and freeze frames, is a phenomenon that appears in Super Smash Flash 2 and Fraymakers. When an attack connects, both the attacker and their opponents will momentarily freeze in place. The hitlag applied to the attacker is referred to as self-hitlag or self-hitstop and is generally smaller than the hitlag applied to opponents.

Hitlag occurs with attacks that cause characters to flinch and is active during a character's flinching animation. Hitlag is also applied when hitting a shielding opponent, and hitting an invincible opponent applies only self-hitlag. Attacks that do not cause flinching, such as pummels and windboxes, subsequently do not cause hitlag.

The amount of hitlag applied depends on the attack. Weak attacks such as neutral attacks generally have minimal hitlag, whereas stronger or sweetspotted attacks can have more significant hitlag. In SSF2, electric attacks have increased hitlag, and the target can receive reduced hitlag by crouching when hit. Additionally, projectiles that apply hitlag do not apply self-hitlag, leaving the attacker's movement uninterrupted.

Smash directional influence can be performed while the target is experiencing hitlag after getting hit. It allows the player to change their position and potentially break out of combos.

Hitlag is not present in the original Super Smash Flash, as characters will instantly enter hitstun upon getting hit.

In Super Smash Flash 2
The hitlag formula used in Super Smash Flash 2 is similar to the one used in , except it is about half the number of frames, plus one. The formula used to calculate hitlag is ${c ~ \times ~ e ~ \times ~ \frac{\frac{d}{3} ~ + ~ 3}{2}\ ~ + ~ 0.5}$, where $c$ is determined by whether the opponent is crouching (2/3 if crouching, 1 if otherwise), $e$  is determined by the electric effect (1.5 if the attack is electric, 1 otherwise), and $d$  is the damage the attack dealt. For self-hitlag, the formula is ${\frac{\frac{d}{3} ~ + ~ 3}{2}}$.