Frame

A frame is the primary unit of time in the Super Smash Bros. series. Every frame, the game reads controller input, performs calculations, and renders an image on the screen. In all the series' games so far, one frame is 1/60th of a second, meaning the game runs at 60 frames per second.

The vast majority of timing-based elements on the Smash Bros. series are measured in frames (only a few are measured in seconds, minutes, or hours). For example, Mario's forward tilt in Brawl hits on frame 5, meaning it takes about 0.08333 seconds to deal damage upon inputting the attack. Players use many terms to refer to particular frames of an attack, such as invincibility frames. When invincibility frames are active, the character cannot be damaged when hit on a certain area. For example Donkey Kong has invincibility frames on his arms when using forward tilt, and cannot be damaged when hit there.

Situations can occur where the game is not capable of finishing all its calculations within one frame, resulting in a delay while it finishes up. A notable example is on Fountain of Dreams; many characters using special-effect-heavy attacks at once combined with the reflective floor can cause the game to lag as it fails to work fast enough to keep the framerate at 60FPS. This is one of the reasons the stage is banned in doubles, as even minor lag can throw off experienced players.

Many mechanics are restricted to integer numbers of frames. For example, most hitboxes take their current position and their position one frame ago into account in order to stretch between the intervening space, so a fast-moving attack cannot pass through a target without damaging it. As another example, time-slowing effects in SSB64 and Melee reduce the rendering framerate as well as the physics framerate, so using training mode to reduce game speed to 1/4x results in a noticeable drop in framerate. However, other elements utilize the concept of subframes, which allows decimal numbers of frames. For example, weight-based throws can animate at varying speeds, resulting in each drawn frame showing a subframe of each animation (such as frame 10.56). Brawl also introduces subframes for rendering slowed-down gameplay, resulting in smooth movement even at 1/4x speed, though it is unclear whether physics continue to work on integer frames only.

In Super Smash Bros. for Nintendo 3DS, assist characters' graphics are rendered at 30 frames per second. However, their physics are still applied at 60 frames per second.