Movement steps

Typically, Mario's position is updated incrementally using his velocity. These increments are called steps, and they behave differently when Mario is on the ground, in the air, in water, hanging, and climbing a pole. When on the ground or in the air, these steps typically occur four times per frame, and are commonly referred to as quarter steps or sometimes quarter frames.

Steps are also responsible for detecting collision with surfaces, updating Mario's referenced surfaces, and updating Mario's water level.