Aim assist on Halo 1

There are four types of aim assist in Halo titles: Snapping, Friction, Acceleration, and Magnetism.

Magnetism defines and outlines how far a bullet will “bend” in order to hit an enemy. Bullets and projectiles do not necessarily travel in a straight path; they will curve very slightly in order to hit a target. Different projectiles will experience different curvatures.
Snapping reorients the player’s camera toward enemies whenever a player’s reticle are in proximity to their target.
Acceleration makes it so that when the player pegs their aiming stick in one direction the player’s reticle will start moving slowly in that direction then pick up speed.
Friction slows the player’s turn rate as soon as their reticule passes over an enemy. What it does is that it slows the player’s top speed, and then dramatically decrease the rate at which the crosshair will slow down when the player release the stick.

https://www.halopedia.org/Aim_assist

https://youtu.be/Q4aBhJy6zog