Two guns in the same shooter can demand completely different aiming even at identical damage. The difference is usually whether the shot is resolved instantly or simulated as an object moving through the world.
A hitscan shot resolves in the same instant
Hitscan means the game draws an invisible line from the muzzle to wherever the crosshair points, checks what that line touches first, and applies damage immediately.
Nothing travels. The shot is a geometry question answered in one frame, so distance costs the player nothing beyond whatever damage falloff the designer applied.
This makes the weapon feel direct and dependable. If the crosshair was on the target when the trigger was pulled, the hit registers.
A projectile is an object with a life of its own
A projectile weapon spawns something that moves. It has a speed, often gravity, sometimes a collision size, and it exists in the world for several frames before reaching anything.
That travel time means the player must aim where the target will be, not where it is. Range now costs accuracy, because a longer flight gives the target more time to move.
Projectiles also make cover behave differently. A shot can be intercepted mid-flight, and arcing rounds can be thrown over geometry that a straight line could never pass.
Leading is a skill that has to be taught
Aiming ahead of a moving target is a learned estimate of speed and distance, and it is far harder than tracking a crosshair.
Designers usually help by making projectiles large, fast or visible, so the player receives feedback about how far off the estimate was rather than simply missing.
The payoff is a higher skill ceiling. Two players with equal reflexes can be separated by how well they read movement, which hitscan weapons rarely reward.
The choice reshapes the map
Long open sightlines suit hitscan, because the shot ignores distance. Filling a map with them pushes the whole game towards precise aim at range.
Projectiles reward corners, verticality and short broken sightlines, where travel time is small and arcs can be used to reach a target that is not visible.
Level designers therefore build around the weapon set rather than after it, and a map that suits one style tends to feel dead when played with the other.
Most shooters deliberately mix both
Rifles and pistols are commonly hitscan so that ordinary combat stays legible, while rockets, grenades and bows are projectiles that reward prediction.
The mix gives the balance team a lever that is not damage. A weapon can be weakened by slowing its projectile rather than by reducing the numbers players read.
It also spreads the roles. A team can hold an angle with instant fire while another player uses travel-time weapons to make that angle uncomfortable to stand in.