Kinetic energy transfer is relatively minimal in airsoft compared to that of paintball.
A airsoft projectile weighing .2 grams and traveling at 300 feet per second (90 meters per second) transfers about 1 joule of energy.
A paintball projectile weighing 2.84 grams and traveling at 300 feet per second transfers 11.8 joules. Although there is a considerable difference between airsoft and paintball energy levels (1 joule verses 12 joules), the type of collisions that occur (elastic airsoft vs. inelastic paintball) must also be considered (refer to Pellet Ballistics).
Most airsoft guns are capable of shooting from 250fps to 400fps. A hop-up unit, if present, puts backspin on the pellet giving a slight upward arc. This gives an airsoft gun more range than an airsoft gun without a hop-up unit.
Airsoft playing fields usually have rules specifying what velocity is allowed for each player position. This makes the game much more realistic, as an airsoft pellet will not travel as far as a real bullet.