A shotgun, also called a "scattergun", is a firearm designed to shoot a multitude of lead or steel balls of varying sizes. This makes it very effective at hunting game, greatly increasing the weapon's hit potential. However, the accuracy and power found at close range diminish rapidly as you get farther away from the target. Shotguns designed for military use are often called "combat shotguns".
The sawed-off shotgun is a one-handed weapon and reaps the benefits of the Gunslingerperk.
This weapon has one of the largest spread of all weapons in Fallout 3, second only to the experimental MIRV. In order to get high damage, you essentially have to treat the gun like a melee weapon and fire it at point blank range so that all the shot impacts the target.
In Fallout: New Vegas, the sawed-off shotgun fires both barrels simultaneously; in Fallout 3 the gun fires the each barrel in sequence.
A fully-repaired sawed-off shotgun can fire 167 shots, or 84 reloads, before breaking.
The Kneecapper - Handled by Ronald Laren, The Kneecapper is far more powerful than a sawed-off shotgun or even a combat shotgun. It's also lighter and more accurate than the regular sawed-off, but fires slightly slower and is less durable.
Mel wields a sawed-off shotgun in a random encounter in which he attempts to mug the Lone Wanderer, but the gun is not loaded. This is an homage to Mel Gibson, the actor who played Mad Max. In Mad Max 2, Gibson threatened the Gyro Captain using an unloaded sawed-off shotgun.
pcps3xbox360 The shells are never "ejected" from the sawed-off. The barrel is pointed down while reloading, giving the illusion that the spent shells have fallen on the ground, but the third-person view shows that the shells are simply cleared from the barrel, without being ejected.