Sawed-off shotgun

In Deus Ex, the sawed-off shotgun is a pump-action shotgun used by thugs and militias. Its small size makes it easy to conceal. Because of its short barrel, its pellets have a wide spread if the Rifle skill isn't at Advanced or Master, making it difficult to use past short range.

The shotgun can be found in a sunken boat near the docks where you meet Harley Filben during the first mission. If not picked up there, various NSF troops use it. If not picked up from them, it can be found lying on the ground in various areas.

It appears to be based on the SPAS-12.

Tactics
Of the two shotguns, the sawed-off one is better against organic enemies. The extra five damage each pellet does can mean the difference between a kill and a target surviving, especially if you aim for the head. The pumping between shots leaves you extremely vulnerable between shots, so make sure that you aim for the upper part of your target's body before firing.

With Sabot shells, the sawed-off shotgun is difficult to use against robots, as they will constantly fire on you while you're pumping. However, it can destroy cameras with one or two shots, depending on your Rifle skill level.

An unmodded sawed-off shotgun can be difficult to use. It's recoil is enormous, making it hard to fire follow-up shots with any degree of accuracy. Its magazine is small, meaning that you'll have to make every shot count in combat, and its long reloading time will make you even more vulnerable than pumping the shotgun does.

A modded sawed-off shotgun is a useful weapon to have, especially if your Rifle skill is high. Recoil reducers make it possible to hit targets with quick follow-up shots. Clip mods can make the magazine hold up to nine rounds, meaning that you don't have to worry about having to reload during combat. A modded sawed-off shotgun combined with a high Rifle skill will turn you into a monster in close quarters combat, so invest in it if you're focusing on the Rifle skill for whatever reason.