Boltcaster

The Boltcaster is a weapon in Deus Ex: Invisible War. Like the mini-crossbow, it fires a poison-tipped dart, which will slowly damage the enemy until he falls down unconscious. The only groups that seems to use boltcasters are Order Seekers and the occasional thug. It's alt-fire is a scope, which makes it extremely useful for long range.

Background
"Rather than a traditional tension based crossbow, the boltcaster accelerates a bolt electromagnetically. The bolt injects a toxin that inflicts non-lethal poison damage over time."

- Deus Ex: Invisible War description

Tactics
The Boltcaster will be your primary ranged weapon in a pacifist run, as it does not kill enemies. However, make sure to fit a silencer on the gun; the boltcaster's firing sound can be heard by enemies if it doesn't have one.

In a non-pacifist run, the boltcaster can be useful to help soften up a strong enemy, (such as an Illuminati Commando). After firing a few shots at the enemy, switch to your primary weapon and finish the target off.

Unique variant
"A Black Market accelerator that launches an incendiary bolt."

- Deus Ex: Invisible War description The Hellfire Boltcaster is located in Dr. Nassif's greenhouse. Unlike the regular boltcaster, the Hellfire sets enemies on fire. Obviously, this only makes it useful for a non-pacifist run, but this makes it much better for softening up strong enemies.

Kusza energetyczna (DXIW)