Wasteland captive

Captives are imprisoned humans captured by Super Mutants. They are found at Super Mutant encampments throughout the Capital Wasteland, usually kneeling in groups with their wrists bound in front of them by rope that seemingly isn't there until you free the captives yourself.

Most people in the Wasteland say that they do not know why Super Mutants choose not to kill and eat their captives, but some events suggest two main reasons. During the quest Big Trouble in Big Town some humans from Big Town are captured by Super Mutants and held in the Police HQ in Germantown. Apparently these humans have been captured to be used as food. While in the Police HQ, a Super Mutant can be overheard conversing with a human who is about to be killed. The human asks why he is to be killed when there are plenty of human remains available (presumably from other captives). The Super Mutant jailer reveals that they prefer their food to be from a fresh kill.

A friendly Super Mutant, Uncle Leo, suggests that captives are used to create new Super Mutants. This is corroborated by dialog overheard from other Super Mutants in other parts of the Wasteland, who remark that they need more new recruits, and so they must abduct more humans to transform into Super Mutants (using green stuff), which would be consistent with the method of Super Mutant creation practiced by the Master.

Releasing captives results in a karma boost. Care should be taken that you do not accidentally kill the captive while killing their captors. A stray missile will kill them easily, or even a Frag Grenade poorly thrown by a mutant.

While escaping captives may end up being killed by any surviving mutants or other hazards in the wasteland, you can escort captives until they are out of Capital Wasteland. There's no bonus of doing so, except that you may get to discover many new places in the map if they have not been discovered already, since captives tend to walk past a lot of those places.

Captive sites can be spotted from a distance by looking for gore bags. These bags often contain ammo and caps. Captives can also be heard sobbing or calling for help if they detect you.

Be careful around captive locations, there are often mines, rigged shotguns, or grenade bouquets around. These grenades might just accidentally kill the captive for you.

If you execute the captive you will lose karma, although it seems to balance out if you release the captive and then kill them.

If you ignore a captive or choose to leave them to their fate, a new captive will eventually respawn along with new Super Mutant guards if you revisit the location. However, if you free the captive, or if the captive is killed, then no new captives will appear in that location (thus the appearance of a captive can change - althought it's a new spawn, the game simulates the captive still being there).

Captive locations

 * One is halfway between the Jefferson Memorial and Rivet City. It is difficult to walk between the two places without noticing a pocket of 3-6 super mutants. The mutant at the top holding a minigun stands next to the captive. There is also a Lying, Congressional Style book laying beside some ammo cases and gore bags.


 * One at Hallowed Moors Cemetary. Watch out for traps, and about 6 super mutants. Don't forget to grab the second Keller Family Transcript while you're there.


 * A captive is at Mason Dixon Salvage surrounded by about 8 mutants.


 * Between Mason District South and Hubris Comics. There are six mutants, beware of the cars which might accidentally kill the captive.


 * Where the highway enters the eastern side of DC. It is easiest to walk from Friendship Heights to Farragut station, hugging the city walls. The captive is guarded by a Mutant and Centaur. If you continue west you will find a small blockade with two mutants and a centaur, and a few gore bags. A mini nuke, two first aid kits and ammo boxes are in this blockade.


 * There are two captives at Clifftop Shacks which is almost due north of Minefield and west of Vault 92. The Super Mutants see you coming and therefore come to meet you, so it's easy to dispose of them without hurting the captives. However, this area may become a battle site between Raiders, the Brotherhood of Steel Outcasts and the Super Mutants.


 * There are two captives in the Roosevelt Academy escape tunnels and maintenance section. If you release the captives before you completely clear the area of super mutants and centaurs, they will likely be killed in their escape, but you will not suffer any karma penalty if that happens.


 * There is a Captive to the North of Anchorage War Memorial, where the fifth Keller Tape is. The captive is in the tent behind the trucks, guarded by a Super Mutant armed with a Super Sledge and two centaurs. Warning: Do not shoot the trucks or you will kill the captive. Assuming you have followed the Wateland Survival Guide quest early on, this should also be your first encounter with a Super Mutant. The event seems to be scripted so that the Centaurs attack you first, and as you make your way up the hill to the tent, the Super Mutant emerges slowly wielding a sledgehammer. This is likely to startle you with its emmense size.


 * A random encounter can occur wherein two Super Mutants are holding a Captive for you to rescue.

Reward
If you free the captive, they will thank you and offer some supplies, such as dirty water, rad-x or ammo. If you accept these supplies, you will receive 50 karma points and the supplies. If you tell them to keep it, you will receive 75 karma. There is no karma penalty for leaving the captive to their fate.

Bug
A captive was rescued near Rivet City. After that, he appeared in front of The Citadel. The Brotherhood of Steel Knights and Paladins shot him. (confirmed bug on Xbox 360 version)

Perhaps not a bug, but an interesting twist. I released the captive by Rivet city, he then proceeded to pick up a Minigun and hunt down all of the super mutants around the Jefferson Memorial.

A captive may, at times, not have ropes around their wrists while still acting as if they do.