Mesmetron

The Mesmetron is a Fallout 3 weapon that is used in the quest Strictly Business, and is given to you by Grouse (the Paradise Falls entrance guard) when you start the quest.

Characteristics
When used on the specified quest NPCs, it puts them into a hypnotic stupor, allowing the player to rob and enslave them (by putting a Slave Collar on them) and send them to Paradise Falls. It also appears to work on some other NPCs, but often simply sends them into a berserk frenzy in which they become hostile towards the player and every other NPC in the area. Occasionally, the victim will run several steps before their head explodes.

The Mesmetron has a 50% chance to mesmerize an applicable target, 30% chance to cause frenzy, and 20% to explode their heads. If the target can't be mezzed, the chance to cause berserk is 80%.

It uses Mesmetron Power Cells as ammo. You start out with 50 Mesmetron power cells. Grouse will also sell you additional power cells, but at a fairly high price (200 caps for 10 Power Cells).

If you don't want to take the Strictly Business quest, you can obtain the Mesmetron by killing Grouse and looting his corpse. You have to kill him to obtain the Mesmetron, as it cannot be pickpocketed. If you kill Grouse, the Mesmetron can only be used for robbing or frenzying NPCs, as you cannot enslave NPCs with Grouse dead and Paradise Falls hostile towards you. You also cannot obtain additional Mesmetron power cells from anyone other than Grouse.

Background
The Mesmetron is an experimental pre-war "non-lethal pacification" weapon that was being tested in the months immediately preceding the nuclear war. It operates by sending a signal pulse into a human target's brain that scrambles higher-level mental functions, leaving the target extremely susceptible to suggestion. Still in its testing phase, the weapon was found to have the potential to trigger two undesirable side-effects... 1) extremely increased aggression, or 2) "spontaneous cranial eruption".

Grouse found it in a pre-war military installation, and gives it to the player character for field testing if they accept the Strictly Business enslavement quest from him.

=Notes=
 * Raiders can be rendered "Friendly" by mezzing them and then removing the Slave Collar. A female raider, mezzed at Springvale School was seen to run several kms south then stop.  Once the collar was removed (high science skill required), the raider's map compass blip and health bar stayed green, and she was heard to give positive grettings to the PC, though no dialogue options existed. After fast travel to other location and a return to Springdale Elementary, the 'friendly' raider was seen to have returned to the school from the far south of the map as was still non-hostile to the player.


 * If the "Cranial Explosion" side-effect mentioned above occurs when you tried to mesmerize a town member, the whole town becomes hostile. This is extremely bad when you're trying to mesmerize a shopkeeper to get their store keys off of them, and saving before attempting this is recommended so that you can try turning them hostile again if they experience cranial explosion.
 * It's best to have your followers wait somewhere else while using the Mesmetron for slaving as they may slaughter the slave when they flash hostile.


 * Sometimes, when you shoot someone in the head with the mesmetron, they will attack you, making other NPC's attack them. This can give you keys to merchandise if they're store keepers.


 * Mesmerable targets are based on a faction list of 672 members, filled mostly with generic NPCs (making it difficult to sort and list named NPCs.) NPCs set to essential are immune.


 * There's a shorter faction list of NPCs who can always be mezzed, and this initially includes the four objectives of the Strictly Business quest and one generic leveled slave.


 * After an NPC is successfully mezzed, it is added to a faction list that can never be mezzed.
 * The mesmetron works well on almost all caravan guards and mercs, except Talon Company Mercs or any member of Reilly's Rangers.


 * Good if you want to kill someone in the middle of a city without causing a scene. It allows the player to attack his/her target without fear of retaliation. It is an effective "stealth" kill, because the person will begin shooting everyone for "no" reason, and you will be unblamed, even if done outside of sneak-mode. If you decide not to take action, the "mezzed" person will likely be killed by other NPCs.


 * Upon exploration, it appears that the Mesmetron successfully mesmerizes more than the four NPCs targeted in Strictly Business and generic NPCs. Most named characters that are not listed as targets in Strictly Business cannot be made into slaves. Due to bugs or by design, both of Dukov's companions, as well as Christie Young and Angela Staley from Rivet City are susceptible to the Mesmetron.


 * This can be used successfully to re-enslave the escaped slaves at Temple of the Union, even though they are named NPCs.


 * The frenzy side-effect is quite useful when certain NPCs won't leave an area or just rub you the wrong way. It's been shown to be ineffective on all shop keepers, trade quest subjects, or owners of some unique items. However, some caravaners or wastelanders, as only in-game traders, are mesmerable. It can also be used to turn people against each other. This can be very useful in the Rescue from Paradise quest if you're planning on rescuing Rory and the other slaves. Just shoot a couple of slavers in the head with the Mesmetron they'll make your job much easier.


 * It is even possible to earn decent XP with the aforementioned glitchy nature of the device. After having someone go berserk, simply run away from them to gain some distance while they battle whoever is within their sight, snipe them away with a long-range weapon while sneaking and don't get near their corpse for a short amount of time, remaining hidden if possible. There's a good chance the townsfolk - or any other member of a friendly faction who you don't want to antagonize for the time being - will simply remain indifferent to what you have done. You may try initiating "wait" right after the kill to increase your chance in some occasions. It is possible to wipe whole towns clean with this glitch.


 * Occasionally, instead of going berserk, unenslaved targets will despairingly wail, "It's hopeless!" and run away. They will still be hostile to the player, however.


 * It appears that unarmed (or disarmed) NPCs are more likely to be enslaved by the Mesmetron. Attacking an NPC's weapon or arms and then switching to the Mesmetron may be the optimal tactic for enslaving raiders and other generic NPCs.


 * The effect of Mesmetron is not absolute - the effect is different every time. When saving and loading the game, and using the Mesmetron again, the effects vary.


 * It appears that the Mesmetron has a slimmer chance of working on targets that are already hostile towards you, even those that are normally mesmerable. Do not expect the Mesmetron to aid you in escaping a confrontation.


 * If you attempt to use the Mesmetron on an NPC who is sitting down, there is a chance their body will spin like a top in the seat before their head explodes. Chief Gustavo in Tenpenny Tower while sitting at the desk is a good example of this.


 * Fallout 3 will keep track of how many characters that you have "mezzed". You can access this information with your Pip-Boy.


 * Female raiders are easier to mesmerize than their male companions(assuming you are a male, opposite for females).


 * From time to time a mesmerized and collared target won't make it to Paradise Falls, this causes the collar to be lost and as no slave was turned in, the collar must be re-purchased from the slavers.A slave's sucess rate seems to be based on armor equipped so it may be necessary to give them some armor.


 * The Mesmetron can be used to turn enemies into allies. After successfully Mezzing a character and putting a slave collar on them, tell them to run to Paradise Falls, but as soon as the dialog ends run up to them and talk to them again before they run off. They will ask you to remove the collar; you can do so using sufficient Science or Explosives skill. Once the collar is removed, the formerly Mezzed character will become your ally (as they are now members of the "escaped slave" faction).
 * They will usually remain neutral towards their former friends (i.e. a Mezzed Raider will ignore other Raiders, but at least won't object to you killing those Raiders). However, they will definitely fight against monsters (i.e. critters and Deathclaws). Note that Mez-befriended hostiles (i.e. Raiders or Enclave Soldiers) will remain hostile towards civilians, and will attack any Wastelanders or NPCs that cross their path.
 * Enslave a respawning Raider (such as those at Bethesda ruins), but instead of freeing them tell them "you're a slave, deal with it", then proceed to kill them. When they respawn, they will be armed but "friendly" - you can walk up and speak with them, but they will tell you off. Possibly useful in a zone such as Bethesda Ruins where as soon as you fast-travel you are swarmed by respawning hostiles.


 * The Mesmetron can activate the Mysterious Stranger perk. Surrounding friendly NPCs will not become hostile even if this results in the death of your target. Usually when this happens, the Mysterious Stranger does not attack even though he shows up.


 * If the Mesmetron is used on a freed Super Mutant captive they will appear dizzy as they normally would, but you do not have the option of talking to them.


 * The Mesmetron also works on Grandma Sparkle in Wilhelm's Wharf, Paulie Cantelli in Rivet City, Brock in the Muddy Rudder, Trinnie in the Muddy Rudder, Henry Young in Rivet City, and Tammy Hargrave in Rivet City.


 * If you get the Contract Killer perk, then mezz your father, James, you can pickpocket him and get an ear.


 * Enslaving Underworld Residents while 'Hidden' [not even requiring a Stealthboy] is a good source of amusement and income, noting of course the comments made above.


 * The Mesmetron works on Enclave Soldiers (xbox 360 but possibly on other consoles).


 * After attempting some 20 times it appears Rivet City guards are immune.


 * There have been reports of the mesmetron setting off gas leaks.

Trivia

 * The Mesmetron is similar in both name and effect to the Persuadertron from the Syndicate game series. The Persuadertron, however, allows complete domination over a victim without the need of a Slave Collar.
 * Similar to the L.O.O.K.E.R. (Light Ocular-Oriented Kinetic Emotive Responses) gun, a light pulse device that gives the illusion of invisibility by instantly mesmerizing its victims into losing all sense of time.
 * The method of operation is also similar to a Star Wars expanded universe device called the Gun of Command, an EMP weapon that is used by the matriarchal Hapan nation in executions.

Appearances
The Mesmetron appears only in Fallout 3.