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Mesmetron: Misc



Up to date as of February 01, 2010

From The Vault

Attack statistics
dmg/attack: 1
DPS: 1.0345
attacks/sec: 1.0345
# of projectiles: 1
spread: 0
other effect: see article
crit dmg: 0
crit chance: x 1
ammo type: Mesmetron Power Cell
ammo per shot: 1
ammo capacity: 5
shots/reload: 5
skill: Energy Weapons
AP: 65
item HP: 100
repair: Merchants
weight: 2
value: 500
base id: 00004339

The Mesmetron is a prototype stun gun in Fallout 3.



The Mesmetron is given to you by Grouse, the Paradise Falls entrance guard, when you start the quest, Strictly Business.

If you don't want to take the 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 pick-pocketed. If you do this, you cannot get a Slave Collar and thus can't enslave NPCs (however, enslaving them would be pointless anyway in this case since there will be no Grouse to pay you). You can still use the Mesmetron to frenzy or stun and rob NPCs.

Unless you killed Grouse, he can provide you with additional Mesmetron power cells, but at a fairly steep price.


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 many other NPCs (aside from quest related ones), but can simply send 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.

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). An additional 38 Mesmetron Power Cells can also be found in the Underground Lab in the Point Lookout DLC.

Using the Mesmetron

As previously mentioned, using the Mesmetron on an NPC can have 3 different outcomes. These effects vary and are generally unreliable, so it is advised to save before using this weapon on anyone important. Due to the fact that using the mesmetron is considered assault, it is advised to "mez" someone while not detected (Stealth Boys and the Chinese Stealth Armor will come in handy here). Be aware that mezzing anyone who is already wearing a Slave Collar will cause the collar to malfunction and explode, killing the victim. Hostile NPCs who were mezzed can also be turned friendly by being freed by the player (high Science skill required). An analysis of the Mesmetron's effects:


Mesmerize/Stun (50% Probability)

This first effect stuns the victim for a few seconds, during which they stand still and their heads sway from side to side. When the victim is stunned, it is possible to engage in conversation with them. Note that some characters cannot be stunned, in which case the probability of the Frenzy effect is raised to 80% to replace stun.

While in conversation, you will first have 3 options. The first option convinces the character to allow you to take their things (by either telling them it's a magic trick, that there is a thief on the loose, that you think they stole something from you, or by just telling them to give you their things) which will open up their entire inventory (even the items they are wearing/using) and allow you to take or even add any item. The second option slips a Slave Collar on the character (instantly netting the player negative Karma regardless of who the victim is). The final option simply tells the victim to "walk it off"; this will exit the conversation and make the character resume what they were doing (presuming you haven't made any onlookers hostile).

A Raider stunned by the Mesmetron

The second set of dialogue options (unlocked by slipping a collar onto the victim) is quite simple. The first option is the "cruel" way to inform the victim that they are now a slave ("...your head will explode!"). The second option once again allows the player to check their inventory, and the third option is the slightly nicer way to inform them of their "new occupation" ("...nothing personal").

If the character is not talked to before their stun wears off, they will become hostile.

Frenzy (30% Probability)

This second effect causes the victim to go into a state of frenzy, attacking anyone nearby (most likely the player), and causing all other characters to turn on them. The onlookers may also become hostile to the player if he is seen stunning the victim. This method can also be a reliable way to get rid of victims without attacking them or getting negative Karma. You can die from this, especially if one of your enemies has any high-damaging weapons.

Spontaneous Cranial Eruption (20% Probability)

This final effect of the Mesmetron may not be the most useful, but is definitely the most spectacular. If a victim is affected by the Mesmetron in this way, they will become hostile (and either run, stand still, or attack) for just a moment before their head literally explodes. This effect will instantly get the player negative Karma (if the victim was good/neutral) and make any nearby NPCs who were not hostile to the victim become hostile to the player.


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.


  • 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.
  • Enslavable 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 may be 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.
  • To enslave someone, you must have a slave collar, which you can only have one at a time... usually.
    • You can get as many collars as you want. All you have to do is enslave someone, follow them to Paradise Falls, talk to Grouse to get your caps and a collar. Then quickly catch up to the slave and talk to him/her, and say "You're a slave, deal with it" or something like that. Now all you have to do is go back to Grouse again to get 250 caps and another collar! You can only do this once per slave though because you can never catch up to the slave a second time. (Unconfirmed) . Keep in mind though that enslaving multiple NPCs at once won't net you lots of caps and collars because Grouse only pays you for one slave at a time.
    • Only one person may be mezzed at a time.
  • After an NPC is successfully mezzed, it is added to a faction list that can never be mezzed.
  • 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 game will keep track of how many characters that you have "mezzed". You can access this information with your Pip-Boy.
  • 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 success rate seems to be based on armor equipped so it may be necessary to give them some armor.
  • 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. Better yet disarm the collar and get it back. They'll still respawn as friendly and you don't have to pay for a new collar.
  • 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. When this happens, the Mysterious Stranger may not attack when he shows up, but has been recorded killing targets with 150 health or less.
  • 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.
  • If the Mesmetron is used on an unfreed captive and they are then freed then the captive will appear dizzy as they normally would, you will not have the option of talking to them and they will return to their tied-up position when the effect wears off. You will then be unable to interact with them again (except to mezz them more or kill them).
  • If you get the Contract Killer perk, then mezz your father, James, you can pickpocket him and get an ear.
  • "Mezzing" someone who is seated or lying down may cause them to spin rapidly in place before their head explodes.
  • Generic NPCs (such as Raiders) who are enslaved and successfully sent to Paradise Falls will not respawn. Significant use of the Mesmetron in a specific area can therefore permanently clear that area of human enemies.
  • "Mezzing" anyone in the citadel laboratory will automatically frenzy them (after the quest "The American Dream"). Also, any witnesses will not turn hostile to the player.
  • One can use the Mesmetron on all generic ("healthy") human enemies, ranging from Raiders to Enclave Soldiers. It is likely that the likelihood for the different effects are altered to make the effects less powerful. From several trials on Enclave and Enclave Hellfire soldiers, it seems that the likelihood of an "exploding head" instant-kill is still around 20%; the chance of a "stun mezz" that allows conversation is around 20% also; and the remaining 60% is mainly a "does nothing" result, with possibility of a "frenzy" although it is difficult to tell. With a stun mezz, it is possible to enslave the enemy (which *will* make all other enemies attack and kill him), or to remove their armor/weapons and then let them go free and naked using the bottom conversation option, which also incurs NO Karma loss.
  • Curiously, if you enslave an evil character like a Raider, you get negative karma even though one would think that enslaving people who kill others for fun would be a good thing. This is probably because, as Three Dog proclaims, "the selling of live human beings is completely fucked up!" No matter who the evil character is or however bad they are, you will still get negative karma for some reason.
  • If you attempt to "mezz" Colin Moriarty he will simply go unconscious for a few seconds. Once awake he will become hostile.
  • If you manage to persuade Cherry to leave Dukov, you can enslave her right in front of paradise falls and watch her go inside.

See also


The Mesmetron appears only in Fallout 3.

Weapons of Fallout 3

This article uses material from the "Mesmetron" article on the Fallout wiki at Wikia and is licensed under the Creative Commons Attribution-Share Alike License.


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