A Vigilante is a Townie who can kill a player at Night.
Using traditional flavors, Vigilantes share the "shot" kill flavor with the Mafia. Thus, their kills are indistinguishable from those of the Mafia in this case.
While a few moderators prefer to defy meta and use Mafia Vigilantes to allow multiple scumkills from a single faction, the vast majority of Vigilantes are Town.
There is no consensus as to whether "Vig" is pronounced with a hard 'g' or like "Vidge". The easiest solution to this problem is to pronounce it however you like, but never try to make a pun out of "Vig" or try to verbally say it to others.
This role is can typically only be used a limited number of times per game. These are called X-Shot Vigilantes (where 'X' can be replaced with the number of times they can kill over the course of the game).
There is no consensus in regards to whether an X-Shot Vigilante loses one of its ability uses if it is Roleblocked while trying to kill someone.
In games with nontraditional kill flavors, it is by no means a requirement for the vigilante to have a kill flavor indistinguishable from that of the Mafia.
One of the most coveted variations of this ability is the Dayvig, which is a Vigilante that can kill during the Day. Depending on the game, the Dayvig may be able to submit its kill privately, or it may be forced to declare its kill publicly. Daykills are not normally stoppable by active abilities, so Dayvigs are considerably more potent than ordinary Vigilantes.
The Mad Monk variation is a Vigilante that can not be killed at night
The Crazy Fiend Variation is a one-shot Vigilant that is scum or anti-town aligned.
The Arsonist variation is functionally similar to a Vigilante.
Vigilantes are considered Normal on mafiascum.net if their kill flavour is indistinguishable from other factions'. As of 9 November 2015, they must also be town aligned.
Use and Power
Vigilantes simply increase the death count and thus the speed of the game. While in theory Vigilantes constitute additional Town-sourced kills, in practice Vigilantes vary widely in skill and effectiveness. Considering the difference between a Vigilante that only hits Townies and a Vigilante that only hits scum, it's easy to see that this is one of the swingiest Normal roles.
Because of its swingy nature, it's hard to judge a Vigilante's power in terms of whether it weights the game in favor of Town or scum. At present, Vig is considered a fairly solid pro-Town role due to adding another Town-directed kill to the game (contrast scum-directed kills, which have no chance at all of hitting scum). In addition, Vigilante is generally a very confirmable role - not many roles kill people aside from the Mafia's factional kill, so after an unexpected extra player dies a Vigilante can claim the kill. Since Vigilantes are almost always Town, the Vig is generally considered confirmed Town from that point on. Dayvigs are even more confirmable as Vigs for obvious reasons, but on occasion moderators have been known to include scum dayvigs.
As a final note, generally when given the choice between being able to kill someone or being able to do almost anything else, players will choose to kill someone. Balance your games accordingly.
The philosophy of when and how often a player should shoot is debatable. One school of thought is that kills narrow down the pool of suspects, so any player that is not less likely to be scum than random should be fair game for being shot. This same school of thought favors killing on every Night, including Night 0 (when there is no game-related information about any player).
The other school of thought is that Vigilante kills take away majority-rules lynches from the Town, placing too much power in one player's fallible hands. This school of thought advocates only shooting players who are likely to be scum (or even whoever the Town collectively dictates should be shot), and not shooting otherwise.
The best play as a Vigilante is to shoot scum. This requires the Vig to find scum. There is no easy way to do this. However, because of their ability to make or break entire games depending on who they target, Vigs are frequently lauded and/or blamed for their decisions beyond appropriate proportions. Thus, as a Vig your best bet is to make decisions that will not cause you to be hated by every other player in the game. If in doubt, shoot a player that people would want to policy lynch (e.g. lurkers).
Another potential approach to playing a Vigilante is to attempt to predict what the most likely lynch the next day would be, and shoot that player; if they're scum, great, if not, you effectively denied scum the nightkill they'd get after the mislynch tomorrow and so you're still helping. This effectively introduces the Double Day mechanic into the game.
Sample Role PM
- Welcome, [Player Name], you are a Town Vigilante.
- Each night phase, you may attempt to kill another player.
- You win when all threats to the town have been eliminated.