This is a large list of all roles that have been used in rounds of mafia. If you think there is something that should be added, post and tell me and I'll update the list.
Vigilante ~ Can kill one person per day.
Detective ~ Can find the guilt or innocence of one person per day.
Insane detective ~ Can find the guilt or innocence of one person per day, but gets opposite results. Is told they are a regular detective.
Rookie detective ~ Can find the guilt or innocence of one person per day, but always gets innocent results. Is told they are a regular detective.
Jaded detective ~ Can find the guilt or innocence of one person per day, but always gets guilty results. Is told they are a regular detective.
Roleblocker ~ Can stop someone from using their special.
Elder ~ Gets two votes the second is PM'd to the host.
Hobo ~ Is told they are elder. But second vote actually subtracts one.
Doctor ~ Can save one person per day from being killed, cannot save someone from a lynch (may change depending on some hosts).
Schitzo ~ Picks one person per round to randomly protect, roleblock, murder, or investigate. If they investigate they will receive accurate results but not until the kill post.
Granny ~ If anyone targets this person the granny will shoot them. The Godfather/mother can successfully kill the Granny if sent for the kill. Sometimes called the Paranoid Gun-Owner.
Head Mason ~ Leader of the masons. A group who know all of eachother. Can recruit one mason per round. If he/she attempts to recruit a role that is not village, they are killed.
Mason ~ Normal mason, recruited by head.
Townie ~ Normal, no special.
Miller ~ Normal townie, but appears guilty to investigations. Is told they are a regular townie.
Bodyguard ~ Can protect one person per round. If someone tries to murder them the bodyguard dies in their place. Cannot protect themselves.
Elite bodyguard ~ " " They also take out the killer.
Neighborhood Watch ~ May watch one person each night, finding out who targeted them that night.
Stalker ~ Able to watch one person each night, finding out who they targeted that night.
Governer ~ Can stop a lynching for anyone except themselves. They cannot stop a lynching for the same person twice in a row. And, they can stop all specials for a night once per game. They cannot stop their own lynch, but they can still stop all specials for that night.
Lie Detector ~ Chooses one post from a person every day and sends it to the Host to check if what is said is true, it can not test a role-claim. For example: "I am the Doctor". Or, "So-and-so is mafia".
Priest ~ If lynched, the people are horrified and instead, lynch the first person to accuse the Priest. The Priest's role then becomes known to all. If the Priest attempts to create a paradox by being the first person to vote for themselves, then instead the second person is lynched.
Inventor ~ Can use a different device every night, the standard ones used are investigation, roleblock, protect, kill, and a random one. In some rounds, once a device is used it cannot be used again until all of the devices have been used.
Firefighter ~ Is the only person that can protect someone from Arsonist kills, if he targets the Arsonist, then the Arsonist dies.
Juliet ~ Renamed from Good Brother. Lover to Romeo in the mafia, knows who Romeo is. If Romeo dies, then Juliet kills herself. Protection can't stop the suicide.
Hider ~ Hides behind one person every night. If something happens to their target, it happens to them as well. If their target is investigated, the investigator gets results for both their target and the Hider. If the target is killed, the Hider dies too. But while they are hiding, they are ineligible for any actions, cannot be directly killed or investigated or etc. In some versions, the Hider dies if they target a non-town.
Alarmist ~ A form of protective role designed to counteract a Cult Recruiter. The Alarmist targets a player, and if someone else attempts to recruit that player that Night, the recruitment will fail.
The Imposter ~ Targets one person a night to "steal" their special for the night. The next night, they can then use that special while their target won't be able to. Then the next night their target gets their special back and they pick another person. They cannot target the same person twice (unless everyone left has been picked already)
The Silencer ~ Silences one person a day. That person can vote and PM if they are allowed to, but can not otherwise participate in discussion. They are allowed to mention the next day they were silenced if they so choose. Can not be used on the same person twice. (unless it has been used on everyone already). The silencer's role is in effect as soon as the host reads the PM. Could work as a role in any faction.
Godfather ~ Decides and submits the mafias kill and also which member will be delivering the kill. If he/she dies, a new Godfather is selected. In some host's rounds, the Godfather/mother appears innocent to investigations.
Snitch ~ Can investigate one person per day to find out their EXACT role.
Prostitute ~ Can stop one person from using their special per day.
Henchmen/Grunt ~ Normal mafia member.
Janitor ~ If sent for the kill, prevents the town from knowing the role of the mafia's kill. Janitor is told after their victim's death.
Surgeon ~ Can protect one person, does not have to be a fellow mafia member.
Sniper ~ Can get one extra kill for the mafia every two nights. The number of nights between kills sometimes varies, but it is most often two.
Accountant ~ Can subtract a vote from someone.
Romeo ~ Renamed from Bad Brother. Lover to Juliet in the village, knows who Juliet is. If Juliet dies, then Romeo kills himself. Protection can't stop suicide. Can choose to tell his fellow mafia who Juliet is.
Serial Killer ~ Can kill one person per day. Wins if they are the last one.
Arsonist ~ Kills one person each day. Wins if they are the last one left. Only the firefighter can protect from Arsonist murders.
Bus Driver ~ Switches around two people. Whatever happens to person A happens to person B. Takes effect as soon as submitted. If someone investigates person A after the bus driver has switched him with person B then the investigator will get results of investigating person B instead. (still told they investigated person A) If they change their target to someone the detective didn't target, then the detective will recieve a PM right before the kp with their actual result. This role cannot technically win the game, but they will be declared with the winning team if they are still alve.
Taxi Driver ~ Picks two people to swap actions, whatever person A does it will appear as if person B had done it. For example, if sent in before a detective (person A), person B will recieve their investigation results. If the serial killer (person A) tries to kill someone, but the elite bodyguard protects them, then person B will be killed. This role cannot technically win the game, but they will be declared with the winning team if they are still alive. As it could reveal information about players, this role is silent in kill posts.
Jester ~ Their goal is to get lynched. Loses if killed any other way. In some rounds, their ability to win once lynched is not active until a certain round.
Bomber ~ Blows up if killed, taking two random people with him.
Grudge-Bearer ~ Renamed from Hateful Killer. At the beginning of the game, selects three people to get killed. Is told their exact role. Wins if all three die before he does. They can do nothing to kill them except to try and convince people that their target's should die.
Survivor ~ Wins if he survives to the end of the game.
Cult Leader ~ Can recruit one person to the cult each day. Wins if the cult gains a majority over the rest of the players. In most rounds, they die if they attempt to recruit a mafia.
Cultist ~ Someone who was recruited to the cult. It varies in each round whether the cultist keeps their original role or not.
Bonnie and Clyde ~ Two people who don't know who each other are, and aren't able to PM. They each send a kill, if they pick different people then nothing happens. If they pick the same person then that person dies and protection will be unable to prevent this. They win if they outnumber the rest of the players (one other person left.) They also cannot be roleblocked, and if one of them dies, the other will suicide.
Sometimes, mafia rounds will be off the wall where completely new roles and twists will be used. Summer's Atlantic City round includes a slot machine twist, as well as roles that have advantages with the slot machine. Mafia XLVI. Nortac has done two rounds with Werewolf instead of mafia, the werewolves have the ability to add members to their pack. Mafia VII.
Things that are often varied between hosts were underlined, as well as names I changed (Good/Bad brother, Hateful Killer). Again, if there are things you think should be added/changed, please PM me in a complaining tone about it and I will probably edit it in unless it's a dumb idea.