Mafia (party game)

"Mafia (game)" redirects here. For the video game, see Mafia: The City of Lost Heaven.

Mafia

Designers	Dimitry Davidoff
Players	At least 6 or 7, ideally 9 or 11
Age range	12 and up
Skills	Strategic thought Team play Social skills Roleplay

Mafia (Russian: Ма́фия, also known as Werewolf, Assassin, Witch Hunt, Palermo Nights or Pirates) is a party game created in the USSR by Dimitry Davidoff in 1986, modelling a battle between an informed minority (the mafia) and an uninformed majority (the townspeople). Players are secretly assigned roles: either mafia, who know each other; or townspeople, who know only the number of mafia amongst them. In the game's night phase the mafia covertly 'murder' a townsperson. During the day phase, all of the surviving players debate the identities of the mafia and vote to eliminate a suspect. Play continues until all of the mafia have been eliminated, or until the mafia outnumber the townspeople. A typical game starts with seven townspeople and two Mafiosi.

History

Dimma Davidoff (Russian: Дми́трий Давы́дов, Dmitriy Davydov) is generally acknowledged as the game's creator. He dates the first game to spring 1986 at the Psychology Department of Moscow State University, spreading to classrooms, dorms, and summer camps of Moscow University. Wired attributes the creation to Davidoff but dates the first game to 1987, with 1986 being the year in which Davidoff was starting the work which would produce Mafia. He developed the game to combine psychology research with his duties teaching high school students. The game became popular in other Soviet colleges and schools and in the 1990s it began to be played in Europe and then the United States. By the mid nineties a version of the game became a Latvian television series (with a parliamentary setting, and played by Latvian celebrities).

Andrew Plotkin gave the rules a werewolf theme in 1997, arguing that the mafia aren't that big a cultural reference, and that the werewolf concept fit the idea of a hidden enemy who looked normal during the daytime. Although the game can be played with a deck of poker cards or slips of paper, Looney Labs successfully marketed a commercial version of the game as Are You a Werewolf?, which was later followed by Asmodee Editions under the title Werewolves of Millers Hollow, Mayfair Games as Lupus in Tabula and Bezier Games as Ted Alspach's Ultimate Werewolf: Ultimate Edition. A Cthulhu Mythos variant (Do You Worship Cthulhu) was published in 2006.

Mafia and a variant called Thing have been played at science fiction writers' workshops since 1998, and have become an integral part of the annual Clarion and Viable Paradise workshops. The Werewolf variant of Mafia became widespread at major tech events, including the Game Developers Conference, ETech, Foo Camps, and South By Southwest.

In 1998 the Kaliningrad Higher school of the Internal Affairs Ministry published the methodical textbook Nonverbal communications. Developing role-playing games 'Mafia' and 'Murderer' for a course on Visual psychodiagnostics, to teach various methods of reading body language and nonverbal signals.

A variation of Mafia was used to promote the film Cry_Wolf (2005), having one wolf and a number of sheep, with the computer acting as shepherd. Writer Adam Gopnik described playing weekly Mafia games in New York City in Through the Children's Gate.

In March 2006 Ernest Fedorov was running a Mafia Club in Kiev, using his own patented variation of the rules. The club organizes games, rates players, and awards prizes (including a Sicily trip for their tournament-series champion).

In June 2006, a Rockingham school inquiry was launched after parents complained of the traumatic effects classroom Mafia was having on their fifth-grade children.

Mafia was called one of the 50 most historically and culturally significant games published since 1800 by about.com.

Basic gameplay

One person is the game's Narrator - who moderates the game, rather than participating. Everyone else is dealt a card that gives them their secret role as a player.

Basic roles

• Two or more Mafia (who win by killing off or outnumbering civilians)
• One Detective (a Civilian who can inspect players in the night as to whether or not they are a mafia)
• One Doctor (a Civilian who can elect someone to save in the night)
• A number of Civilians

Andrew Plotkin recommends exactly two Mafia players, while the original Davidoff ruleset suggests having a third of the players (rounding to the nearest whole number) being Mafia. Davidoff's original game does not include a "Doctor" or "Detective" role.

In his rules for "Werewolf", Andrew Plotkin recommends an odd total number of players, to prevent ties during lynch votes, and to ensure that the game ends dramatically on a lynching, rather than with an anticlimactic murder. An even number of players would also weaken the civilian team, who will always suffer one extra murder.

Night

The Narrator tells everyone to close their eyes ("It is now nighttime and everyone in the city is asleep..."). The Narrator then asks the mafia players to open their eyes and acknowledge their fellow members. They agree to kill off one of the other players by silently gesturing to indicate their target and to show unanimity. Then the Narrator instructs the mafia members to "sleep", by closing their eyes again.

Next, the Detective is asked to open his or her eyes and point at a suspect; if that player is mafia-sided, the narrator nods. Then the Narrator instructs the Detective to sleep and the Doctor to open his or her eyes; he or she points at someone to save, then goes back to sleep.

The night phase can optionally be accompanied by players tapping gently to mask any small, giveaway sounds made by the Mafia players gesturing.

Day

The Narrator tells everyone to wake up. Unless the doctor and the Mafia selected the same target a murder is announced, sometimes with a little narrative detail. (For example, "David was shot seven times, stabbed three times, and drowned in the river.") This player is "dead" and may no longer participate in the game in any way.

During the daytime phase, the players deliberate over which suspected Mafia member they wish to nominate for lynching. Once nominations are made, the narrator administers an election between the nominees, in which all players vote - whoever receives the most votes is lynched; they are dead, and may no longer participate in the game in any way. The role of the lynched player, whether mafia or citizen, is not revealed unless it were to result in ending the game.

Because players have less information and more freedom to deliberate during the day, the day phase tends to be longer than the night phase. The day phase either has a set time limit, or continues until a lynching has been performed.

Win condition

If all Mafia members are killed, then the Townspeople win the game. If the villagers are outnumbered by the Mafia during the day, then the Mafia win.

Variations

Naming for the various roles, factions, and other elements of play is theme dependent and has limitless variation. Common themes involve the Mafia players being restyled as Werewolves, Worshippers, Assassins or Witches, with other roles being renamed appropriately.

Variants may introduce additional night-time phases, allowing special-role characters to do business during the night, either before or after the Mafia.

In some variants, the Narrator may conceal the role or alignment of killed players, or allow killed players the choice of revealing their own card.

Optional roles

These additional roles are named differently in the many versions of Mafia, for thematic flavor, or historical reasons. Also, the same role-name can have differing functions across different versions of the game. What follows is a general list of role types found in Mafia variants; since the specific names vary by milieu it must be non-exhaustive.

Investigative roles

Players with these roles use their own night-phase to discover something about other players. Though the standard game now includes the basic Detective, these roles are optional, and games can exclude them entirely (such as the stool pigeon variant, or Davidoff's original rules).

Investigative roles (standard)

• —Detective, Seer, Commandant, Sheriff, etc.

Allied with the Innocents, the Detective can detect whether a player is a mafioso. They will typically wake up, and point at one person; the Narrator will silently indicate to the Detective whether that player is Mafia or Innocent. In some versions of the game, the Detective's investigation result is announced publicly by the Narrator, for example the Detective found a Mafioso!. More commonly, no announcement is made. As with other roles, which player is the detective is not generally known, leaving anyone the option of pretending to be the Detective.

A Detective is usually included in modern games. For example, somebody is always assigned this role in all commercial card game versions, and almost all internet-based, and most face-to-face games start with at least one detective. Multiple detectives either act in separate night phases (unaware of the identities of other detectives) or work together as the police (an association role).

Investigative roles (less common)

• —Psychic, Wizard, Fortune Teller, Oracle, etc.

Psychic, Psychologist, or Sorcerer-type investigators can determine other players' roles, rather than their alignments. Roles which detect other roles are usually implemented in the same way as the Detective's ability to determine alignment. For example: the Psychologist points to a player (at night) for a Thumbs-up from the moderator if the Vigilante is pointed to. A Tracker may see what someone's night action was, or the target of their action.

Information revealed to investigators is fallible (in more complicated variants). Online versions can give information with a confidence level, and in other variants the Narrator deceives the Detective by showing all players as Innocent, all as Guilty, giving reversed results, or random information (these can be termed as Naive, Paranoid, Insane, or Random respectively). Additionally, some Alignment roles give immunity to successful investigation.

In some games, there are Mafia Detectives, who have the power of a normal detective but are on the Mafia side. The Super Commandant has the standard power of a Detective, while also protecting the investigated from night-time attack.

Omniscient roles

• —Witness, Child, Little Girl, etc.

Instead of having to investigate, some innocent roles give complete information on the entire mafia: The witness is told who the mafia are during the first night, while the mafia are not told the witness's identity (differing from the stool pigeon in not being a part of the mafia).

The Little Girl in Werewolf and Werewolves of Miller's Hollow is allowed to secretly peek and watch as the werewolves choose their victim; if discovered doing so by the Werewolves, she dies of fright.

Protective roles

• —Guardian Angel, Doctor, Healer, Bodyguard, Hero, etc.

Allied with the Innocents, the Doctor-type role defends others at night. Typically, they will awaken at night after the Mafia have gone back to sleep and point at one person to protect; that person will survive any night-time attack. They are typically allowed to protect themselves, and are commonly barred from protecting the same target on successive nights. A Guardian Angel can only protect others. The Nurse gains the Doctor's abilities if the Doctor dies. The Firefighter, or the Herbalist can protect from some night-time attacks but not others (in Werewolf, for example, they choose one person to protect with wolfsbane, but that person may still be killed by the Serial Killer). Other games limit this ability to a certain number of times.

Killing roles

• —Vigilante, Hunter, Bomb, Woodcutter, etc.

Aside from Mafia, Werewolves, and Serial Killers (solitary guilty parties), the Innocents may have some roles with the ability to kill at night. The Vigilante is an innocent who kills every night, in his own night-time phase, in some variations, having a limited bullet supply for the entire game. Some variations introduce a time limit of two nights before the player in the Killing Role can exercise his right to kill again. The Bomb may only trigger if targeted at night (not necessarily for death) by another role. Variants exist where this person can kill during the daytime cycle (e.g., the Terrorist / Gravedigger), sometimes only if executed during the daytime. The Woodcutter or Hunter can take one other person with them whenever they die.

Alignment roles

• —Miller, Godfather, Alpha Wolf, Wildcard, etc.

Some roles can fool investigations to determine their alignments: the Miller is an Innocent who appears guilty (usually because they are an outsider); the Godfather, on the other hand, appears innocent despite being the Mafia leader. The Alpha Wolf or Master Werewolf have the same role as the Godfather in Werewolf settings.

Double-agent roles

• —Traitor, Possessed, Undercover Cop, Godfather, etc.

The Traitor is not a mafioso (in that he does not awake at night and is not revealed as a mafioso by Detective type roles), but works to protect them and hamper the town during the day cycle, and wins only with a Mafia victory. Conversely, the Undercover Cop is a mole within the Mafia group who acts with the Mafia but wins with the innocents. The stool pigeon may be the only optional role in play, and makes up one of the few modern game forms to be played without an investigative role.

Distinct from the alignment-role Godfather, the double-agent Godfather behaves as a standard mafioso, but wakes again (after the Mafia sleep) to perform an extra kill. This Godfather-role wins only if he survives.

Role manipulators

• —Role-blocker, Bus Driver, Thief, Barman, etc.

These roles can stop or alter the night actions of others; for instance, they may prevent a protection or investigation from occurring, or they may change the target. The Role-blocker can block the Vigilante for a night, while the Thief, Prostitute or Hypnotizer might be able to disable the powers of any selected target.

When the thief is used in Werewolves, an additional townsfolk card is added before dealing, and the Thief may choose on the first night to steal the role of another player or to take the unused role card. The player whose role was stolen gets the unused role card and the Thief card is discarded.

Recruitment roles

• —Godfather, Psychiatrist, Piper, Cult Leader, etc.

The Mafia Godfather may be able to recruit innocent players into his faction under certain circumstances. The Yakuza is a regular mafia player with an extra power: they may sacrifice themselves from the second night (during the night) and choose an innocent to join the mafia.

Each night, the scientist selects a player to cure; if a mafioso is cured, they awaken as an innocent. The Psychiatrist is an innocent with the ability to convert the Serial Killer into a normal innocent.

Cult Leaders recruit followers at night instead of kill; they act as an independent faction, usually with the ability to talk at night. The Piper wins by charming every surviving player; she charms players at night, who then know each other (but not the piper) but are otherwise unaffected.

Association roles

• —Freemasons (Masons), Siblings, Lovers, Police, etc.

Possessors of these roles know one another and what their roles are. On the innocent's side, a Mason usually has no special abilities, but knows the identity of all other Masons and that all Masons are also innocent. Every member of the detectives or the police knows all the rest, because they collaborate at night to investigate someone (sharing the powers of the Detective role between them).

Sibling pairs typically consist of one Mafia and one Innocent; if one dies, both die. Cupid in Werewolves chooses a pair of Lovers on the first night. In this variant, the Lovers can also win the game (regardless of whether they are Mafia, Innocents, or both) by being the last two standing. In most versions, if one Lover is killed the other dies immediately.

Election roles

• —Doublevoter, Priest, Rabble Rouser, Lawyer, etc.

Until the Rabble Rouser dies there are two lynchings per day.

In some games there are players who can change the vote count. Some players have 2 votes (Doublevoter); some players can only cast the final vote to kill a player (Actor); cannot vote to lynch (Voteless Innocent); must delegate someone else to vote for them (Fool), or require one fewer vote to lynch (Hated Innocent). The Priest cannot place the final vote (this role is not necessarily the same as the Reanimation-role priest). The lawyer selects someone during the night, and if that person tops the lynching vote the next day, saves them (a different lawyer role releases the wills written by players killed up to that point, when she dies).

Public roles

• —Mayor, Judge, Sheriff, President, etc.

This role is taken in addition to the assigned role, and it endows the player with additional, overt, powers (particularly during the daytime). Empowerment can be random, but is usually made by vote. For instance, the Mayor or Sheriff can be elected each morning, and gain two lynching votes, or a Judge could moderate discussion in parliamentary fashion (to the advantage of their team). The elected President has the sole lynching vote.

Handicapped roles

• —Murr, Village Drunk, Loon or Idiot, Teenage Werewolf, etc.

This may be a secondary role, taken in addition to the assigned role. However, it has the opposite effect, giving the bearer a handicap, like speaking only gibberish in the case of the Village Drunk, etc.

Alternatively, it may be a standard role with a particular constraint, such as the teenage werewolf, who must say the word werewolf at least once each day.

Handicapper roles

• —Silencer, Dentist, etc.

The Dentist may select any other player at night, and remove all of their teeth to prevent them speaking during the following day. The Silencer is a mafioso with the identical power, except that they may not silence the same player on successive days. The silenced individual wakes in the morning and is immediately instructed not to talk until the end of the day. They can still raise their hand to vote in live games, but being silenced in online games typically prevents any postings, including that needed to vote.

Post-mortem roles

• —Dark Background, Priest, Medium, Coroner, etc.

The dark background roles are standard (mafia or innocent) except for revealing a deceptive alignment when killed. The M.E. gathers information from the killings that can help the innocents, while the Priest learns about the alignment of the dead in the same way that the Detective learns about the living. The Medium can interrogate dead players. While the coroner survives, the narrator will explain the means of death in all night kills.

Reanimation roles

• —Reviver, Governor, Martyr, Witch, etc.

Revivers and Master Revivers are able to resurrect dead players, Master Revivers can bring the revived into their association (e.g., the Masons: see Association roles). The players resurrected by a Necromancer are converted to the Necromancer's alignment; those revived by the voodooist join a separate zombie group. The Governor can reprieve those killed during the daytime, as can the Martyr if he sacrifices himself. The Witch has a (single-use) revival potion. At night, she's shown who will die in the morning, and can choose to save them.

Rule-immune Roles

• —Bulletproof, Oracle, Elder, etc.

The Bulletproof innocent is invulnerable at night, though usually with limits; for example, the Elder will survive the first night attack, but not the second.

The Oracle has an investigative role similar to a Seer but also has the power to talk when inactive (talking in a sleep phase is usually a rule infraction).

Special roles

• —Baker, Village Idiot, Cobbler, etc.

The baker is on the side of the innocents. During the night, the baker gives one player a loaf of bread, potentially revealing his identity. If the baker dies, the innocents have just three nights to dispose of the mafia, or the innocents starve, and the mafia win. The Cobbler, Village Idiot, or Jester has the objective of convincing the town to kill him, or is required to vote in favor of all proposed lynchings. Sometimes, successful lynching of the Village Idiot results in the mafia being able to kill two people that night.

Complicated roles

Additional variations exist, sometimes with even more specialized or complicated abilities. There are endless special roles, and many moderators design novel roles for each game.

Rule variations

Over the years, players have created Mafia variants that include additional characters and rules; some of these are listed here.

Variations on the win conditions

If there are as many mafioso as innocents in the day-phase then a mafia victory is declared immediately, under vanilla Mafia rules. (Barring the use of role powers it would then be impossible for the innocents to vote off all mafia members before all innocents are killed.) Other variants suspend this rule, and only declare the game after every member of one faction has been eliminated. There are several reasons not to end the game while innocents are alive:

• It makes the game easier to explain, and run.
• The variant may have mechanics that allow the out-numbered innocents to win (e.g. via protection or resurrection of innocents, or the mafia being unaware who their teammates are).
• Or because other win conditions are in-play for certain players, and need the game to finish to be judged.

Other win conditions that may be assigned include:

• The Cupid and the Lovers variant; the Lovers can also win by being the last two in the game even if one is Mafia while the other is Innocent -in these cases the game is played until a definite outcome is reached. (Even if three mafioso and two innocents remain it is important to the Lovers which of the innocents is killed.)
• If a game has a card assigned Head Mafia or Don role, a variation has the Innocent members win when they vote successfully for the execution of the Don, regardless if there are other surviving Mafia members remaining.
• The Survivor is a neutral player, and wins when any other team or player wins (the survivor merely needs to avoid elimination).
• To win, a player must be lynched (the jester).

Election variants

Nominees for lynching may be allowed to make a speech in their own defense. Usually, each player must vote, can only vote once and cannot vote for themselves. But some variants have a more complicated process of selecting players to be executed. Davidoff's original 'Mafia' allowed multiple day-time executions (per day), each needing only a plurality to action.

Voting variants abound, but any lynching usually requires an absolute majority of the electorate, or votes cast. So, the voting is usually not by secret ballot for multiple candidates, with the highest vote count eliminated; it is more usual for the voting to be openly resolved either by:

• A nomination or series of elections structured to ultimately offer a choice between two candidates, or
• An option to lynch (or not lynch) one suspect (with a new suspect produced if the last one survives the vote).

Tied votes

Deadlocked elections can be resolved by lot, or by killing the player with the scapegoat special role.

The special case of one mafioso and one innocent remaining can be decided randomly, or be ruled a Mafia win (this is more usual in live play).

Another form, tie-breaking, can be had with a seance of the person who was last killed by the mafia, since night has not yet fallen and they have not yet seen the mafia during the night phase.

Optional lynch variant

The Innocents can choose not to kill anybody during the day. Although commonly unsure of Mafia identities, the Innocents are more likely to randomly kill a mafioso than are the Mafia (at night). Therefore, not lynching anyone (even at random) will typically favor the Mafia.

However, when the number of survivors is even, No Kill may help the Innocents; for example, when three Innocents and one mafioso remain, No kill gives a 1/3 chance of killing the mafioso the next day, rather than a 1/4 chance today (assuming random lynching). Lynching an innocent either day gives a Mafia win.

Timed days

A public timer is set to a pre-determined length at the beginning of each day. If the players lynch someone, then the day ends immediately. If time runs out, the day is over and there is no lynching, or the person with the most votes is lynched.

Mafia killing methods

Some variants require all Mafia members to choose the same victim independently for a kill to succeed. This can be achieved either by waking the Mafia members up separately, or by having them write their kills. Under this variant, Innocent players write the word 'honest' on a piece of paper; Mafia members write the name of a player for elimination. If all the mafia notes have the same name on them, that player is considered killed by the Mafia. In some online versions of the game, a particular player (the Godfather or a designated mafioso) must send in the kill. Another variant requires the night-time vote to be secret and unanimous, but allows multiple players to be added to the execution queue to ensure unanimity.

Random narrator

To eliminate the inconvenience of being killed first, this variant has the Innocent killed on the first night become the Narrator. The Mafia must inform this victim of their death without revealing themselves. The writing variant works best.

Multiple families

Multiple, independent groups of mafia or werewolves act and win independently, giving faster game-play and the potential for cross-fire between the factions.

Imprisonment

This allows players to be sent to prison as an alternative to execution. They can either be sent there by vote or at the discretion of an optional character. Imprisoned players move to a separate room, possibly with a separate narrator. Murders can happen in prison and certain roles or events can liberate players.

A similar variant is Kidnapping, which allows for a Kidnapper character to remove individuals from the game temporarily. If the kidnapper is killed (or, in some cases, investigated by an Investigative role), the kidnapped return. While kidnapped, players are inactive, and cannot watch night-time events.

Plague

A random player dies of plague each morning. A player who had targeted the plagued player the previous night may be infected.

Punishment

This variant is generally used as a drinking or risk based game. When a person is killed in the game they are made to take a punishment. In drinking circles this may be a shot of Gin or Vodka.

Lives

This variant requires the Narrator to keep track of the players' lives on a piece of paper, because every player has two or more lives. This extends the game when there are too few players for the standard rules. Kills (in the night & day phases) reduce these lives, until a player reaches zero lives and is eliminated. Mafia 'kills' which reduce lives are usually not announced to the innocents.

Attributes

In this variant, players are given two cards: the first contains their role, the second an attribute. Attributes were originally derived from roles that could apply to both Mafia and Innocent alignments such as Bulletproof (cannot be killed at night), Mayor (has two votes in the lynch), and Siamese Twins (more commonly known as Siblings or Lovers).

Ultimate Werewolf

The day time rounds remain the same as players sit around a table or in a circle in the candlelit base. The night time rounds are played roaming around the house in complete darkness. Innocents are killed by the werewolf tapping the victim on the shoulder in the dark. The victim must wait fifteen seconds until screaming in order to allow the werewolf to get away. Once an innocent is killed by the werewolf, everyone re-assembles in the base for the day time round. This variant of the game includes the Little Girl character who is allowed to collect a flash light from a prearranged place (e.g. at the bottom of the stairs) at the beginning of each night time round. Innocents who have been killed in the game become zombies and roam around in the dark (after a 30 second advantage on the innocents) in each night time round. Lovers need to find each other in the dark and protect each other from the werewolf.

Quantum Werewolf

This variant was developed by Steven Irrgang and used for a puzzle in the 2008 CISRA Puzzle Competition. He later published more formal rules so that it could be a fully playable variant. The difference from a standard game of Mafia is that players are not initially assigned roles, but rather on each day are given the probabilities describing the game's current quantum state. Each player with a non-zero probability of being a seer or a werewolf performs the appropriate night actions (which may not be effective if it is later determined that the player did not have that role). When a player is killed, the wave function collapses and the players are given updated probabilities.

Train Mafia

Traditional Mafia re-envisioned and heavily modified by the Copenhagen Game Collective to be played in a subway metro. In this variation, players who are 'lynched' are kicked off the train (at the next stop), and must wait in shame for the following train – a kind of 'afterlife' train – to join a second, interwoven game.

Invisible City: Rebels vs. Spies

This variant was developed for location-based mobile gaming using mobile devices. It was designed and developed for Android devices in order to be played in a city center. Because of this, the rules were modified in order to accommodate for the fact that players cannot observe each other in an open space. A second goal was to avoid eliminated players, because they can no longer observe the rest of the game. The two factions of the game are the Rebels, the majority, and the Spies, the informed minority. The rule-set avoids expulsions using scoring for each round. During a round each player has to carry out an individual mission. Some of the missions are critical and if one of those fails, the round goes to the Spies, but the players do not know whether their current mission is critical or not.

Game experience and strategy

Mathematical study

Mafia is a complicated game to model, so most analysis of optimal play has assumed both: (a) that there are only townsfolk and mafiosos, and (b) that the townsfolk never have a probability of identifying the Mafia that is better than chance. Early treatment of the game concentrated on simulation, while more recent studies have tried to derive closed-form equilibrium solutions for perfect play.

In 2006, the computer scientists Braverman, Etesami and Mossel proved that without detectives and with perfect players the randomized strategy is optimal for both citizens and mafia. They showed that when there are a large number of players to give both groups similar probability of winning, the initial number of mafiosi m need to be proportional to the square root of the total number of players P, that is ${\textstyle m\propto {\sqrt {P}}}$. With a simulation, they confirmed that 50 mafiosi would have almost a 50% chance to win among 10,000. The Mafia's chance of victory is

$W(m,P)\approx {\frac {m}{\sqrt {P}}},$

which is a good approximation when the right hand side is below 40%. If any detectives are added to the game, Braverman et al. proved that the number of mafiosi must remain at a fixed proportion of the total number of players for their chance of winning to remain constant.

In 2008, Erlin Yao derived specific analytical bounds for the mafia's win probability when there are no detectives.

In a paper from 2010, exact formula for the probability that the mafia wins was found. Moreover, it was shown that the parity of the initial number of players plays an important role. In particular, when the number of mafiosi is fixed and an odd player is added to the game (and ties are resolved by coin flips), the mafia-winning chance do not drop but rise by a factor of approx. ${\sqrt {\pi /2}}$ (equality in the limit of the infinite number of players).

Results in live play

In live (or videoconference) real-time play, the innocents typically win more often than game theory suggests. Several reasons for this have been advanced:

• The physiological stress of sustained lying degrades the initial ability of mafiosi to deceive the innocents, much more than a model of perfect play would predict, especially if the innocents can get the town emotionally involved in the game's outcome:

If you're trying to feign shock or anger, it's much harder to do over a long period. People accused of something they're trying to hide will start out feigning outrage -- 'How dare you ask me that?' But that will start to change to objection rather than shock, as it's psychologically very difficult to mimic emotion.

— Dr Simon Moore, Wired UK

• The information revealed by the mafiosi voting patterns tells against them later in the game. One of the game's fans Max Ventilla, has said that "If the villagers are allowed to keep a pencil and paper, they always win."
• As players get more experienced their strategic sophistication and ability to spot and use deception increases. They will typically get better at the skills needed for playing innocents faster, being villagers more often than mafiosi.

• The Metagame aspect: Dimma Davidoff has said, Past connections will always lose to future collaborations. When playing several Mafia games with the same people, it's more helpful to be known for honesty than for deceit. Davidoff considers that so important that he thinks the advantages of playing the mafioso role honestly outweigh the disadvantages.

But, the Mafia can win in live play; their best chance of winning occurs when mafioso bond with their innocent neighbours and convince those neighbours to value that bond over dispassionate analysis. The game designers Salen and Zimmerman have written that the deep emergent social game play in Mafia (combined with the fear of elimination) create ideal conditions for this.

See also

• Assassin (game)
• The Resistance (party game)
• Bang!
• Wink murder

External links

• The original Mafia ruleset
• Hungarian Mensa Society - first Mafia page on the net
• Werewolf at BoardGameGeek
• How to play mafia: A wiki how-to article
• Mafiascum Mafia Wiki - explanation on terminology, strategy & roles of mafia play, in particular forum mafia