Forumites who find themselves stumbling in here, but don't comprehend what this is about: please do read on.
Mafia and Werewolves are originally party card games (Mafia was invented as a psychological game at the University of Moscow in 1985), preferably played by a number of players as big as possible. In the most basic version, there is a group of innocents and a group of werewolves or mafiosi. Actually these games are totally equal with the sole difference the roles and other game elements may have different names. However, depending on the preferences of the host and the number of players, there may be a number of supplemental roles with special abilities and/or rules introduced that are intended to spice up the game. It's up to the real innocents to find out who amongst them are the intruders, out to kill the innocent ones. This game has a day and night cycle. Once a day the whole group votes for someone to be executed in the hope of discovering the victim is a wolf or mafioso. Each night the werewolves or mafiosi agree on an innocent person to kill. The morning after the group finds out who died that night.
In the discussion board version, you can investigate evidence to find out the identity of the villains. This medium also allows to create more elaborate settings. You will role-play a character you come up with yourself. Below in the rules section you can find a template.

During the reign of Ivar Vidfamne av Skaane and Hr?rek av Lejre, in the time of the year Jol (Yule) is drawing near, a local land owner of the region of Hordaland in Norvegr has collected a seemingly random bunch of niddingar (outlawed moral offenders) to inhabit an old heim (extended farmstead) of his behind the seven mountains. In exchange for keeping the farm up and running, they'll get a chance to reintegrate into society, to start with a society of their own. Why this man would give these individuals a second chance is as yet unknown, since they are considered legally dead by anyone else. Certain is they didn't have much of a choice, preferring this to an existence as wolves (vargar) in the barren wastes of Nordic winter.

When common sense is applied, many of the rules described below sound only reasonable. Yet, rules are a necessary evil wherever and whenever people choose to congregate and want to reach a goal with a sense of civility.

1. Play to win, even if the method I assigned you sounds somewhat unconventional at first. Whoever reaches his/her goal first, wins.

2. My aim is to keep the assigned roles a mystery. Don't openly mention your role, although the consequences will come to the fore in everyone's role-playing. These hints should prove enough. Try to look at it as a real life situation. You will be playing a role in a theoretically realistic situation after all. No one is ever going to say "Hey, I am an assassin!" (unless you have played too much Assassin's Creed), "I am the witchdoctor!" or "The matchmaker, that's me!"
Roles are assigned at random.
Of course everyone always can claim and attempt to prove they're "innocent" and have no part in this evil the group is presented with.

3. Play fair and keep up the fun for everyone. I can think of an endless array of hilarious ways in which I can god kill cheaters, although harm's been done already.

4. Unless specifically stated otherwise, all communication is kept within the threads, so no sneaky personal messaging off the board.

5. For the hypothetical instance there seems to be a balance issue (or just to keep the game fresh), I reserve the right to change rules or roles. Be assured, there will be no attempt to create an extra layer of anarchy.

6. Days last approximately 24 hrs. After about 21 hrs I'll post a statement the day is over and an execution (by vote of a majority within the group, see below rule 8) shall be performed.
The only exception shall be (real life) Mondays and Fridays. On these days there shall be no new thread, so this means the days started on Thursdays last till the next Saturdays. Likewise, you'll have time to debate and post from Sundays till the next Tuesdays. Questions still will be answered throughout the 48 hrs when possible though. As a host I apologize for my private schedule, which contains some more important matter that keeps me from updating more often.

7. I expect every character to contribute at least once every two game days. Anyone failing to make a contribution every 48 hrs (or possibly 72 hrs, see above rule 6) gets god killed. Anyone being inactive/lurking for three days in total suffers the same fate.

8. Every day the surviving group may want to vote for someone to be executed. An absolute majority of votes is needed to execute.
Unless stated otherwise trying to eliminate the opposing force (classically known as mafiosi or werewolves, for ease indicated as OpFor) is the main objective, while the OpFor may nominate someone to be lynched every night. However, expect some strange things to happen every now and then. Sometimes people will be converted to the other side rather then killed or due to various reasons a killing may fail. The end of the game is reached when an OpFor group outnumbers the innocents.

9. When you're dead: stay dead. Necroposting may be the worst thing one can do. Feel free to PM me if you want to continue sleuthing. I'll be more than happy to keep you posted.

10. There is a pattern to follow when posting. All "out of character" communication (including votes for execution, questions to the host about evidence and such) should look like this [bolded and in red]:

OOC: (question/remark/vote)

If it's a major remark I'll prefer you to direct it to me in a PM. In the case of votes it's easier to keep count this way.
Everything your character says must be typed as usual. Just put the name of your character on top of your contribution, bolded and underlined as in:

(character)

(role-playing and debating)

However don't overdo the role-playing and make sure your contributions are mostly useful to the investigations (although it may be stated otherwise to each individual).
Any non-verbal actions your character performs (like sitting down, standing up, walking back and forth, face palming...) must be put in italics as in:

(action)

Let's agree the host's colour to denote important info will be green.

11. Don't edit your posts (unless it's a silly typo or something similar). If you change your mind or want to revise your reflections in a previous post, just make a new post. If you need to edit a post, add at the bottom of the post exactly what you have corrected.

12. Evidence may or may not be clearly directed toward the OpFor. You can be set on a wrong trail, although I don't intend to do so on purpose. When answering your questions, sometimes it's more important to note what I don't say rather than what I put in my reply. If I don't reply to a question, it might indicate you're on to something and answering would give too much away.

13. Don't ever quote evidence you couldn't have gathered from debating. Unless you'd foster the ambition to be instantly god killed, so just don't. You're allowed to paraphrase others' statements.

14. A very important part of signing up is sending in a character profile to me. You'll only be definitely signed up after you've done so. You'll get to see the other ones' profiles during the game. I'll compile them. It should contain this info and look like the template in the character creation section below.

Remember your character profile may be used against you as evidence can be recognized as typifying for your character. Therefore it's important you provide the required quantity of traits and so forth.

Something that's of the uttermost importance to me as a host, is the fact the profile you create is the person you are going to be for the duration of this game. He/she is your voice and should effect everything you do or say. Don't look at it as a dry, static set of descriptions. Try to breathe the same air as he/she does. This is the board of a company that creates role-playing games, so give that aspect your best shot.

When I manage to write satisfying write-ups, I hope you will feel encouraged to do your best at role-playing and sleuthing. This in turn may keep me intrigued by your characters and incite me even more to do the best job I can as a host (not that I'm anyhow planning to do a sloppy job though). This is a fruitful way of interaction.

15. All further information not shared above will be provided in unique PMs at the beginning of the game.
Feel free to ask any questions by PM (or in the sign-up thread while it's active) if anything still isn't clear though.

Name: pick a Norse name http://www.vikinganswerlady.com/ONNames.shtml, http://www.behindthename.com/nmc/sca-anci.php, http://www.ellipsis.cx/~liana/names/norse/sg-viking.html, or feel free to ask me for help, patronym and/or byname optional
Age: preferably between 13-45 since people didn't age well
Gender: M/F
Build: slim, muscular, average, athletic, big-boned... Certain flaws or effects of previous illnesses or other afflictions?
Height: if you're used to the imperial system, please include the metric equivalent. Here's a http://www.tech-faq.com/convert-inches-to-centimeters.html. I http://www.hurstwic.org/history/articles/daily_living/text/health_and_medicine.htm: "The average height of men in Norway in the Viking era, based on skeletal measurements, was 176cm (5ft 9in), with a range from 170-181cm (5ft 7in to 5ft 11in), which was taller than other Europeans during this time. The average height of women was 160cm (5ft 3in), with a range from 149-164cm (4ft 11in to 5ft 5in)."
Appearance: clothes, hair length (must be at least shoulder length [even obligatory by law for women], unless he's a slave or has encountered serious issues) and colour (bleaching was fashionable), eye colour, beard (preferably at least a goatee, unless it fits the character to be mocked because he can't grow one), tattoos... I'm in love with this epoch so I will correct characters wielding two handed claymores and horned helmets or anything other too Conan
Occupation: farmer is the best option, others are (only part time or in summer) blacksmith, trader, woodworker, fisherman...
Personality: preferably 3-5 positive and as many negative traits
Beliefs: does your character honour the ?ser, rather the Vaner or is there a different relationship? How does he/she look at the world, life, him-/herself?
Life goal: where does your character want to be within the next years?
History: the life of your character before he/she ended up in this place, will be rather short because of the setting. Add anything else that doesn't fit elsewhere above.
Offence: what is yours? (list below)

Reliable sources for character creation:
http://www.hurstwic.org/index.html
http://www.vikinganswerlady.com/
https://thevikingworld.pbworks.com/w/page/3909821/FrontPage

[sarcasm]Congratulations![/sarcasm] You are nidding because of:

-ergi: effeminacy, unmanliness, cowardice, refusing holmgang (duel), refusing blodhemn (blood vengeance) in certain instances, refusing other types of retribution to restore one's and one's family's honour, practing seid (magic, reserved for female shamans called volver, morally prohibited for men), sometimes linked to physical disability, other signs of weakness, (especially when being the passive part of) same six activities...
-sixual perversion, moral degeneration
-madness
-murder (when killing in secret f.ex. by poison, while other ways of killing can be legitimate)
-theft (may involve seid, done at night)
-(other) nightly illicit operations (f.ex. nightly arson)
-dishonouring the gods
-dishonouring the family /spouse's family
-defilement of graves
-breaking oaths, treason
-breaking peace during Thing, festivities, on holy grounds (where bearing arms is prohibited)
-being a berserker: especially when berserking tactics are used against others to acquire women and property

-for women: manly acts/behaviour, dressing up as a man, carrying weapons, sixual debauchery/lecherousness, abuse of seid against her kin, dishonouring the family/husband's family

...

Q. What do I need [to do] to play?

A. Make up a character, once the game begins reserve five to ten minutes a day to read, debate, sleuth and/or vote and you're good!

Q. Damn it! I'd like to participate, but I have no idea how to make up a character! Now what?

A. Ask me for help and with a few directions you'll have one that fits in nicely.

Q. Win conditions?

A. OpFor outnumber innocents as in 1<0, 2<1 and so forth.
Innocents successfully discover and lynch all OpFor.
Other goals based on personal role description.

Q. Double executions?

A. Since an absolute majority of votes is needed, double executions will be impossible. As in 11/20 or 6/10 votes to lynch doesn't leave room for another one.

Q. Aren't you way too strict on accuracy?

A. You're serious about the game, so am I. You've let me understand well enough you wouldn't like it if I took this too lightly. Well, there you have it.

Q. How do you mean, beliefs?

A. Without getting philosophical: if you'd read the character creation section well enough you'd have known it's about disposition toward the ?ser and/or Vaner among other things. What does your character think life is about? How does he/she feel about the world around him/her? There are libraries full of books on these things so I'm sure that question is not impossible to answer.

Q. I don't see possessions in the character creation, what about them? They must be in.

A. That was a last minute removal for the reason you'll start as outcasts who have barely survived during the last couple of months/weeks in the woods without any access to agriculture or trade. Your possessions have been declared forfeit since you're legally dead and hence you lost everything. I'm sure you'd still have left a wagon full of trinkets by then. /sarcasm That it's not in character creation doesn't mean there won't be any items in the game. You'll arrive at a wealthy farm for that matter, so you can expect there will be some objects in there.

Q. Is this game about Vikings?

A. The Swedish king Ivar died circa 700 CE at the latest or that's what a number of researchers agree on. The Viking Age officially started 793 CE with the raid of Lindisfarne. So the answer is no. [ELABORATION] However, this is a period wherein things are going well for especially Sweden (Vendel Age) and in fact archaeological data from this era seems to be richer than the age where many left and hoped for the best (Viking Age). By the way, these days a good bunch of people in the academic milieu would agree that Viking Age is just a very ugly word to describe the whole of the Scandinavian Late Iron Age. So I won't use it myself. Besides, in this game we're rather in what one'd call the Early to Middle - or even simply Germanic Iron Age to be more accurate. Technically speaking, most of Northern Europe had only a very short Medieval Age - some regions even didn't live through one.