This is a thread for me to lay out some actual 'rules' I use... for consistancy if nothing else, in playing in Haven. So far using Mongoose RuneQuest primarily.

Things you will see here:
Character creation notes, tying cultures to races to regions.
Cults: Any cult that makes an appearance in game should have rules for it, even if the players fail to use them. Thus, they will appear here as well. This is VERY IMPORTANT, and I've been seriously neglecting it.
Unique things: Artifacts and the like.
Fancy things: Metals available.
House Rules; Changes to the Rules as Written for MRQ, often adapting things from other 'settings' into Haven.  A bad example would be adapting Gloranthan Cults, slightly less bad: Hero Questing.


So, to start off lets detail some of the things I've done:

Rather than using RQ racial dice distribution, I've settled for providing a +2 to attributes for most races.  Orcs and Heshite Lizards get the bonus to Siz, Jungle Lizards and Dwarves get it to Con, Elves get it to Dex. Humans can pick, but no one can boost POW, leaving an offical hard cap of 18 to POW in my game.  No other races have come up.  Note that this does create slightly more powerful characters, though in Runequest they are still fragile.

Lizardmen from the Jungles (Amal and Avestite certainly) are Primatives and have access to Shamanism.  Hesh Lizardmen (a different breed entirely) are Nomads, but exchange a Ride bonus for Athletics.  All Lizard races get a 1 AP skin and d4 damage claws and teeth, and have a tail hit location.

The Elves of the Pepper Savannahs are Nomads, as are the Maxcai (humans). So to the Danu Tribes of the Sea of Grass far to the south. Savannah Elves 'worship' totemic Gods (Hunter, Sky, Falcon, etc...) many of whom are First Gods.  The Maxcai have a totemic form of worship but use Spirit Magic primarily.

MOST humans across Haven are 'barbarians', however. Peasants are more common in the Tenebrian regions, with Townsfolk being more common in the Nornsan area.  However, in general any built up city area will have 'townsfolk' as a dominant culture, and Nobles can be found among all Human and Dwarf cultures, with a number of Elven examples as well.

The 'Bearmen' of the Tundrid Plateau are Primatives, with each tribe having a totemic animal spirit-god. Essentially each tribe is its own Cult, and they do practice Shamanism as well.

Renbluve is essentially the sole place to find 'Civilized' cultural backgrounds.  The Tenebrian Empire does have a roughly equivilent level of sophistication and development but does not culturally support this background.

Dwarves are primarily 'Townsfolk' in background, in MRQ terms.  Dwarves use a fair amount of Divine Magic, with almost every Dwarf having at least one or two small 'emergency' divine spells to hand. However their primary 'Magic' is enchanting. Dwarves do have access to lots (and lots) of Earth Runes as a general rule, and more than a fair share of Metal and Fire runes as well, but those are most common among Nobles and warriors.  

Elves may have any cultural background. Some Danu tribes are primative, the Siti and elven communities on the Melitior Plains are Barbarians, the Illyacli are Townsfolk, along with Elves found in many human cities, and Noble Elves can be found alongside their brethen. Elves from Renbluve can be Civilized.

Dwarves are never Primatives or Nomads and only rarely barbarians. Dwarf Barbarians are usually exiles from a clanhold, or their decendents, living in a human community.  Even still, most Dwarves will prefer the teeming masses of a City, even if it isn't a Clanhold. As a point of technicality: Most Dwarven Warriors 'count' as Nobles. Dwarven leaders are responsible for the security of the Clanholds and the general martial nature of the work most Nobles are, not coincidentally, also warriors of some standing.   As a rule female Dwarves are also Nobles but only warriors in truly (Player?) exceptional cases, due to their low numbers and revered place in Dwarven society.   'Pure' spellcasters are frequently Females in Dwarven Society, as they are under less pressure to 'prove' their value with material value (crafting and fighting) to the Clan they can devote more energy to esoteric and 'nurturing' pursuits.   Dwarven players interested in 'theft' are encouraged to play Exiles, as Clanhold Dwarves have more communal senses of Property that make theft somewhat alien to them. Theft isn't even a recognized crime to most Clanholders, the big crimes being Hoarding and Dereliction of Duty, right after harming a woman (dwarven women only. They could care less about the gender of non-Dwarves. Male and Female humans are 'humans' not 'men and women' on the main.) or a child (any race).

On a note: I started using RQ2 (?) cultures and backgrounds and still want to expand the existing MRQ stuff using the greater depths available from RQ2 but I haven't really codified any of that.