Cave Goblins should be a civ. Man but I loved the quest line... Check out their actual name though, was something with a D.

Its written dorgeshuun

Gnomes, Orges (Or Bandos), White Knights (or Saradomin?), Demons/Zamorak, Black Knights, Cave goblins (as mentioned above), Sea slugs (or whatever they were called), Elves (Seren), Wizards as their own factions?

Play as Varrock, Falador, and Lumbridge.

How about the actual countries of Runescape, Misthalin (capital: Varrock), Asgarnia (capital: Falador), Kandarin (capital: Ardougne), Morytania (capital: Meyerditch), Fremmenik Isles (capital: Rellekka), Kharid Desert (capital: Al-Kharid), Tirrawn (capital: Priffindas) and Karamja (capital: Shilo Village).

Originally posted by Mads the Great:

How about the actual countries of Runescape, Misthalin (capital: Varrock), Asgarnia (capital: Falador), Kandarin (capital: Ardougne), Morytania (capital: Meyerditch), Fremmenik Isles (capital: Rellekka), Kharid Desert (capital: Al-Kharid), Tirrawn (capital: Priffindas) and Karamja (capital: Shilo Village).

That.

Originally posted by Mads the Great:
How about the actual countries of Runescape, Misthalin (capital: Varrock), Asgarnia (capital: Falador), Kandarin (capital: Ardougne), Morytania (capital: Meyerditch), Fremmenik Isles (capital: Rellekka), Kharid Desert (capital: Al-Kharid), Tirrawn (capital: Priffindas) and Karamja (capital: Shilo Village).
Yes That.

Well technically, Al Kharid is independent from the rest of the Kharidian desert.

Maybe add Pollineveach and Nardah as city states?

I like the list, but there are two things wrong with it. First, there must be 2 more civs in order to make it a huge map. Second, I feel aradougne would have too much land (which could be fixed by adding the two other civs there) Other then that, the list is good.

Maybe Feldip Hills and Seer's Village + Catherby as the last two civs

Why not have the city states include the guilds?

Originally posted by Mads the Great:

How about the actual countries of Runescape, Misthalin (capital: Varrock), Asgarnia (capital: Falador), Kandarin (capital: Ardougne), Morytania (capital: Meyerditch), Fremmenik Isles (capital: Rellekka), Kharid Desert (capital: Al-Kharid), Tirrawn (capital: Priffindas) and Karamja (capital: Shilo Village).

This sounds like an awesome idea!!!!!

How about, just an idea for some unique things for the civs.
Varrock: Grand Exchange, replaces Palace, +50% gold.
Asgarnia: White Knight Castle, replaces castle, +25% construction when building melee units
Kandarin: Trade Centre, replaces market, trade routes can travel 50% further
Morytania: Vyrewatch, replaces pikemen, has 4 movement, and is a hovering unit
Fremmenik Isles: Long hall, replaces armoury, +30xp instead of +15
Kharid Desert: Camel farm, replaces caranvasary, does the usual, but also adds 25% to building mounted units
Tirrawn: Crystal range, replaces barracks, +25% to building range units
Karamja: Tribal spearman, replaces spearman, can move through terrain easily, and can chop forests, jungles and marshes.

Penguins, don't forget the penguins!
Don't forget the Monkeys either!
Here's a complete list of races for reference:
http://runescape.wikia.com/wiki/Category:Races

I would make tutorial island a civ
a posssible special could be all units get +15 xp (or more)