Sounds like you need to work on the other aspects of your world first. I find that be really getting into the who what why and whens of it all, you can find ways of running all manner of campaigns with whatever style, themes and flavour you wish.
[sblock]Have you mapped out the cosmology? Are there gods? Where do people go, if anywhere, when they die? History? If you have dungeons or ruins, who built them? In the case of ruins, what ruined them? Magical items? Do you have any? Who makes/made them? Where are they, the items and the makers, now? Are there other planes of existence? How do, if at all, people interact with them? What lives there and can they/do they visit?
With our current world, the third in our campaign, I started with a theme: 1001 Nights meets Ravenloft. Then I added an interesting seat of power for the local big cheese, added another smaller trading community, and then scattered some adventuring sites and terrain. Questions to how the ruler kept power were answered next, followed by threats and ambitions. Then it's other forces that threaten and so on.
While working on that, questions of magic would pop up so I'd make notes on a few ideas. As more pieces came together, magic and its role naturally found its place within the continuity of the world. In this case, drawing inspiration from Ravenlot's mists, magic is kept 'quiet' by The Sands, a mystical aspect that threatens spell casters who use magic while in the desert (which is 80% of the campaign map at this time.) How it threatens is left to the DM, but its typically a Sam Raimi style vibe, where magic can produce unwanted (and often horrible) side effects, typically in the form of the attention of monsters and dark forces.
With the previous world we have a totalitarian academic institution that controls magical innovation and research, which is referred to as SCIENCE. Long story short, excessive peer rivalry and an ingrained fear that magic (i.e that which is not SCIENCE and cannot be trusted) causes mental instability (which buys a ticket to a nightmarish Victorian-style mental hospital) means that 1st through to 3rd level SCIENCE is more widely accessible, at the cost of continued scrutiny, paperwork and faculty obligations. Beyond 3rd is 'experimental' and thus dangerous, obviously the work of con-men, charlatans and the mentally deviant. The in-game result is that magical ability comes with a lot of role play baggage that is intrinsic to the campaign setting, has worked very well, with all our players of magic user embracing the fun/spirit crushing bureaucracy. It also neatly avoids the problem of low level magic-marts and magical services because it is not acceptable for practitioners of SCIENCE to stoop so low as to meddle with the affair of the common people. Those that do are obviously deviants and showing signs of mental instability - cue the horrible Victorian mental health treatments.
So aye, who what why and when. Much easier to fill in the gaps when you have enough things to actually make gaps. [/sblock]
1) the cosmology is fairly basic. The Chaos has leaked through a lot of the planes, so there are many fewer than default. All of the elemental planes are intact, since they are chaotic already. The Fey wild has been mostly cut off from the world, making it difficult to access. There is a celestial place, where the gods meet, though each god has their own demi-plane. There is the full nine hells, but instead of being different planes they are all a massive tower. All of these planes are accessible through portals, though the Fey portals are rare and unreliable.
2) there is a plane of death, though I have not fleshed it out completely. I had a thread a while back talking about it, basically describing it as a massive endless blizzard. Eventually an old man (death) comes around to offer you the afterlife you have earned, after you have been walking for a millennia or two. Off course, that is much less time in the real world, since they are on different time speeds. At a rough guess, I would say 1 second=1-2 millenia.
3) history is light, but I should get around to actually writing out the New history.
4) the dungeons and ruins are either currently inhabited by the original builders, or were built before the Chaos resurgence. To lay out the basic idea,
Primordial built the world, forging it out of the elements, then Chaos pulled in to retake the space. The Primordials, and a host of other gods they called on, fought the Chaos. All of this collective divine energy made the Material plane overflow with positive power, marking a great age of expansion. Then the gods started dying, one by one, and the world started to look worse. Without going through all the details, only seven gods survived the Chaos War, leaving divine power in short supply.
This all resulted in a massive expansion of civilization, before a massive collapse. This left all sorts of old places and relics that serve as ruins and dungeons.
5) I think there are magic items, but I am thinking they will be few. Interesting, but few. They will have been constructed by people looking for utility during the Great Expansion, or maybe a few newer ones made by people wanting a way to survive the chaos. Lastly, there will be Planar Shards, flexible pieces of the raw energy from a given Plane. These shards have specific properties, and will adjust themselves to the preferred form of the first person to come in contact with them. If they are ever taken to their Plane of origin however, they will return to the Plane.
6) I answered this one a little above, but here is a more in depth version. The Elemental planes are accessed the usual way, through portals lying in their element. The Hells are accessible through deep, deep, deep tunnels, where the earth starts to become hot. The celestial plane is only accessible by invitation, as it is essentially a fortress against the Chaos. The Fey is accessed through usual fey means. A fairy circle, a hole leading into a hill, or an open knot in a tree. However, the number of these portals that can be found dwindle every year, and will eventually be gone entirely if no one makes a push against the chaos that is slowly claiming the Fey Wild. All of these planes have visitors sometimes arrive from them. The Hells, elemental planes, and Fey are the most common. The Hells come because they are either taking advantage of the chaos, or because they actually have an interest in keeping order around since it keeps them in their given seat of power. The Elemental are mostly accidental, just happening to walk/swim/fly through a portal. The Fey come asking for help, hoping they will find someone capable of pushing back against the Chaos that is chewing through their realm. It is not unusual for Feylocks, or Oath of Ancient Paladins to be called on by the higher powers in the Fey Wild, once they have shown competence in adventuring.
Thanks for the questions, and sorry for the Wall of Text.
