I\'m sorry for answering late in this thread but I encountered a bug in the forum preventing me from replying, and since monday evening my adsl connection is down (and my emergency rtc connection is overcrowded *sighs*).
Let me introduce you to Leander\'s awesome compass, available for only 200 trias:
http://leander256.free.fr/ps/compass.png
The framework is protected from the imponderables of an adventurer\'s life by a very solid glass. The metal parts are very light so gravity and friction don\'t cause many troubles to the mecanism.
The arrow shows you where is the center of the level, the blue part being attracted by the crystal (and the green one can be repulsed or just neutral, balancing the arrow). Plus the angle gives you an indication about how far from the centre you are (provided you know on which level you are). Maps could probably look like that (sorry for the crappy map):
http://leander256.free.fr/ps/map.png
That\'s the map of the town... The black dotted circles are delimiting zones with different vertical angles of the compass. So you get an idea of where you are, you just have to rotate the map until you find out your position.
Of course this method is not very precise, but remember that dropped in some unknown land with only a map and a compass (in real world), you won\'t be able to find your position easier.
Then we had a long discussion with Lynx_lupo, I\'ll try to sum up (sorry for the late posting Lynx_lupo, and feel free to correct me). May I precise that we don\'t want to create the world instead of the people officially in charge of it, we had to make some assumptions.
First there\'s this problem of the players getting involved in the game. If the players want a coordinates system \"out-of-the-box\", something they can use without even thinking about it, it will be better to keep the Earth coordinates, even if it means producing some artifact to integrate the \"N E S W\" coordinates in the world. On the other hand, if we assume that people will accept spending a few hours getting used to an \"innovative\" (let\'s say non-natural) way of locating themselves, we can keep the crystal as the center of the universe (and add a little something I\'ll describe later).
Second there\'s the problem of \"people vs character\" gameplay: Do we have to consider it\'s up to the player to be able to orientate himself, or does the game have to guide or mislead him depending on some of his character\'s skills? It\'s a very common problem when creating RPGs. In the first case, we create an inequality because somebody who wants to play a ranger will get lost in the forest (not very interesting), in the second case people with a good sense of orientation don\'t need to pick up the adequate skills, so they can take other ones, which also creates an inequality.
We still had a problem with the compass because a compass alone can\'t give you your coordinates, as you can see on my drawing, you can be everywhere on a circle that can be quite large. That\'s why I thought about adding something else to the compass, based upon a crystal\'s property that doesn\'t exist (yet?). As you can see on the pics, the crystal has 7 faces. Let\'s suppose it\'s put on some altar or anything holding it like that:
http://leander256.free.fr/ps/yliakum_map.jpgNow let\'s ALSO suppose (makes a lot) that each face can send waves at slightly different frequencies (I know some people already proposed things like that, I don\'t mean to steal anyone\'s idea). Every level is now divided in 7 sectors, and depending on your position in the world, you\'ll ba facing a different face of the crystal. Consider each face as some sort of speaker, a magical device will be able to detect the strongest signal, giving you an angle relative to some predefined origin. Something like that:
http://leander256.free.fr/ps/angle.pngThe blue line glows at the angle where you\'re supposed to be. We now have a complete polar coordinates system, which is different (maybe difficult), but also probably unique (and people here like to say that planeshift should be unique).
As a conclusion: I\'m sorry for crappy pics

and wait for your reactions, counter-proposals, etc... And thanks for reading till the end.
EDIT: I can\'t put pics straight into the post because in this case the bug occurs...