“ You come upon a ruined building in the back section of a city park (or other out of the way area of the city). The ruins are fairly overgrown. All that is really standing is a doorway and its frame. If you pass through the opened door, you travel to a different world. If the door closes, there may not be a doorway back to get you back.”
“ The World is actually a number of continents surrounded by oceans, which are in turn surrounded by mountains. The oceans rush off the edge of the plateau on which the World sits into the Outside...”
“ Ten powerful magic rings created by an Archmage have scattered to ten random people (suggest only one is PC). This happened when he died in battle. Whoever gets all ten rings inherites all the power the Archmage invested to them over his 200 year life.”