an RPG using procedural generation not for building random worlds but for making detailed static worlds the way it'd be built is this... an artist starts up an editor tool that connects to a central server. the server sends down the current map data and all that on the fly -- this is so multiple users can work together on world building the editor has a preview window, which is an embedded version of the game renderer, switchable between walk and fly modes, and edit and view modes when in edit mode, you can add/delete/resize areas, edit heightmaps for areas, or go into paint or delete mode in paint mode, you can select either a given object (a tree, a path, stones, etc) or a template (e.g. a forest which places trees, twigs, and stones randomly, a swamp, etc) then you simply paint over the landscape. the editor randomly creates stones, trees, etc of different sizes and textures, then places them in those areas if you're painting a path, it will automatically remove things like trees delete mode is painting in reverse :P this allows you to create the world at a high level overview, then the artist can go in and do custom placement and such that way you end up with a highly detailed and very diverse world without all the work, and without a massive team of artists and with the multi-user editor, it could actually make Free games viable -- getting a massive team of artists together is hard, getting a lot of people to sit in a world builder like that is much easier :) non-destructive editing? maybe that's not really the same thing have a forest, draw a path through it, let me fiddle the path around like a vector editor rather than having to redraw path and cover the old one with forest again exactly. this type of placement makes that easy and it makes the data tiny. your world files will be a few megs because there are no meshes in it. all of your objects are generated on the fly, you just lock the parameters :)