Get started on wikipedia and gain some experience doing small edits and learning the ropes. Time enough for big ambitious edits later.
I guess I might still try to rewrite the Obsidian Chronicles articles, but that still might be too ambitious for me, because in their current state, they are going to need alot of work, and im not all that fluent on the wiki programming language and formatting syntax etc. etc.
Wikipedia articles can be copied and modified by anyone, but there is a catch: All modifications have to be made available under the same conditions, and credit has to be given to the original authors.
However, when editing Wikipedia, please only add content which you have created, or which you have been permitted to use under the terms of the licenses mentioned above. Otherwise, it will be removed.
