Something that I've noticed in Candela Obscura & other recent games is the decision to NOT include character sheets in the book, and instead just link you to the web-site.
THIS IS A TERRIBLE IDEA.
I have games that are over 30yrs old in my bookshelf. Do you really think your web site is going to still be around in that much time? Many of my books link to sites that no longer exist, or downloads that no longer exist.
