I'm not sure how different it would be to pitch an RPG (Role Playing Game) manual to a publisher compared to pitching a novel, but I don't have any experience so it's all the same for me.
Let's say I have 100% of the writing completed (unrevised, unedited). How much of what I've written should I bring to the publisher to pitch my idea? I would be tempted to bring the whole thing and leave it to them, but what guarantees do I have that they won't just steal the idea and publish it on their own?
Which brings us to the second (related) question: what do I need from a legal standpoint to safeguard my work before involving a publisher in the United Kingdom?