Writing the rule book is the last thing which needs to be completed. While most of the game components need to be produced well in advance in order to have any chance of being ready before Christmas, the rules leaflet is easy to print in the UK.
Having said that, getting it right is still one of the tricker aspects of the project. Whether a game works or not depends on how it is played. As each copy of the game doesn’t come with a mini version of me, writing down what to do is really the only sensible way.
I consider myself to be fairly good at explaining complex things in simple terms. I used to draft statutory instruments for Parliament. Fine, but it turns out that writing a rule book is a whole level of difficulty above that. There are the straightforward actions to cover – what a player can do, what’s not permitted. There are the cards drawn, and the consequences of drawing a red card (generally bad, in this game). And then there’s showing the board and cards in the instructions so that players can recognise which cards are which. All very well and good, expect that the instructions now appear to be twelve pages long.
It’s probably a good thing that this is the least urgent item.