The mechanics and another indulgence combined with them have used up over a page and a half for me!
I find dialogue hugely expensive on word count and presumably space as well so have mostly avoided it this time but with some ideas that is not an option. I would love to try the challenge of doing a 4 page gamebook with lots of dialogue in though. I would want dice mechanics as well though.
In the home menu in microsoft word there is a submenu for line and paragraph spacing. It includes the option of removing the space above a paragraph or below it or both. I suspect that will cut down on lots of wasted space for you.
Simon's comment was that we cannot go below font size 10 simply because it would become hard to read otherwise. He, himself looks to have used tricks to reduce the spacing in the adventures of his in issue 1 of the Gamebook Zine.
Yes, there is an absolutely huge amount of space going to waste between the numbered sections.
I reckon you can seriously get away with reducing the space between them. I've used both the "remove space after paragraph" function" and I have also formatted the hard returns between the numbered sections by reducing the "font size" of the hard returns there.
Doing this has not in the slightest had any negative impact on how clear the adventure is to read and I am on 2,372 words and still have wiggle room as a result. My gaps between the numbered sections are now 7mm wide, compared to the full 1cm they were previously!
I have actually been fairly indulgent with my spacing in some places. Where I instruct the player to make a stat roll, I have the which section to turn to according to the result they rolled, after a small space, which I could have deleted. It just looks nicer. If I have a big idea which requires a lot more room, I will delete those spaces if I feel it is worth it.
I full agree that knowing how to use formatting to make the best use of the space is a huge advantage.
Best of luck with it all and I hope you are having fun.