Patreon is a way of supporting people working in the creative arts. There are essentially two models: either you pay when the creative posts new content (such as a webcomic artist, vlogger or podcaster) or you can pay monthly to support the development of continuous new material.
My Patreon takes the latter form. You pay monthly (from $2-$5). This helps me to cover the costs of the subscriptions to the various pieces of software I use to format and design the books, to help pay for the miniatures and terrain and to contribute a little bit towards the artwork I've commissioned for the rulebook. Patrons receive various forms of reward, depending on the level at which they back the project.
For the purposes of this game, you get access to the beta rules from the $2 upwards. Once you back, you're committed for the first month, but you can cancel at any time after that. So, basically, you can get the latest version of the rules for $2 and walk away. The onus is on me to make the experience of supporting me longer term more engaging and worthwhile.
Most of my patrons are just happy to help me put the game into production, but I like to send free stuff to people whenever I have the leeway (and do monthly raffles for free stuff, too, including painted minis and - as Marc will tell you - I'm not too shabby with the ol' brush).
The rules themselves should be published through WGV on 29th March. If everything goes to plan, you'll be able to get the PDF (for £15) or a POD print copy (for £20) or a package of the two for £30. If things don't go quite so well to plan, you'll be able to get a beta of the PDF for £12, but will automatically be able to download the finished PDF when it's ready for no more money, which really should be by the end of April.
Alternatively you can back the Patreon for $2. The final version of the beta rules are about to be released, so your timing is good.
"But wait," I hear you cry, "if I can get the rules from the Patreon for $2 and the rules are basically finished, what's the Patreon for after this? Will it stop?"
No, because, as everyone knows, the rules are only the first product. For a start, we will have the first campaign book to come. That will be followed by several supplements. And these will all be exclusively released through Patreon first, and only later released for public consumption. Also, once ZD is published, I'll be expanding the Patreon to cover additional material for Horizon Wars, and hopefully developing a couple of other (unrelated) games that I've had waiting for more attention for a while.