This month's Humble Monthly is offering an early unlock of H1Z1 to those who subscribe. That'll cost you $12 / £10 at the moment if you fancy it. H1Z1 is currently available from Steam for £14.99 / $19.99, so even if it's the only game you want out of this Humble batch, you're in a good place.
If you've been reading regularly, odds are very good that you'll know what the Humble Monthly is by now. If not, the short answer is that it's a monthly subscription that'll get you a big ol' batch of game keys each month. If you happened to have been a subscriber around this time last month, you'll now have access to ten games including Shadow Tactics: Blades of the Shogun, Quake Champions, Dead Rising 2, Elder Scrolls Online, Resident Evil 5 Gold Edition, and a bunch of others.
Subscribing now gets you H1Z1 right away, with more games to be added for November's haul later in the month.
We recently revisited H1Z1 in Update Night, our column where we ask whether an in-development game has been improved by its updates.