https://www.pcgamer.com/choose-rise-of-the-tomb-raider-or-sniper-elite-4-in-the-new-humble-monthly-bundle/

The Humble Monthly Bundle for September features a first-time-ever twist in the style of Let's Make a Deal. For $12 you can take home Sniper Elite 4, Tales of Berseria, and Staxel right now as the "early unlock" games for the month—or you can go for what's behind Door Number Two! Which in this case is not a live goat but Rise of the Tomb Raider, which subscribers can select in place of the other three games as an "alternate early unlock option."  

Aside from that, the September Humble Monthly works exactly the same as those that have come before it: You pay for the bundle, get the early unlock games right away, and the balance of the package (guaranteed to be worth a minimum of $100 retail value) at the end of the month. The August monthly package included The Surge, Sudden Strike 4, A Hat in Time, The Escapists 2, Conan Exiles, Kona, Forged Battalion, Pathologic Classic HD, and Woten. That's not bad for 12 bucks.