Apple's App Store Review Guidelines is the law of the land of the App Store. Inside this document you'll find everything you can and can't do inside Apple's walled garden, and over the years Apple has modified it to stay on top of new trends on the App Store. If something problematic is popping up, it usually doesn't take them too long to add an official rule to the guidelines so everyone is on the same page. Well, it seems the recent "loot box" drama of Star Wars: Battlefront II which set the internet on fire might have caused Apple to institute an official policy before they face a similar PR disaster of their own.
Per section 3.1.1 on in-app purchases, Apple has added the following bullet point:
Apps offering ?loot boxes? or other mechanisms that provide randomized virtual items for purchase must disclose the odds of receiving each type of item to customers prior to purchase. Basically, the App Store now operates on the same level of some Asian countries which have laws on the books about loot box (or gacha) mechanics. If you're buying something random, you need to know your chances of getting things. Historically, Apple's policies have favored consumers, and forcing developers to show that the cool hat you really want out of that loot crate only has a 0.001% chance of being there when you open it is pretty consumer friendly.
It'll be interesting to see what if any impact this has on the popularity of gacha mechanics in mobile games. Scratch off lottery tickets...