Loot boxes are not gambling in the legal sense unless you could win actual legal tender from them, and that’s all there is to it.
1. I live in Texas, where gambling is illegal by state law, with the exception of a state-run lottery system. I live nearish the north border, and it is common here for people to travel to Oklahoma casinos to gamble, where it is legal to do so there.
2. Texas does, however, allow Chuck E. Cheese’s to exist, or the “insert coin, get plastic toy” gumball-machine style devices that children can blow their entire allowance on if left unchecked, because you don’t receive legal tender from them. Even if you are inserting tokens into a device that spits out a random number of tickets based on no skill whatsoever, or even if you are playing a completely rigged claw machine whose claw-strength is random to offer an illusion of skill, those are legal under anti-gambling states because your potential prize is not actual money.
3. Using your favorite dictionary entry to try to officiate language as if to “prove” that loot boxes are actually gambling, is a definitively false understanding of the existence of dictionaries.
4. The issue is not that you’re risking actual money for something, but that you’re risking actual money for a possible prize of actual money. If all you can win is something not-money, even if that not-money prize can be used like money, it isn’t gambling unless the prize is actual legal tender.
5. If the loot box you bought with actual dollars could win you actual dollars, then it is definitively gambling in the legal sense. If the loot box you bought could not even possibly win you actual dollars, even if there is any level of “risk” of not getting the non-money prize you’re hoping for, it is is not gambling in the legal sense, period.
6. The ESRB is not a legal-regulatory body. It is a review system like Siskel & Ebert or the MPAA, who have no authoritarian control over whether children are legally permitted to view films. They can issue ratings like S&E/MPAA about recommendations, but their ratings are not law, and a retailer cannot be taken to court for failure to restrict a child from buying an ESRB-rated game, because the ESRB does not institute legally-binding ratings.
7. Considering this to be gambling would not only undermine Chuck E. Cheese’s and claw machines, but also basically any kind of “blind” unreturnable product packaging such as baseball, Yu-Gi-Oh/Pokemon, Magic: The Gathering, and other collectible cards that have a randomized set of cards that propose you collect the full set of or could have more valuable kinds within and could be resold for profit. For that matter, cereal boxes that have a collect-all-three plastic toy gimmick, or Happy Meals. Perhaps those who shoot down loot boxes as gambling may have even gotten their legal degrees in the form of a lick-and-stick tattoo from a random Cracker Jack box..