Recently I have been observing a lot of gaming companies pushing contents in their games that to my understanding should meet the definition of gacha. Yet, for some reason those games manage to avoid all the restrictions a gacha game should have, in particular the requirement to disclose the drop rates of items that are randomly acquired thru loot boxes.
I am therefore wondering what the actual requirements for being classified as a gacha game are and how those companies manage to slip past the rules.
For sake of clarity let's compare two different games from the same developer, I won't name them.
First, there is an actual gacha game. You play by using characters cards that you get from a random pool by spending a special currency. That currency can be got both in a limited amount by playing the game or by spending real world money. This game discloses drop rates. Second is a mini-figure battle game added on top of an already existing fighting game. You still get figures from a random machine, you still pay with a premium currency that is both available by playing the game (at an horrible rate requiring hours to collect) or "booster dlc" that you can buy repeatedly. In this case, the rates are NOT disclosed, so apparently this is not legally recognized as a gacha feature despite the clear intent is to profit on whale players who buy thousand $ worth of "boosters".
The question is therefore simple: what are the actual requirements for a videogame to be considered a gacha game and have to respect the rules gacha games have? Since the rules are too sparse in Europe, I will be fine with an answer that only discuss Japan, optionally USA if you like.