Gacha game - Simple English Wikipedia, the free encyclopedia
A gacha game is a video game that has a mechanic of getting items or characters by spending in-game currency. The items or character players receive is random. The rewards are usually graded by rarity. Players can purchase in-game currency with real-world money.
Some gacha games have a pity system, where after a certain amount of draws without getting anything rare, the system guarantees the player a rare item.