Gacha Games are often free to play mobile games with various time-limited collectible items which can be obtained with in-game, or real-world currency. The items usually range in rarity from common to super or even ultra-rare.
The word Gacha actually is slang for Gachapon, which is a sound made by toy capsule machines in Japan. Unlike the toy capsule machines in the USA, the ones in Japan are full of actually really nice items. Many of the items have tie-ins to famous anime or video games and are much higher quality in terms of material and construction when compared to capsule toys in the United States. Also, like the mobile games, the contents in Gacha Machines are rotated frequently to feature seasonal items or special collaborations, making the race to collect your favorites even more exhilarating.