Gacha Game
Gacha games are video games that adapt and virtualize the "gacha" (capsule-toy vending machine) mechanic. In the monetization of video games, it is similar to loot boxes, in inducing players to spend money. Most of these games are free-to-play mobile games. In Gacha games, players spend virtual currency, which can be from a machine; however real money is usually eventually spent to obtain the virtual currency and opportunities to use it.
The gacha game model began to be widely used in the early 2010s, faring particularly well in Japan. Almost all of the highest-grossing mobile games in Japan use it, and it has become an integral part of Japanese mobile game culture. Outside Japan, the game type is also gaining popularity. Puzzle & Dragons, Dragon Collection, Granblue Fantasy, Girls' Frontline, Monster Strike, Fate/Grand Order, and Kingdom Hearts Union X. This type of game is increasingly being developed by Chinese and Korean companies, too; notable examples include Azur Lane (Chinese), MonsterCry Eternal (Korean), and League of Angels (Chinese).
Model
In these games, there are usually numerous characters, cards, or other items that players can obtain, and most of them are only obtainable via a "gacha" mechanism, which will allow players to "pull" or "spin" the gacha (analogous to a slot machine or roulette wheel) using a specific amount of in-game currency, which will then give player a randomized character, card, or other item. Sometimes, these gacha are limited, such that specific prizes can only be obtained within a specific event time-frame. Because some of the rewards have a lower chance to appear, typically players must spin the gacha many times before they get their desired outcome.
In many games, gacha are essential for players to make progress in the game. Players may be given free or discounted gachas, but have to pay to get more. These games may also feature different tiers of gacha pulls, which give different sets of rewards.
The model of gacha has been compared to that of collectible trading card games as well as to gambling.
Types
Complete gacha
"Complete gacha" (コンプリートガチャ?), also shortened as "kompu gacha" or "compu gacha" (コンプガチャ?), was a monetization model popular in Japanese mobile phone video games until 2012, when it was rendered illegal via legal opinion. Under complete gacha rules, players attempt to "complete" a set of common items in a particular loot pool in order to combine them into a rarer item. The first few items in a set can be rapidly acquired but as the number of missing items decreases it becomes increasingly unlikely that redeeming a loot box will complete the set. This is particularly true if there are a large number of common items in the game, since eventually one single, specific item is required.
Box gacha
Box gacha is a virtual box of set items with known probabilities. Its popularity grew around the time that the kompu gacha controversy was becoming publicized. Box gacha is generally considered more fair because as items are pulled from the box, the likelihood of receiving the desired item increases, as there are fewer items in the box.
Sugoroku gacha
Sugoroku gacha is similar to that of a board game. Gacha mechanisms are used for the player to progress across the board, with further progress entailing better rewards. Each time that the player rolls the gacha, their character will either roll a dice or spin a wheel to determine how far the character will go.
Redraw gacha
Redraw gacha allows the player to "re-roll" the gacha if they receive an unfavorable result (This can also mean "re-rolling" on a new account over and over until you get the desired starting results to actually begin playing the game). Some games offer this feature for free.
Consecutive gacha
Consecutive gacha improves the chances of receiving rare rewards when the player spends in bulk. As opposed to spending a set amount for individual rolls, a player can spend a larger amount in order to roll several times in a row for a slightly discounted price. At the end of the roll, the player receives all the items at once.
Step-up gacha
With step-up gacha, the player's chances of pulling a rare item is increased each time they roll. This gacha is very popular with heavy spenders, because with every roll the stakes feel higher.
Open versus closed gacha
Gacha that show (open) versus hide (closed) the exact probabilities of pulling rare items.
Discounted gacha
Discounted gacha usually involve special campaigns or events by the game company to allow users to roll for a lower price.