A loot box is a consumable virtual item in video games which can be redeemed to receive a randomised selection of further virtual items. A loot box is typically a form of monetization, with players either buying the boxes directly or receiving the boxes during play and later buying "keys" with which to redeem them.
A player's inventory of loot boxes and other virtual items is stored in a database run by the game's owners, and it is common to be able to view the items owned by other players either by seeing them equipped on in-game characters or by directly browsing others' item inventories. Some games also allow players to trade inventory items among themselves for other items, currency, or both.
Loot boxes are regulated under gambling law in some Asian countries. Elsewhere they are criticised for being a form of unregulated gambling often marketed to children.
Loot boxes are often given to players during play, for instance as rewards for levelling up their character or completing a multiplayer game without quitting. Players can also buy them directly. Some loot boxes can be redeemed immediately, while redeeming others requires further consumable items dressed as "keys".
Loot boxes are generally redeemed through an in-game interface which dresses the process with appealing visual and audio effects. Some such interfaces are explicitly modelled on slot machines or roulette wheels. When the player runs out of loot boxes or keys, a prominent button is displayed with which they can buy more.
The items that can be granted by a loot box are usually graded by "rarity", with the probability of receiving an item decreasing rapidly with each grade. While the set of items given are randomly selected it can come with certain guarantees, for instance that it will contain at least one item of a certain rarity or above.
Most loot box systems grant items without regard for what the player already owns. Means are provided to dispose of these duplicates, often involving trading them with other players or converting them into an in-game currency.
In some loot box systems, a set of "common" items can be combined once completed in order to form a rarer item. The first few items in a set can be rapidly acquired but as the number of missing items decreases in 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. Loot box systems of this nature are illegal in Japan.