One of the most common Monetary Dark Patterns is the use of premium currency. This is when real money is exchanged for in-game currency. It could be gems, tokens, crystals, coins or anything else specific to the game. This in-game currency is then used to purchase items, upgrade weapons or otherwise play the game. Usually, no limits are placed on the amount of premium currency that can be purchased, which can lead to some addicted players spending huge sums of money on the game. In the industry, these types of players are called "Whales" because of their big spending. Historically, less than 2% of a game's players will spend money on a free to play game with premium currency.
There are several reasons why this is a Dark Pattern:
First, the exchange rate between real money and the premium currency often disguises the real price of items that you purchase in the game. This is compounded by the fact that purchasing larger bundles of premium currency often gives you a better exchange rate. Because the true price of the in-game item is disguised by the variable exchange rate, player's aren't as aware of how much they are spending, and end up spending more.
Second, because of another dark pattern called Waste Aversion
, people are reluctant to leave a small amount of unspent premium currency. Game developers know this and they often price items in such a way that you will always have some unspent currency. For example, you may only be able to purchase gems in bundles of 1000, but items cost 80 gems inside the game. This means you'll have 40 gems left over and may feel like you need to purchase more gems to try to even it up and get down to zero.
Third, some countries have laws against gambling, which would make it illegal for the game to sell Loot Boxes
for real money. Because premium currency isn't real money, game developers can claim that loot boxes aren't gambling and they can get around the laws. Loot boxes are a powerful money-making technique for game, so using an intermediary currency to get around the law allows games to continue to including gambling in their games when they would otherwise be prohibited.