Within any specific game, there are various forms of currency, but it usually works out that there are two to three types of currency. The first type of currency, which I’ll call the primary currency, is the most easy to accrue. It usually exists within the game and is collected during the game play. For instance, for an endless runner game, the currency is in the path of the player waiting to be collected. For a city or civilization building game, currency is produced by a factory, mine, etc. and slowly builds up over time. These “factories” can be improved to yield a better economic output.
A secondary form of currency is rarer to collect. It doesn’t normally appear in the game, but can be collected in various ways: the most common way is through purchasing online. Other ways are usually as a form of daily reward, or lifetime achievements (for instance, as a form of reward for doing X action a lot of times). Sometimes, there is a third rare currency available to enable certain special actions, which can only usually be purchased.
Some examples of game currencies are the following:
- Clash of Clans – Primary currency exists as gold/elixir, and secondary currency exists as gems. Primary currency is earned over time as produced by gold mines and elixir stations. Gems can be used to speed up the progress.
- Boom Beach – Primary currency exists as gold for purchases, wood/stone/iron for producing buildings. Diamonds are available as a secondary currency and can be used to speed through the game.
- Spiderman Unlimited – The primary currency are vials, with a secondary currency of ISO-8. Vials are collected during the course of running in the game, while ISO-8 is earned for completing levels.
During the game, the “economies of scale” usually favor a quicker accumulation of the primary currency, a slower accumulation of a secondary currency, and a purchase only accumulation of a tertiary currency. If you are unfamiliar with the term “Economies of Scale”, is defined as the following in Wikipedia:
In microeconomics, economies of scale are the cost advantages that enterprises obtain due to size, output, or scale of operation, with cost per unit of output generally decreasing with increasing scale as fixed costs are spread out over more units of output.
… For example, a large manufacturing facility would be expected to have a lower cost per unit of output than a smaller facility, all other factors being equal, while a company with many facilities should have a cost advantage over a competitor with fewer.
While we aren’t dealing with businesses or manufacturing, from a game design perspective, economies of scale can refer to paid vs. free users. There will be users that buy the game or pay for in-game currency to get ahead faster in the game, while other users will take a slower track and earn all currency. A good economy of scale with these two types of users should obviously slant to players willing to pay money in order to take the fast track, while making sure to offer an incentive to play the game for free users.
Incentives appear in many forms; some are the following examples:
- They may be daily rewards for coming back to play the game day in and day out.
- Special game modes can be made available that offer a higher level of currency than usual, but which is only available for a short period of time. These add some variances to the game