The early 2000s saw a surge in different types of educational games, especially those designed for the younger learner. Many of these games were not computer-based but took on the model of other traditional gaming system both in the console and hand-held format. In 1999, LeapFrog Enterprises introduced the LeapPad, which combined an interactive book with a cartridge and allowed kids to play games and interact with a paper-based book. Based on the popularity of traditional hand-held gaming systems like Nintendo's Game Boy, they also introduced their hand-held gaming system called the Leapster in 2003. This system was cartridge-based and integrated arcade–style games with educational content.^[5]

The main purpose of serious games is education and training. Within education, there are many different subtypes, e.g. drill and practice games on one end and so-called "epistemic games" that help players learn to think like professionals on the other.
Other areas of serious gaming use include advertizing, political and religious propaganda, health (helping people in various ways with health issues), military, etc.
Aldrich (2009b) presented a diagram that defines serious games as a games genre that can include educational simulations

Copyright: Aldrich, C. 2009 http://www.innovateonline.info/ - reprinted with permission (click on the picture)

Martens (2008) cited by Ulicsak (2010) identified Game-based-learning (i.e. serius games) as the intersection of learninames and simulation.

Game-based learning according to Martens (2008), based on a figure in Ulicsak,

Breuer and Bente (2010) created a Venn diagram that we reproduced in slightly modified form and that identifes how serious games fit into the general "entertain education" area and how it relates to technology-enhanced learning (called e-learning in the original):

Serious games in the Landscape. Modified figure from Breuer and Bente (2010)

Entertainment education simply refers to the ida to make learning more enjoyable, e.g. by adding game design elements, though gamification or other similar means. Game-based learning refers to all sorts of games made for educational purposes. Digital game-based learning (DGBL) includes games that include learning as the main or sole purpose, both typical learning games of the 80's as well as large subset of modern serious games. The diagram shows that serious games may include other purposes than education. Edutainment can be seen as a subset of DGBL (as in the original figure), however we also left the possibility that edutainment can just refer to a kind of non-serious game (e.g. a title that may not harm your children)

Opposed to normal games, serious games for computers or played online follow implicit or explicit learning goals instead of pure entertainment therefore justifying their addition “serious” . Although they can contain elements of entertainment or competition (gamification), they usually apply these successful gaming mechanisms and its thereby increased level of involvement only to initialise gains in knowledge and competencies . So serious games (very often also called game-based learning or digital learning or educational games) can be called a link between (online or e-) learning and (computer) games where concrete classification is a matter of the particular context . The overall pedagogical concept in which it is solely the learner who becomes active whereas the teacher is just in charge of creating an inspiring reflexive learning environment can but doesn’t have to include representations or simulations of a piece of reality . Simulations like these also enable experimental learning, i.e. they can demonstrate processes that would have been too expensive, time-consuming or risky when implementing them in the real world ). Inevitable for them would be a reduction of reality in a didactic manner though (ibid.).