Incremental game

[3][4] A common theme is offering the player sources of income displayed as buildings such as factories or farms.

[5] The resulting gameplay loop is simply to occasionally check in on the game and spend the currency you've gathered in the meantime.

[2] Some games include multiple layers of prestiging, thereby making new content, meta-currencies or gameplay available.

[citation needed] Pioneered by AdVenture Capitalist, developers may sell premium boost such as instant currency infusion (usually a percentage of current rate of income) or sometimes wrapped as a "time-warp" (instantly gain x-hours of future income), permanent boost multiplier that persist after each prestiging, instant prestige (claiming prestige without starting over), protection against negative events, gacha system (random draws of a character or a permanent bonus), and event currencies.

[5] On the other side, they may also deliver advertisements for players to receive minor rewards, such as short burst of cash, doubling offline earnings, small amount of premium currency, brief powerful boost/medium-length small boost, extra prestige points upon prestiging, relief of a negative status, etc.

[5] According to Anthony Pecorella in his GDC summit talks,[5] the creation of the genre was attributed to Progress Quest (2002) by Eric Fredriksen, which is a parody of the stat and auto-attack systems in MMORPGs.

Nathan Grayson of Kotaku attributed the popularity of idle games to their ability to provide unchallenging distractions that fit easily into a person's daily routine, while using themes and aesthetics of more sophisticated games so as to be appealing to a "core gamer" audience.

Grayson also noted that the genre allowed for a wide variety of game mechanics and themes, such as fantasy, sci-fi and erotica, to provide sufficient perceived depth to avoid boring players.

[13] IGN's Justin Davis describes the genre as being tuned for a never-ending sense of escalation, as expensive upgrades and items rapidly become available, only to become trivial and replaced by more.

[14] Julien "Orteil" Thiennot (creator of games such as Cookie Clicker) described his own works as "non-games".

[16] Commenting on the parodic nature of the genre, Pecorella commented that "[idle games is] a genre that's almost doesn't want to exist; it's a joke, but despite itself, keeps being really successful",[5] and on popular idle-games in general, "a lot of these are just glorified spreadsheet with some really neat mechanics in it.

Pecorella (2015) identified several genres that includes idle elements in their mechanics:[5] Shooting games, RPGs, and other genres also starts to introduce short prestige loop or mini idle games within, while some introduces offline progress to entice players to return, allowing for genre blends, from idle rhythm games to RPGs, to puzzle and dating sims.

Pecorella, in his 2016 GDC summit talk, argued that auto clickers are considered necessary by any "serious" idle game players, and that it's not cheating, but rather an exploration of an error in design.

Progress Quest (2002), considered the first idle game
An example of auto clicker software