Incremental games are video games whose gameplay consists of the player performing simple actions such as clicking on the screen repeatedly to earn in-game currency. In some games, even the clicking becomes unnecessary after a time, as the game plays itself, including in the player's absence, hence the moniker "idle game".
Gameplay
In an incremental game, a player performs a simple action – usually clicking a button – which in turn rewards the player with currency. The player may spend currency to purchase items or abilities that allow the player to earn currency faster or automatically, without needing to perform the initial action. A common theme is offering the player sources of income displayed as buildings such as factories or farms. These sources increase the currency production rate, but higher tier sources usually have an exponentially higher cost, so upgrading between tiers takes usually about the same time or even increasingly longer. Some games feature a reset-based system where the player resets the progress of their game and gains another form of currency. This new currency is normally used to gain global bonuses which do not disappear after a reset, allowing the player to go further than the previous reset. Incremental games vary as to whether they have a victory condition: games like Cookie Clicker allow the players to play indefinitely, while games like Candy Box! or Universal Paperclips feature endings that can be reached after a certain amount of progress is made within the games.
History
Incremental games gained popularity in 2013 after the success of Cookie Clicker, although earlier games such as Cow Clicker and Candy Box! were based on the same principles. In 2015, the gaming press observed such games proliferating on the Steam game distribution platform with titles such as Clicker Heroes.
Reception
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. 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. This leads to the player feeling powerful and weak at the same time in pursuit of exponential progress. Julien "Orteil" Thiennot described his own works as "non-games". In early 2014, Orteil released an early version of Idle Game Maker, a tool allowing customized idle games to be made without coding knowledge.