Life simulation game

Life simulation games form a subgenre of simulation video games in which the player lives or controls one or more virtual characters (human or otherwise). Such a game can revolve around "individuals and relationships, or it could be a simulation of an ecosystem". Other terms include artificial life game and simulated life game (SLG).
Life simulation games are about "maintaining and growing a virtual life", where players are given the power to control the lives of autonomous people or creatures. Artificial life games are related to computer science research in artificial life. But "because they're intended for entertainment rather than research, commercial A-life games implement only a subset of what A-life research investigates." This broad genre includes god games which focus on managing tribal worshipers, as well as artificial pets that focus on one or several animals. It also includes genetic artificial life games, where players manage populations of creatures over several generations.
Artificial life games and life simulations find their origins in artificial life research, including Conway's Game of Life from 1970. But one of the first commercially viable artificial life games was Little Computer People in 1985, a Commodore 64 game that allowed players to type requests to characters living in a virtual house. The game is cited as a little-known forerunner of virtual-life simulator games to follow. One of the earliest dating sims, Tenshitachi no gogo, was released for the 16-bit NEC PC-9801 computer that same year, though dating sim elements can be found in Sega's earlier Girl's Garden in 1984.
In the mid-1990s, virtual pets such as Petz and Tamagotchi began to appear. Around the same time, Creatures became "the first full-blown commercial entertainment application of Artificial Life and genetic algorithms". By 2000, The Sims refined the formula seen in Little Computer People and became the most successful artificial life game created to date. In 2007, the game Spore was released, in which the player develops an alien species from the microbial tide pool into an interstellar empire.
Digital pets are a subgenre of artificial life game where players train, maintain, and watch a simulated animal. The pets can be simulations of real animals, or fantasy pets. Unlike genetic artificial life games that focus on larger populations of organisms, digital pet games usually allow players to interact with one or a few pets at once. In contrast to artificial life games, digital pets do not usually reproduce or die, although there are exceptions where pets will run away if ignored or mistreated.
Digital pets are usually designed to be cute, and act out a range of emotions and behaviors that tell the player how to influence the pet. "This quality of rich intelligence distinguishes artificial pets from other kinds of A-life, in which individuals have simple rules but the population as a whole develops emergent properties". Players are able to tease, groom, and teach the pet, and so they must be able to learn behaviors from the player. However, these behaviors are typically "preprogrammed and are not truly emergent".
Game designers try to sustain the player's attention by mixing common behaviors with more rare ones, so the player is motivated to keep playing until they see them. Otherwise, these games often lack a victory condition or challenge, and can be classified as software toys. Games such as Nintendogs have been implemented for the Nintendo DS, although there are also simple electronic games that have been implemented on a keychain, such as Tamagotchi. There are also numerous online pet-raising/virtual pet games, such as Neopets. Other pet life simulation games include online show dog raising games, and show horse raising games.
Some artificial life games allow players to manage a population of creatures over several generations, and try to achieve goals for the population as a whole. These games have been called genetic artificial life games, or biological simulations. Players are able to crossbreed creatures, which have a set of genes or descriptors that define the creature's characteristics. Some games also introduce mutations due to random or environmental factors, which can benefit the population as creatures reproduce. These creatures typically have a short life-span, such as the Creatures series where organisms can survive from half an hour to well over seven hours. Players are able to watch forces of natural selection shape their population, but can also interact with the population by breeding certain individuals together, by modifying the environment, or by introducing new creatures from their design.
Another group of biological simulation games seek to simulate the life of an individual animal whose role the player assumes (rather than simulating an entire ecosystem controlled by the player). These include Wolf and its sequel Lion, the similar WolfQuest, and the more modest Odell educational series.
In addition, a large number of games have loose biological or evolutionary themes but do not attempt to reflect closely the reality of either biology or evolution: these include, within the "God game" variety, Evolution: The Game of Intelligent Life and Spore, and within the arcade/RPG variety, a multitude of entertainment software products including Eco and EVO: Search for Eden.
Social simulation games explore social interactions between multiple artificial lives. In some cases, the player may simply be an observer with no direct control but can influence the environment of the artificial lives, such as by creating and furnishing a house and creating situations for those characters to interact. These games are part of a subcategory of artificial life game sometimes called a virtual dollhouse. The Sims is the most notable example of this type of game, and was itself influenced by the 1985 game Little Computer People.
In other games, the player takes a more active role as one character living alongside other artificial ones, engaging in similar life pursuits as to make money or sustain their character while engaging in social interactions with the other characters, typically seeking to gain beneficial relations with all such characters. Several of these fall into the subgenre of farming simulations, where the player-character runs a farm in a rural setting, growing crops and raising livestock to make money to keep their farm going while working to improve relations with the local townspeople. Such games include the Story of Seasons and the Animal Crossing series, and Stardew Valley. Dating sims are related to this type of game, but generally where the play-character is seeking a romantic relationship with one or more computer-controlled characters, with such titles often aimed at more mature audiences compared to the typical social simulation game. Dating sims may be more driven by visual novel gameplay elements than typical simulation gameplay.
Some games take biology or evolution as a theme, rather than attempting to simulate.