Incremental games are interesting and perplexing. Impressed by minimal player agency and periods of inactivity, they defy conventional logic about good game design, and able to attract a substantial player base. There are very simple, you click a button, a number goes up. You click it again, the number goes up again. You keep clicking, and eventually unlock something that makes the number go up for you.
Then the number keeps going up, even when you're not playing. Next, you repeat this process, forever. While they may seem simple, yet there is a depth of play and surprising addictiveness to them.
They appeal to a variety of playstyles as well, and there have been successful commercial and casual incremental games like Clicker Heroesand AdVenture Capitalist, as well as more experimental or hardcore examples like Candy Box, Cookie Clicker and Sandcastle Builder
Though there is substantial variation and experimentation in the genre, the fundamental aspects of the design concluded the presence of at least one currency or number; which increases at a set rate, with no or minimal effort; and which can be expended to increase the rate or speed at which it increases.
One of the distinguishing features of these games is that the number can increase without the player's direct involvement or even presence. This has led some to call incremental games "idle games," since they can be left to run and then returned to. While this is an important feature, I don't think its central to what defines these games or why players enjoy them. The unending upward growth of numbers is the most prominent feature, and so "incremental game" is a more useful title.
1) The Psychology of Increasing Numbers
There are some reasons, including two important ways that incremental games leverage unique facets of human psychology.
The first is a term that is commonly brought up in the story of incremental games: the "Skinner Box." Named (to his chagrin) after the behaviorist B. F. Skinner, these were experimental chambers he built to study behavioral conditioning of animal subjects. The "operant conditioning chamber" would typically house an animal participant who could produce a reward (like food) in response to performing an action (like pushing a button).
Notably, once the response mechanism has been learned, animals have been observed to repeat the food-producing action even if it only produces a reward after long intervals or even at random.
The second psychological underpinning of incremental games is our accumulation desire and loss aversion. Our brains are wired to hate losing things we have, and, conversely, to give us a strong desire to accumulate things. Incremental games work with both sides of this. Because the primary currency always goes up even when you're not playing, it reduces the stress caused by loss aversion: you can safely do something else for a while without the anxiety of the currency going away.
Additionally, coupled with our brains lack of numeracy skills, we can enjoy numbers that go up, even if those numbers lack external meaning. So, although it can seem ridiculous, a number that simply goes up can actually make us feel good.
2. Origins of the Genre
The earliest uses of the incremental mechanic were amongst the first generation of MMOs in the late 1990s. Because MMOs used a subscription model, they requested to entice players to play for as long as possible.
Some years later, social games would be the next gene of the incremental mechanic. Played primarily on Facebook, social games similarly needed players to play for as long as possible.
Particularly, the incremental mechanic became not only the reward system of these games, but often the entire game itself. One of the most successful of these was 2009's FarmVille. It was ostensibly a farming simulator, but contained very little resource management or strategic decision making.
Instead, the player buys plots of land on which to grow crops which can later be harvested and sold, and then the proceeds of which can be used to buy additional plots, and so on ad infinitum. At its height, it was playedby more than 80 million users.
3) Incremental Games Today
Many of today's most popular mobile games (the modern successors of social games) make use of incremental mechanics. The huge successful Clash of Clans(2013) is framed as a strategy war game, but the battling mechanic is fairly simplified and only forms a small part of the experience.
The main aspect of play to level up the village base by spending gold and elixir, both of which accumulate on their own, and can be made to accumulate faster with incremental upgrades.
4) Are These Even Games?
Incremental games are, in fact, games. We can set aside their immense addictive value for a moment, because while that shows why we might find them compelling on some level, it’s not the same as analyzing them as games. Games of most genres appeal to some visceral or subconscious area of their players, but that is secondary to what makes a game a game.
First, incremental games do have some non-obvious mechanics to unpack, most primarily that of discovery. In most incremental games, the player doesn't know the extent of upgrades they can buy, or know the upper bounds of the game's main number or the speed at which it can increase.
Exploring the limits of an interactive system is one of the hallmark qualities of how players experience a game, and incremental games are no exception. Even if they appearto be simple, they often permit vast exploration.
Candy Box in particular is arguably more about exploration and discovery than it is about incremental growth, despite that being its most obvious feature.
Secondly, while incremental games lay bare the vapidity of their premise ,it's the means to that end that can actually be engaging. Cookie Clicker, for example, does allow the use of strategy because there are number of ways the player can increase their "Cookies per second" metric.
So the "game" is about optimizing the system in pursuit of that goal. Most games actually have meaningless goals but it's the pursuit of them that's the fun part. Incremental games are just startlingly upfront about this convention.
In conclusion, I would say Incremental games have seen a popular game in recent years, and we are expecting to continue to see new examples, further exploration of the mechanic, and innovations on the premise. It would be a bad idea to remove these games as merely inexplicably addicting.
I hope the above critical examination and their history, we can come to appreciate their minimalist beauty and elegant execution. So keep an open mind and explore the form a little, and don't be surprised if the process takes a little while.