Sometimes it just clicks.

I had to delay this post last time, but if you are reading this it should now be fully published and done and I am back to my previous schedule.

Let’s talk about clicker and idle/incremental games, shall we?

Strategy Simplified

I think at their core, most – if not all – clicker / idle games are strategy games or at the very least closely related. This can be directly observed by comparing idle games to older browser games such as OGame (see screenshot). Where technical limitations reduce a strategy game to its core functionalities where all information is reduced to numbers and time.

German screenshot because the english landing page images are broken.

Idle Game, Clicker or Incremental?

Even though I use them quite interchangebly, they actually arent; A “true” clicker would focus solely on the active part of clicking while a “true” idle game uses clicks only to navigate or select/upgrade, not to actually play.

That said it’s fair enough to lump these two subgenre together as most games are a hybrid of these two and more than often also an incremental game.

Both have become quite popular, so dozens of new ones hit stores/sites like Steam and Kongregate every week.

So just for the sake of staying sane, unless otherwise stated I shall refer to all three subgenre, being idle, incremental and clicker game, to just “idle game”.

A growing list of Idle games on

My Experience

I’ve been intruiged by idle games for a few years now and played a bunch of them, some almost to the “end” of their content, some not far at all. Mostly to have something to play inbetween other tasks or to enjoy a bunch of crazy multipliers take my understanding of numbers to a whole new exponential level.

And I think some of these games have a mechanic or design that is worth pointing out; One thing right off the bat is the naming scheme, most games of these genres tend to be quite… upfront about their games core premise.

Naming usually includes some form of reference to the genre: Clicker, Grind, Idle, Incremental and so on.

Let’s go over some of these games and see what makes them special.

Cookie Clicker

The first and probably one of the most famous idle games that I have ever played, created by Orteil (

It’s really intriguing since it ticks all boxes so well; It starts off very click-heavy while transitioning slowly but surely into a more afk style of play where all the upgrades provide much more substantial boosts in CPS (Cookies per second).

I think this is pretty well done from a design perspective, the initial cookie clicking is enticing enough to keep you playing until you get your first upgrades, all the while showering you with achievements. This quickly turns into a spiral where you get obsessed with getting more of everything: more upgrades, more achievements, more prestige, more buildings, MORE COOKIES.

Early game of Cookie Clicker, I lost my savegame some time ago when I switched to my new PC. F

Clicker Heroes

This was the second proper idle game and another one that shot up in popularity soon after and for good reason(s):

Clicker Heroes looks a lot more like an actual game, not just a number simulator, it’s a lot more colorful has much more visual variety from the characters you can buy and upgrade to the enemies, bosses and their habitats.

It also features more meaningful decisions and choices for the player depending on their style of play. Compared to cookie clicker where you can technically calculate (and there is addons for that!) the best value building or upgrade to buy.

Clicker Heroes has Ancients that can be bought and upgraded to either server active gameplay (clicking) or passively (idle) gameplay, some also give you a chain for either, so the longer you idle or the longer you keep clicking the higher that bonus.

Which creates interesting ways to strategize, it’s also possible to respec but it’s not free and will set you back a bit, and I really like those choices.

Clicker Heroes Gameplay

Realm Grinder

I have neglected to talk about it, but I feel now is the time to talk about: Reset mechanics.

By Reset mechanics I mean those partial resets that those games offer in order to progress further by way of locking certain upgrades behind resetting at least once.

The idea is to stretch gameplay by making the player sacrifice most of their progress while rewarding them with ways of regaining it faster and going beyond.

Some games go so far and even add another more strict reset, these are often a milestone to reach and a vital part of progression later down the line, Clicker Heroes has “Ascension” and “Transcension” respectively.

Realm Grinder encorporates this in a very interesting way. It actually features three types of resets (by my last count): Abdication, Reincarnation and Ascensions. You can abdicate as much as you like, similar to other games, but Realm Grinder handles the tier two and three resets differently, they are fairly limited and rather unique in the way that they create interesting strategy opportunities for the player since they unlock a lot of different upgrades that can completely change the best build to use.

Also, should you be interested in Realm Grinder, this is it’s Steam page.
Also also, it has a great fansite created by G00FBALL that is worth checking out for strategies, builds and general information on the game.

NGU Idle

And finally we have NGU to talk about, in case you are asking it’s literally: Numbers Go Up Idle.

And the game is just as zero f* given as the title suggests.

NGU got quite popular recently and even released on steam. And while it certainly looks and feels a bit crappy, it certainly isn’t under the hood.

It borrows most of it’s core UI design and some of it’s mechanics from another Idle game called “Idling to rule the gods”. Which I don’t think is a good UX but it gets the job mostly done and could certainly be worse, especially considering that most these games are done by a single person that is probably more a programmer and less of an artist.

Top notch graphics… 11/10 would barf up jpegs again.

But to be completely fair: this is the quintessence of a lot of idle games, yes it’s about the fun you can have when numbers go up, no need to hide that. Also these games are simple enough that they can be easily done by a sole developer eager and creative enough to whip up something interesting for others to enjoy without having to rely on pretty assets or a well thought out story and characters, but retaining complexity and a sincere feeling of progression that some games just can’t offer the way incremental games do.

Speaking of developing Idle Games…

Programming an Incremental Game

In theory, developing an idle game should be rather easy; since most of the game is very repetitive by design and there is no need for sophisticated approaches to visual fidelity or sound design.

The more I played idle games, the more I noticed that this isn’t as simple as I thought, there are some technical and design challenges and limitations that are quite unique to the genre(s).


Oh the dread.. for the unaffiliated: 1.8e+308 refers to the highest number possible in most programming languages: 2^1024 which is precisely 1.7976931348623157e+308 a number with 308 digits.

For most cases no software has a reason to go anywhere near this number, but incremental games, by their very nature, have a tendency to do so.

There also isn’t really a lot that can be done about this, most developers either limit numbers to somewhere around 1e+300 or design their game around it. Let’s look at the examples from above:

  • Cookie Clicker doesn’t really solve this, it will just display “infinity” as that’s everything JavaScript will spit out when going beyond 1.8e+308
  • Clicker Heroes on the other hand, solves this pretty well, instead of relying on a single number to display/use they split their number in a precision float and a float for the exponent, giving Clicker Heroes essentially a theoretical limit of 10.0^1.8e+308 which is an absurdly large number, not infinite mind you, but so much more larger that it’s very unlikely that any player will run into issues. But it’s also a lot harder to program as it needs a custom number library and is a lot less convenient to use as a programmer.
  • Realm Grinder kind of solves the issue with it’s Ascensions, essentially (or rather ASCENTIALLY) removing some numbers from the game entirely such as gold costs and gold count. It’s a decent trick that can theoretically work an infinite amount of times but requires a lot more creativity and will inevitably obsolete every single number at some point.
  • NGU Idle – as far as I know – does not really go beyond 1.8e+308 it features a similar system to Realm Grinder in which there are difficulties (currently two) that are basically just harder resets compared to the normal resets (called Rebirths here) that slash the modifiers down as a “difficulty penalty” so the resulting numbers are smaller.
so ominous! (NGU Idle)

Having thought about this issue, I believe there is no perfect solution, I think out of the examples I would prefer the method Clicker Heroes’ developer have come up with, but it’s far from perfect. Ideally I think a dual approach could work where the underlying system can handle larger numbers where necessary (for example the main currency/resource) but secondary stuff is handled with careful design decisions so you don’t end up with a screen full of numbers so ludicrously large that they lose all meaning.

Idling Issue

And there is a second problem that is quite unique to incremental games: time. All these games are designed to be played for several days, weeks or months even, so not something you spend an evening or a weekend on and be done with it.

This results in two things players will most likely do:

  1. AFK / Tab out – When a game is called “Idle so and so” you can’t really expect the player to pay full attention all the time. Most players will minimize the window or switch tabs, this is usually not a problem but modern browsers such as Firefox, Chrome and Opera are optimized to run tabs that aren’t in the foreground with much less processing power (even if available), this means the game is running essentially in slow motion. Not ideal if you plan to (idly) bake all them cookies.
  2. Offline – Yeah go figure at some point everyone has to shut down the game, browser or the whole computer. Some idle games have logic in place to calculate at least some offline gains, but this does not work for every game or even every resource/thing in a single game. Luck based or proactive gains are especially unsuitable for this.

The former (Tab out) scenario can be a bit annoying, not an unsolvable issue but one that usually doesn’t really come up when designing or coding a game. I have created little test project that I called “Idle Souls”, where I tried to tackle this problem like this:

// Core game tickrate
function Tick()
	var time_new = new Date().getTime();
	var time_diff = time_new - last_tick;
	last_tick = time_new;
	resource_souls += time_diff / 1000 * test_per_second;
	window.setTimeout(Tick, tickrate - (time_diff - tickrate + 1));

My fix is pretty straight forward: I simply calculate the resource based on time passed instead of once per tick (because I can’t be certain that the tick rate is constant). It’s by no means a perfect solution but I can freely switch tabs on my browser without it impacting the rate at which the resource accumulates, so I call it a job done.

Balancing the Grind

A bit less technical but just as important is balancing these games. As I mentioned before this genre is by definition very unappealing so the game has to be well designed and balanced for it to still draw interest.

A huge factor in this is progress, if an idle game is poorly paced it might lead to a player not feeling any substantial gains for long enough to quit the game completely.

Soooo much to balance.

This is especially crucial since these games have to rely almost entirely on their layered mechanics, progression and depth to provide entertainment. So there is no story, no unfinished campaign or anything else to tow the player back into the game, should the mechanics fail to stay interesting.

Some games do have a nice community or steam achievements that might get some players to power through, but I reckon most players won’t care that much.

Some final thoughts

I think overall Idle games can be pretty fun and they definitely have a place for gamers, either because it’s something to enjoy passively while doing other things like watching videos or because it’s light entertainment/strategy and doesn’t require a lot of brainpower or attention, these games play themselves by design after all.

Especially nowadays where hundreds of games are released every month and nearly every new game has to be bigger, better and more exciting; A break from that pace without missing out on new experiences can be very welcome.