What is an idle game?

Where idle games came from

Progress Quest (2002) was a joke about role-playing games that played itself: the character fought, looted and levelled with no input at all. A decade later the joke became a genre. Candy Box and Cookie Clicker, both released in 2013 and both played in the browser, showed that watching numbers grow could be compelling when the player chose what to spend them on.

Cookie Clicker made the genre famous, and it is still the easiest way to see the whole idea at once: click a cookie, buy a cursor that clicks for you, buy a grandma who bakes, and before long you are buying time machines that bring cookies back from the past.

The loop at the heart of every idle game

Earn, spend, earn faster. You buy things that produce more of what you spend, so growth feeds itself. Sooner or later growth slows against a wall, and the game offers a reset, usually called prestige: give up your progress for a permanent bonus, and the next climb goes faster and further. See how prestige works for the details.

Many idle games also count time away: when you come back, they work out what you would have earned while you were gone. Others only run while they are open. Either way the rhythm is the same: short visits, each one a set of decisions.

Idle, clicker, incremental

The three words are used almost interchangeably. A clicker starts with you clicking for every point. An idle game progresses without you. Incremental is the widest term: any game built around numbers that grow and upgrades that feed them, idle or not. The article on idle versus incremental games goes into the difference.

What makes a good idle game

The next goal is always in sight: there is something to buy soon, and something bigger to aim for later. The choices matter: two upgrades that cost the same should lead to different runs. New layers change the rules instead of only adding zeros, and the game respects your time: it does not punish you for closing it.

Idle games in other genres

The idle loop mixes well with other genres. NGU Idle and Idle Slayer wrap it around an RPG; Kittens Game around a village builder; The Tower and Infinitode 2 around tower defense. Our own game, Marrow March, is an incremental tower defense: you place and train an army in front of a wall, assaults can run on their own, and a tree of permanent upgrades grows between them.