Idle Games form an intriguing genre that defies typical game design wisdom in many ways while still being incredibly successful. Now, as a genre that is three years old, idle games are starting to demonstrate more and more sophistication and depth of mechanics, bigger budgets and licensed IP, all the while being led by innovative indie developers. My talk at this year's GDC, "Idle Chatter," gives an overview of old mechanics, new mechanics, and how idle mechanics might work even in other games. Additionally, the full video of my 2015 GDC talk, Idle Games: The Mechanics and Monetization of Self-Playing Games, has been made available by GDC. This post is not going to be a full explanation and transcript, but it will explain some of the highlights.

The Magic of Exponential Growth

While progress without interaction is what the genre is named after, the secret that makes it all work is exponential (or perhaps high-degree polynomial) growth. Al Bartlett famously said, "The greatest shortcoming of the human race is our inability to understand the exponential function." Idle games use this, among other mechanics, as a way to keep progress interesting and exciting. The properties of growth at this rate yield a few significant results:

• Large numbers, which are fun for us
• Substantial growth benefits from checking in quickly to make a few adjustments
• Natural back-and-forth between costs and income
• High income accumulation after being away for a long time (growth of upgrade costs outpaces this quickly, removing the need to punish time away from the game)

But perhaps most importantly, it enables the fairly unique concept of a game reset, often called a "prestige." The player resets to 0, but with a multiplier on their growth. This multiplier allows the player to fly through the previous content, but still run up against a later "wall" as the exponential growth of upgrade costs catches up.

New Features

Major innovations over the last year have focused heavily on making the prestige loop more interesting. Rather than simply "faster, then even faster!", there is now often variation in gameplay through each prestige reset. Players may choose a different set of powers, have a particular goal to attain, or even earn a "meta prestige" by resetting their prestiges. One game is even exploring "meta meta prestiges." Yeah, I know; it's crazy, but it works.

The other primary source of innovation has been around player decision and complexity. We're seeing two-dimensional layouts that require planning and strategy to maintain and optimize. There are also specific goals to work toward that the player has to prepare for, and groupings of options (like forming a party of heroes) that the player must choose from to form the best combination for a particular task. In short, the games are maturing beyond the initial fascination with exponential growth, now wrapping that still-compelling feeling with more-traditional game mechanics.

Idle Mechanics for Non-idle Games

While the idle genre is now drawing inspiration from non-idle games, we're seeing the opposite direction too. Things like short prestige loops are seen in launch games, shooters, and RPGs. Some games are embedding mini idle games within them, and others are providing offline progress to entice players to return. There's also a trend of genre blends, combining more "true" idle game mechanics with other genres from rhythm games to RPGs to dating sims.

Conclusion

The idle game genre is an intriguing one and is particularly approachable by smaller developers. Kongregate is one of the best homes for idle games on the internet and we strongly encourage you to try one out and see how players respond. And if you have any questions about trying to generate revenue for your game, hit us up at apps@kongregate.com. We look forward to seeing what you guys and gals come up with!