Guest Post: Clash of Clans engagement analysis

Supercell logo

Editor’s note: Clash of Clans, one of two titles from Finnish mobile developer Supercell, has continually topped the iOS charts and raked in loads of money for the studio. Kevin Oke, Lead Designer at both Adrian Crook & Associates, a social-mobile game design consultancy, and PlayRank, a second screen startup, takes a deep dive into how Clash of Clans effectively engages and retains players.
Supercell logo

Supercell’s Clash of Clans (CoC) has been a top grossing title on the iOS app store for months now, and in the course of playing (and becoming addicted to) the game, I began to unravel just how it manages to engage and retain players so well.

Meaningful Downtime Mechanics

Games relying on appointment mechanics as part of their compulsion loop typically have trouble addressing the downtime that arises in between these appointments. Specifically, how to engage players during this time, as generally the most engaging gameplay and core mechanics are intertwined with these downtime-creating appointment mechanics. In city builder games, usually the only thing available to the player during downtime is re-organizing their cities — shallow gameplay, generally speaking.Clash of Clans downtime screenshot

In this sense, CoC is no different. However the composition of the player’s village is not only vital to success, but a downtime session of moving gold mines and cannons around can directly lead to a micro-transaction.

A quick explanation for those that have not played CoC: The layout of your buildings, walls, traps, and weaponry are key, as you need to defend against raids from other players. An airtight defense quickly becomes the obsession of CoC players as they try to protect their stores of gold and elixir. Using the Replay feature (more on this later), they watch and learn from their defeats, tweaking their layout to patch holes in their defense.

In short, this is a fantastic downtime mechanic. Why?

  • It’s meaningful.
  • It creates additional, long play sessions (a level 20 player could easily spend half an hour doing a total revamp of their defenses).
  • Spurs on purchases — “I could defend the south side of the village with just these two cannons if they were upgraded. But I don’t have enough gold … But if I don’t upgrade, I’m too vulnerable.” A perfect example of this mechanic leading to a micro-transaction.
  • The player’s fortress layout is personal and unique. This attachment is great for engagement long-term.

As you can see, this isn’t just a fantastic downtime mechanic, but a fantastic gameplay mechanic period.

Loop Optimization

Loop optimization provides the player with tricks to discover and exploit over the course of their lifetime within the game. A prime example in social games is Farmville players finding and planting the seeds with the best coin/XP cost ratio. Instances of loop optimization help with long-term engagement by making a game more difficult to grok, and in competitive games, providing an edge to players with the will to unearth them. In social games with appointment mechanics, they also create more sessions per day.

Loop optimization in CoC is centered on resource collecting and raids. In classic appointment mechanic fashion, for the player to most efficiently harvest gold and elixir they need to return to the game and harvest right when the resource generating structures are at max capacity. Harvest any time past that point, and it’s the equivalent of turning on a tap to fill a bucket and leaving, coming back, and seeing the bucket overflowing — wasted resources. This is not unique to CoC in any way, but it’s still important in maximizing the number of daily sessions per player.

The more interesting loop optimization comes from player vs. player (PvP) and the threat of raids. Leaving hoards of gold and elixir sitting around makes the player a very appealing target for raids. Thus they are encouraged to check in often and do one of two things:

  • Collect their resources from the buildings that generate them, moving them into their storage units, which if the player is smart, are behind fortifications.
  • Collect and spend their resources immediately.Clash of Clans lopp optimization screenshot

As the player can only build a certain number of defenses at any given time (based on the level of their town hall), they can never provide adequate protection for all of their structures.

Thus the need to check in often and spend, or move the gold and elixir to storage units that are better protected — it’s a common strategy to keep storage units behind walls and near archery towers and cannons, and leave gold mines and elixir collectors out in the open, as they store much less and therefore are less of a loss if pillaged.

This all means that saving up for big-ticket upgrades and buildings is risky. The more time spent saving up, the bigger the loss and time wasted if the player is raided. Recognizing that a moment of tension and risk is a great time to conduct a micro-transaction, Supercell offers a shield that will protect the player from raids while they are saving up. Or the player can just buy the item in question immediately with hard currency.

Replay Feature

The replay feature was added to CoC in an update, and in short, it’s brilliant. Allowing the player to see first-hand how they got raided by pointing out the weak points in their fortifications makes them spend more time and money in-game adjusting their defenses. It functions as a useful tutorial, of sorts.Clash of Clans replay feature

Push Notification Strategy

CoC’s push notifications are useful, draw the player back into the game for another session and aren’t spammy. Push notifications telling the player that their village has been raided are particularly effective at creating both new sessions and monetization. Stolen resources set the player back in the “harvesting” portion of the game loop, which can lead to micro-transactions by impatient players wanting to catch up.

You would be hard pressed to ever want to turn off the game’s push notifications because of this balance of utility and unobtrusiveness. I believe this restrained approach has been taken because the threat of PvP raids creates an organic source of notifications that, if combined with too many “hard coded” ones, could have become annoying.Clash of Clans push notification


Behind the gaudy revenue that it brings in (Supercell reportedly makes approximately $1 million a day between its two iOS titles), Clash of Clans is a highly engaging game with an especially tight game loop and economy that deserves every designer’s attention. Although it is still lacking a cohesive social experience, even the most cynical opponents of free-to-play games can see the care and attention that has gone into creating it.