Why Hearthstone is so Addictive: 6 Lessons for Non-Game Mobile Apps
User engagement and retention lessons from Blizzard‘s massively successful card strategy game.
Hearthstone: Heroes of Warcraft is a PC and mobile card strategy game by Blizzard Entertainment, and arguably one of the most addictive apps in the app stores. Over 30 million people have played this fun, gorgeous game since it launched about a year ago, and millions more tune into livestreams to watch people battle each other.
Hearthstone uses clever tactics to compel players to return multiple times a day, and many of these principles could also work for non-game apps.
Below, I’ve listed some of the underlying concepts that make the Hearthstone app so sticky. I hope that by cataloging and exploring these ideas, I’m able to better understand them and bring them to my own work as a product designer and product manager.
6 Ways the Hearthstone Mobile App Keeps Players Coming Back
- Beginnings matter: when onboarding new users, show, don’t tell.
- Offer various “play” modes: provide value for both content producers as well as content consumers.
- Surprise every time: variable rewards keep people coming back.
- Celebrate user achievements: people love getting (virtual) high fives.
- Customization: a user who creates something in — or with — the app is a lot less likely to abandon it
- The power of sound: good sound designs helps make an app memorable.
1. An Effective Onboarding Experience Helps the User Perform Key Actions for the First Time
You’re welcomed into Hearthstone by an exuberant “Innkeeper” whose kind voice guides you through an onboarding tutorial.
This tutorial takes the form of short mini-games — each one explains a different aspect of how to play Hearthstone until you have all the basics down. This is what the first 3 mini-games look like:
It’s important to note that the full tutorial is NOT short. In fact, I’m pretty sure it took me nearly an hour to complete, which goes against a lot of the advice I’ve seen to get out of the way as quickly as possible.
I think the reason a long tutorial worked for Hearthstone is because it never felt like a tutorial.
Instead, it felt like…well, a game. Simple, short, fun games that aligned perfectly with my reason for installing the app in the first place — to have fun.
Note to self: Onboarding tutorials shouldn’t feel like work. Gamify them and make them as interactive as possible. Don’t just tell users how to do something, show them by making them perform important actions at least once.
Note to self: Don’t be afraid to try a longer onboarding process. Focus less on keeping it short, and more on helping the user perform core actions that immediately provide value.
2. Create Different Levels of Engagement Intensity for Different Kinds of Users
One of the best things about Hearthstone is that it’s fun for all kinds of users — everyone from casual players to hardcore gamers. This is because there’re multiple different ways to engage with the app.
Here they are, in ascending order of effort required by the user:
LEVEL 1: Spectator mode — This is when you watch another user play the game. This level of engagement is all about passive consumption. The only effort required of you is to keep your eyes open.
LEVEL 2: Play against the computer (Single player PRACTICE MODE)— At this level of gameplay, you battle against the computer on Normal or Expert mode to hone your skills.
LEVEL 3: Play against the computer (Single player ADVENTURE MODE) — Users can play “adventures,” which are a collection of games that follow a scripted narrative. In an adventure, you’re pitted against computer-controlled opponents with unique powers and cards. You earn rare cards when you defeat these villains.
LEVEL 4: Play against a human (Multi-player CASUAL MODE) — This is when you spar with other human players for fun. You can win prizes, and the stakes are relatively low.
LEVEL 5: Play against a human (Multi-player RANKED MODE) — In ranked mode, the outcome of the battle determines your rank on the global leaderboard. Success comes with glory and perks, and losing a battle means falling lower in the rankings, so the stakes are high.
LEVEL 6: Play against a human (ARENA MODE) — Arena mode takes the intensity of playing against a real person and cranks it up to 11.
First, you must purchase entry into the Arena, either using in-game currency (gold) earned from defeating dozens of other players, or real-world currency. Next, you don’t get to use any of your carefully-prepared card packs. Instead, you must construct a new pack on the spot with cards you might never have seen before.
You’re then launched into back-to-back battles with accomplished players — three losses, and you’re out of the Arena. The longer you last in the Arena, the better the loot you earn at the end.
By providing multiple ways with which to interact with the app, Hearthstone ensures that there’s always something fun for a user to do, regardless of how little time they have.
(Facebook offers another good example of this idea in action. The Facebook Like button is a very low-effort user action — one tap, and you’re done. Creating an album with 100 tagged photos, however, is a much larger ask.
By providing the lower-effort option, Facebook creates an opportunity for even casual users to engage.)
Note to self: Allow both casual as well as power user to gain value from your app. What would a ‘consumption-only’/spectator mode of your app look like?
3. Use Variable Rewards to Keep People Coming Back
In his book, Hooked: How to Build Habit-Forming Products, Nir Eyal lays out a framework for making sticky products. It’s a behaviour loop consisting of:
- an external trigger
- an action
- a variable reward
- an investment by the user
- and an internal trigger
Here is Anthony Kosner explaining the Variable Reward portion of the model for Forbes:
It is important that the product reward the actions that it triggers, but critically, if these rewards are variable we are far more likely to get sucked in. Decades of brain research has concluded that we are more motivated by the anticipation of reward than by the reward itself. In Flappy Bird, most of the time you fail, but the possibility that you could get a high score (or any score at all!) deepens the hook… both Flappy Bird and Pinterest successfully utilize multiple types of rewards — but always with some degree of variability.
This idea of variable reward also explains why apps like Facebook, Twitter, and Tumblr are so addictive. Every time you open the app, there’s something new to see in the feed — a variable reward that keeps you coming back.
Variable rewards are something Hearthstone does extremely well. Here’re numerous examples:
1. New daily quests reward players for returning every day. Players get gold (in-app currency) for winning quests, which can be used to purchase more powerful cards. There‘re new quests every day, so the player is motivated to check in to see the new quest.
(Side note: Another great thing about daily quests: Hearthsthone cleverly ties daily quest rewards into an extended tutorial flow. For example: Hearthstone saw that I hadn’t yet tried the “watch someone else play” feature, so it made using that feature a requirement of a daily quest, which incentivized me to try out the feature for the first time.)
2. For the first 20 levels of any character class, you win a random new card for every two levels you progress. Some of these cards can be rare and powerful, so there’s an incentive to keep playing to unlock new cards.
3. In ranked mode, the more battles you win, the higher you rise in the global rankings. Each new rank comes with a brand new badge indicating your increased skill level. Like all of Blizzard’s art, the badges are gorgeously designed, so there’s a small rush when you ascend into a higher rank and see the badge art for the first time.
4. When you earn or purchase a new card pack, the pack contains a random assortment of cards, some of which are extremely rare or even legendary. Opening a pack is an exciting unboxing experience, arguably on par with unsheathing a brand new phone from the box. People get really into it, such as this guy ☺ (warning: brace yourself for loud screaming and joyful swearing in German)
5. When you complete a campaign in Arena mode, you can win a wide variety of prizes. You have no idea what you’ll get — the only thing you know for sure is that the longer you last in the Arena, the more epic your reward.
The above are all examples of the variable reward principle in action in Hearthstone.
Note to self: Wherever possible, introduce a variable reward element into your app. It can be something like an activity feed that always has new content, or an incentive system (eg. badges) for accomplishing a feat. The important thing is to make it so that every time the user opens the app, they see something new.
4. Celebrate User Achievements, Both Big and Small
Hearthstone is generous with praise.
The app loudly recognizes when you do something for the first time, or when you hit milestones, many of which are relatively easy to attain.
It’s not unusual to see some sort of high-five multiple times in a single app session, and the constant praise doesn’t get boring. It’s a constant stream of positive reinforcement.
People love receiving high-fives, even virtually, and they’ll keep coming up for a taste of that positive reinforcement.
Note to self: Celebrate user milestones often and loudly. This is another place where an internal incentive system (eg. virtual gold or badges) can come in handy as positive reinforcement.
5. If the User Creates Something In or With the App, They’re a Lot Less Likely to Abandon It
Here is Kosner again, explaining the Investment part of Eyal’s Hooked model:
Finally, for the habit to really take hold, the user has to invest into it. The pictures you take with Instagram constitute your investment in the platform. Not only does the threat of losing this body of work keep you from switching to other photo apps, but your social engagement with others on the platform reinforce this continuity as well.
Hearthstone does a phenomenal job getting users to make incremental investments of time and effort (and even money) in the app. Here’re some examples:
1. Creating a card deck: winning games in Hearthstone relies on having a solid deck of cards. Each player can own a maximum of 9 decks, and each deck can contain 30 cards. That adds up to literally thousands of possible card combinations per deck, and it’s easy for even a casual player to invest many hours into putting a deck together and optimizing it over time. Once you put so much mental energy (and possibly cash) into creating your dream deck, you’re a lot less likely to delete the app and abandon the fruits of your labour.
2. Customizing the look of your cards: Hearthstone lets players add a touch of individuality and personal flare to their card in two ways. Firstly, you can change the design of the back of your card, so that it doesn’t look like everyone else’s.
You can also get special gold cards, which also don’t come with any additional abilities, but they’re cool-looking enough that some players play a metagame where they attempt to put together decks made of all-gold cards.
Small card customizations make it a little less likely that the user is going to delete the app and abandon their creation.
(Bonus retention tactic: Every month, the most engaged players get a custom, themed card back. Players use card backs to subtly signal expertise, so each month, players are incentivized to play for as long as they need to in order to be eligible for that card back. This, of course, increases Hearthstone’s engagement and retention numbers.)
3. In-game currency: Gold is the in-game currency of Hearthstone. You earn it by winning battles and completing quests, and you can spend it on new cards, purchase access to the Hearthstone Arena, and buy Hearthstone Adventures.
After a few days of playing Hearthstone, you can amass a sizeable amount of gold very quickly and it’s hard to walk away from all that gold, even if it’s entirely virtual.
Note to self: It’s very important for the user to invest some measure of time and effort into the app by taking some action, no matter how small. It’s a virtuous cycle — the more they do something inside the app, the more likely they are to return. This is another reason why the onboarding experience should be interactive rather than passive.
A user making an “investment” in the app can take multiple forms:
- Adding a bio
- Following friends on the network
- Customizing the look and feel of their profile
- An in-app “trophy cabinet” to display in-game rewards
…literally anything that gets them to perform some sort of action while inside the app.
6. Good Sound Design Helps Make an App Memorable
A few weeks ago, I noticed an odd bug in my Hearthstone app — the sound had stopped working. It was only then that I realized just how much sound contributes to the Hearthstone experience.
Here’s a supercut of all the atmospheric music that plays on loop at various points in the app:
You don’t realize it until it’s gone, but there’s an aural component to literally every part of Hearthstone. In addition to the theme music, every card played comes with a custom audio battlecry that adds a ton of personality.
This is what it looks and sounds like when a card is played (this is a supercut of card animations):
And this is a convenient catalog of many of the sounds of individual cards:
Literally every aspect of gamplay is improved with sound. It gives the app personality and helps make it memorable. Take away the sounds, and Hearthstone is suddenly a dramatically less compelling experience.
Sound isn’t only important for games. Even non-game apps can be improved with the judicious use of sounds. Earlier this year, Facebook introduced little sounds tied to key actions:
Josh Constantine of TechCrunch explains why Facebook likely introduced these sounds:
It might not seem like a big deal, but any game designer can tell you how important sounds are to creating an immersive, addictive experience. It’s the reason most freemium social games are filled with encouraging noises designed to make you feel good about yourself as you spend money on virtual cows. That same quirk of human perception could get people spending more time on Facebook, seeing its ads while they connect with friends.
Note to self: Including sound in a smart way in your app is a great way to engage more of your user’s senses and make a memorable impression. Think through key actions or animations in your app — can they be improved with a little sound?
Conclusion
Hearthstone: Heroes of Hearthstone uses some really smart tactics to keep players returning to the app, and bringing these ideas to your non-game app could help make your product as sticky as any viral game.
Do you have favourite examples of retention tactics from other mobile games. Please share.
If you’d like to discuss these ideas further, kindly shoot me an email at equartey@gmail.com.
