The Wise Owl and the Angry Bird

What Duolingo teaches us about using fiero in app design

By: Sam Liberty

I am a serious game designer and consultant. Recently, I wrote about the game design concept fiero as it applies to UX and engagement, in contrast to the more widely publicized psychological concept of flow. In that article I called out a few apps that make use of fiero such as Foursquare, Medium, and Duolingo. In this article, I intend to break down Duolingo’s use of fiero, show how the app is able to generate it, and talk about how it could be leveraged further to drive engagement.

Refresher Course: What is Fiero?

If you can already answer this question, go ahead and skip this section. Unless you’re a completionist, in which case is this ever the right article for you.

Fiero is the thrill of excitement we get when we achieve something difficult, like scoring a point in tennis against a tough opponent, beating a boss in a video game, or getting an A on a test.

I talk about fiero in a little more detail in my last article on the topic, but if you’re really curious about it, take a look at former Magic designer Zac Hill’s article on the topic, Sculpting Flow and Fiero.

I previously made the point that this feeling is relatively easy to create and drives engagement well in popular games like Monopoly and Settlers of Catan, going so far as to credit their success to their ability to manage this emotion. In addition to these popular tabletop games, many smart phone apps use fiero to great, almost addicting, success. Candy Crush is a famous one, but I’d like to take us on a detour today through Angry Birds.

Why Angry Birds Drives Us Mad

Angry Birds [AB] is the mobile-game super hit that virtually defines time wasting and addiction (in the positive sense, of course). With more than three billion downloads and an entire spin-off franchise, the designers must have been doing something right.

Angry Birds

Good character design is certainly helpful, but I’d argue the main thing that AB is does successfully is build cycles of fiero for the player. The level design, structure of the game, and feedback framework all work together to accomplish this.

Here are some specific ways that Angry Birds successfully triggers the feeling of fiero:

  1. Many well-designed levels of play which grow progressively more difficult
  2. Infinite attempts to pass each level
  3. Very fast gameplay loop
  4. Strong positive feedback for success
  5. Tiered success (1, 2, and 3 stars to pass each level “perfectly”)

If you have even a passing understanding of the term, it’s clear how these features combine to create strong and frequent feelings of fiero. These design elements also are not unique to AB — these days, they are practically de rigueur for mobile phone games.

Is Level 3–9, Trick of Treat, the most difficult of all time?

Enter the Owl

The remainder of this article will examine how Duolingo captures the feeling of fiero well and how it could be done better. Interestingly, Duolingo is the rare gamified app that actually has the opportunity to create the more elusive experience of flow, since language learning is inherently challenging. The app incorporates many gamification lessons. Here are a few:

*Awarding in-game currency for completing lessons
*Purchasable upgrades and “power-ups”
*A “percent fluent” award that pops up at milestones
*Levels of tiered difficulty
*A “streak” counter for days of engagement with the app

Can you think of any I missed? Let me know in your responses to the article.

Translation: “You gained 2 lingots!”

Let’s examine each of these in turn and analyze what they’re doing. First: in-game currency. Whenever you complete a task in Duolingo you are rewarded with some number of an in-game currency called “lingots.” This by itself does not do much to create fiero. Although it’s nice to get stuff, just letting it pile up won’t give users the feeling of accomplishing something difficult. However, you can spend your lingots on power-ups, which not only makes them useful, but begins to create a sense of fiero.

Once a user decides they want to purchase a power-up, the lingot cost of that power-up becomes a de facto goal for the player. Thus, a user might decide to continue playing longer so they can reach that threshold. Achieving this goal creates a small amount of fiero for the player, but is limited by the number of power-ups in the lingot store. Currently, available power-ups include:

*Streak Freeze (lets you keep your streak even if you miss a day. More on this later)
*Double or Nothing (lets you set a goal for yourself and rewards you for making it)
*Heart Refill (lets you complete a lesson in the app with more mistakes)

Some of these may be appealing to different user types, but a lack of variety and “higher-tiered” power-ups means that any goal set must be relatively modest. Thus, the feeling of fiero for reaching the threshold will be modest as well.

The Shop: strong gamification elements in Duolingo

Of special note is the Double or Nothing power-up which allows you to challenge yourself to use the app for X number of successive days. This is a more powerful way that Duolingo creates fiero, since achieving the streak is challenging, and the reward for doing so is large (double your lingots). But again, since the lingots are only useful for buying the other power-ups, the feeling of accomplishment can be muted.

Of course, everyone wants to be “100% Fluent” in a foreign language. Duolingo give you the opportunity to do exactly that, and notifies you whenever you have a percent increase in fluency. It’s a little arcane how the app determines your fluency percentage, but each increase does feel good and creates a sense of fiero. Reaching 100% fluency is the ultimate long-term goal of the app, and users who achieve it feel a great sense of accomplishment and fiero.

Looks nice, but measuring fluency with a percentage is a bit estranho.

To get there, the users play through a web of tiered vocabulary challenges, broken into categories and difficulty. Completing all the challenges in one section lets the user level up to the next level. This is probably the single thing that duo-lingo does best in terms of motivating engagement through fiero. Each challenge must be completed in turn, and unlocks the next one (sometimes multiple) upon completion. The levels get progressively harder, but motivation to finish is increased as the end of the level is neared. Ingeniously, the app also motivates practice on existing skills by “un-completing” previously mastered levels, requiring the user to go back and complete new variations. This is reminiscent of the stars in games like Angry Birds.

Also like Angry Birds, users get infinite attempts to complete a level successfully, though the gameplay loop is not as tight. A level takes at least five minutes to complete.

Completion bars not at full? Better practice.

The last play-like element I want to discuss is the streak counter. This is a feature that simply counts the number of days-in-a-row you’ve used the app to complete at least one lesson. The motivation to keep a streak going is strong, but it does not create fiero since the game does not set specific milestones for the players. Furthermore, when a long streak is broken (for whatever reason) and the counter restarts at zero, this can be very demoralizing. I’d liken it to playing a video game and dying at a boss when you haven’t saved your game in over an hour. This can actually lead to frustration and disengagement. The streak-freeze power-up counteracts this somewhat, but disasters still happen.

Giving Fiero a Power-Up

As we discussed above, there’s plenty of room for improvement in Duolingo when it comes to maximizing fiero. The most successful games let players set many goals, both short and long term, and then achieve them. The simplest and most impactful way for the app to do this would be to both widen and heighten the field of power-ups. By this, I mean adding more variety and including a few “white-whale” type power-ups that users would need to save up for. This would make existing power-ups, such as the double-or-nothing, more meaningful as well.

Players get a thrill of fiero whenever they complete a level, but level-ups are rare in Duolingo. A game shape that features peaks and valleys (alternating easy, difficult, and extremely difficult challenges) help break up monotony, increase satisfaction, and layer more fiero into the experience. Implementing “boss” and “mini-boss” levels to create peaks of challenge throughout a level would not only give users exciting goals to aim for, but also make the app experience more memorable.

Peaks and valleys in game shape

Lastly, I would recommend deemphasizing the streak as the central driving motivator of the game.

This could take one of a few forms: first, remove the streak entirely and replace it with a “daily gift,” a digital treasure chest to open that must be claimed each day. This would encourage users to complete their lessons each day without destroying their motivation when a streak is broken.

An implementation of the “daily reward” mechanic in ‘Game of Thrones Ascent’ by Disruptor Beam

Alternatively, keep the streak, but make it a smaller part of the experience. This could be done by building up other aspects of the app, or by making it into a personal high score that endures even after the streak is broken. Currently, the streak is a snapshot in time, and all “progress” is lost once the streak is broken.

One last strategy might be to place a breadcrumb trail of awards at certain points in the streak. Thus, instead of using the app just to maintain, the player could be constantly working toward something. If the breadcrumbs were useful, it would even motivate users who have to start their streaks over. For instance, if you know you will receive a 15 lingot boost at day 3, that takes a little bit of the sting out of starting from scratch.


Duolingo and Angry Birds share some surprising similarities when it comes to harnessing fiero, but the language learning app could do an even better job of what it already does well. There are many dropped opportunities to let players set goals and achieve them, and the challenge of the “game” sometimes falls flat.

The lessons of this article aren’t just applicable to Duolingo, though. Any app can use fiero to improve user experience and fiero. People don’t just like to play, they like to win. When you design, you should be constantly thinking about how to let users set goals, play, and win.

Since this article was first written, Duolingo has added a new feature to the app called “Duolingo Clubs.” These feature enables you to form groups with your friends and family to encourage one another to learn languages with the app. Apropos to this article is the concept of competition, which is not present in the single-user mode of the app. Duolingo Clubs adds a leaderboard to the app and allows you to compare yourself to other users. There are many opportunities to set and achieve goals (and thus, to experience fiero) here. Since the feature is so new, it’s difficult to say what the effect of it will be on users, or how popular it will become. It will be interesting to see where the design of the app goes from here.

Sam Liberty is co-founder of Extra Ludic, a serious games consultancy based in Boston, MA. He teaches playful design and game criticism and theory at Northeastern University.

Co-Founder of Extra Ludic; Designing and teaching serious games for social change and real-world impact

Co-Founder of Extra Ludic; Designing and teaching serious games for social change and real-world impact