Using Gestures in Mobile Game Design
The thoughts and opinions expressed are those of the writer and not Gamasutra or its parent company.
Mobile gaming today often means gaming on your mobile phone or tablet. Because so many (if not all) of these devices are touch screens, one way you can make your game more interesting and engaging is to make innovative use of gestures. But how exactly do you do that? How do you do it well in this crazy, high-interruption world? And where do you begin?
Mobile gaming often implies a very specific context that users are playing in:
- varying lengths of play sessions, often very short (depending on how long someone takes to make your cappuccino or the length of a commercial break)
- lots of interruptions
- usually a touch screen that's capable of multi-touch
- higher and higher resolution screens, but for phones still small enough to fit in one hand (for tablets, to fit nicely in your lap)
- even varying lighting and sound situations!
For the purpose of this article, we're going to assume people are playing on mobile phones and tablets in these kinds of situations. There are some gestural games, such as Infinity Blade, that you might argue a person sits down solely to play that game and focus all their attention on it. That might be true, but I'm not talking about those kind of games. ;-] Raise your hand if you're NOT addicted to multi-tasking? No one? OK, let's move on.
So what kinds of gestures will actually result in a great addition to your game's user experience? And which will just be a waste of development dollars? Keep reading for some tips on figuring that out.
What exactly is a Gesture?
A gesture on its most basic level is a movement of a finger, hand, or other part of the body to express an idea, desire, or other human thought. Initially, some devices could only process the touch of one digit at a time, but multi-touch devices can perceive both gestures made by one finger and those made by more than one at the same time. (Android and iOS devices are almost always multi-touch.)
Exactly how a specific gesture is named and conceived of varies between platforms (iOS vs Android vs Windows Phone vs Palm vs Take-Your-Pick). Luke Wroblewski has an excellent Touch Gesture Reference Guide on his site that illustrates, documents, and explains core gestures, as well as how they differ slightly across platforms.
Some examples of common multi-touch gestures and actions you might use include:
- Pinch to zoom in, spread to zoom out
- Basic dragging in order to move, adjust, scroll, and position
- Flick to jump to the next screen or scroll extra fast
- Tap and hold to open an item or context menu
- Multi-finger drag often scrolls faster!
- Multi-finger rotate can rotate objects in 2D or move a 3D camera
Having a list of gestures that your platform and tools can support might help you think of ideas for where in your game they might feel good.
Things to consider: Timing
How long a gesture lasts is just as important as how many fingers are involved. How long is the difference between a drag and a flick? How long does a tap last before it becomes a tap and hold? How long between taps makes a double tap? Your tools may have standards, or you may need to decide for yourself. If you decide for yourself, be sure to conduct usability testing to verify your choices.
Things to consider: How is the device held?
If you've every tried to use your maps app to navigate around an unfamiliar city while carrying your luggage, you may have encountered how not all gestures work great all the time. For example, when you have only one hand, pinching to zoom in becomes very difficult, and zooming out becomes nearly impossible. Many apps include a secondary double tap gesture to zoom in, so that there is also a gesture for one-handed use. But unfortunately once you scroll in, you're stuck, because there is no one-handed zoom-out gesture. (Unless someone wants to enlighten me in the comments!)
Of course, you can just pick a way for a device to be held and hope your users conform. But before you do that, I urge you to consider: how many different ways can your device be held while playing? Phones can be held in left hands, right hands, and both hands, both vertically and horizontally. Big hands can reach a lot farther than small hands, lefties will find somethings easier than righties. How much you consider this and design for it directly impacts how easily people can play your game. And that impacts how often they will play it. Translation: DAU. Not to mention that if a game is easy to play when I want to play it, I'm going to like it a lot more.
Of course, ideally your game would be perfectly suited to every play situation, but let's be real here. Time and money are finite, and so you may have to make some choices. Some game concepts simply require two hands for the mechanic to work. At Radiant Wolf when we were designing our latest game Alien Outcasts, we wanted to make a sim that could be enjoyed for very brief sessions in many diverse play environments. We choose a vertical orientation and always assumed one-handed play. This way Alien Outcasts could be played in line for your coffee, under the table in your meeting, while you're feeding a baby.... You get the idea. This was inspired by games like Tiny Tower.
If you've found an exciting way to use a multi-touch or two-handed gesture, consider adding a secondary gesture or dedicated button for when your player is also eating a sandwich. ;-]
Things to consider: Intuitiveness & Discoverability
Touch interfaces have sometimes been called "natural" interfaces. Others have argued that there's nothing particularly natural about interacting with light under a pane of glass. In practice, it seems there are just as many hard to use gestural interfaces as there are people out-of-their-minds excited to use them. How natural gestures are depends on your unique game, genre, platform, and more. Pinching to zoom is an example of a particularly intuitive gesture, but many other gestures are hard to guess.
When adding gestures to your game, here are some questions to ask yourself:
- How would a user every know this gesture is here? How will they learn it? Does it work as part of a tutorial or in context tip?
- If there's no tip or tutorial, how likely is a user to discover this gesture? Will they attempt it on their own? This is not a question where it pays to be an optimist. When in doubt, test it out!
- How common is a use of this gesture in this type of situation? Is it a convention?
- Is gameplay still fun if they don't figure the gesture out? Is it still possible?!?
In Alien Outcasts, one approach we took was to often make gestures optional, enhanced interactions. We also tried to hint at them whenever possible. So while you can swipe between planetary systems or alien floors, or drag to collect coins from all your planets at once, you can also simply tap on buttons or coins to achieve that goal as well. So, don't be afraid to double encode. Even if there's a gesture, a button or hint may still be important to guide users along. Or they may simply prefer it.
Things to Consider: Don't get addicted.
All right. We get it. Gestures are super cool. So cool you want to just fill your game with them, so it will shine like the glowing jewel of innovation and creativity that it is. Or will it?
Sometimes gestures add things, and sometimes they don't. Tiny Wings is an excellent example of an elegant, creative, ingenious game using a basic gesture in a simple but wonderful way. To tap or not to tap is the only question, and it's a fun and interesting one that can be immediately grasped and experimented with. (Although one could argue this gesture is more precisely a tap-and-hold...)
I'm not going to trash any games here, but we've all run into ones where the gesture just didn't work. You tried to make it, and nothing happened. Or you found out after two months that it was there all along, and you had no idea. Or you were overwhelmed trying to remember all of the ones you needed to navigate the interface!
So be bold, but also be careful. The world of gestural interfaces is still very new, and it's kind of like the real world in that there are some awesome places, and some not-so-nice ones.
Things to Consider: Do get inspired!
Get on that App Store and find some games that use gestures well. Analyze. Be critical. What is it about it that works so well? Find games where the gestures are awkward and distracting. What went wrong? Develop your own unique perspective on how you like to see gestures in games. And don't forget to test and ask others for their opinions, too.
Some examples? Games like Fruit Ninja and Infinity Blade spring to mind as mobile games with core gestural mechanics. Anyone remember Black and White 2? Sure it's a non-mobile PC game, but it had gestures for miracles.... However, they never really worked that well for me. Maybe it was the mouse, maybe technology just wasn't ready.
Here are a few more examples of gestures in games. Go out and make your own list of what does (and does not!) inspire you!
Swiping in Temple Run
With just a few swipes in a few directions, Temple Run hits a home run in terms of using gestures immersively to create a simple but extremely engaging user experience.
Rotation in TanZen
This relaxing little puzzle had quite elegant rotation and positioning interactions.
All Sorts of Gestures in Dumb Ways to Die
Every little mini-game in Dumb Ways to Die seems to have a different gesture associated with it: flicking, tapping, drawing, sliding, blowing, tilting. It's a fun nose-dive into tons of examples of simple but fun gestures.
These are just some that I liked. There tons of games out there making innovative use of gestures every day.
What are the best examples you've seen? Let's hear it in the comments.
If you'd like to find out more, here's some link love on Gestural Interface Design:
- Sci-fi Interaction Interfaces! YES! on Smashing Magazine
- Don Norman and Jakob Nielsen argue that gestural interfaces are a step backward
- Designing Gestural Interfaces book, by Dan Saffer
- Nice slide deck on the usability of gestural interfaces