Accessible Game Interactions: Digital and Analog Inputs

Introduction

Every player interacts with games in their own way. Your game’s controls can influence if they stay, struggle, or leave.

When discussing game controls, inputs are categorized into two groups: digital and analog.

• Digital Inputs are simple button presses, such as keyboard keys and controller buttons
• Analog Inputs have a range of input, such as a trigger press or moving a cursor across the screen

Supporting both digital and analog inputs is key to reaching a wide audience. In this article, we explore the hardware players use, and the audiences that benefit from them. We’ll also include relevant accessibility tags from the Accessible Games Initiative, and design tips to support your players.

Digital Input

Digital input is often easier for many players. This is especially true for those with fine motor disabilities. Approximately 1.71 billion people around the world have musculoskeletal conditions. These conditions impact muscles, bones, joints and connective tissues.

With digital controls, buttons and keys produce binary input, active or inactive. Players use single-button presses to interact. This makes controls less complex.

Digital Input also provides a way to navigate menus without relying on vision, since controls shift focus to the next element. When combined with menu narration, blind and low vision players can hear highlighted options read aloud.

Keyboard

Whether due to disability, injury, or preference, players should be able to play your game with a keyboard exclusively, without needing to rely on mouse or touchscreen inputs.

For the keyboard, all of its keys are digital inputs: simple button presses. Keyboard is a desirable digital input method, as it provides many keys to use or remap. To navigate the game interface, players commonly use these controls adopted from web navigation:

• Move Focus Forward: Tab
• Move Focus Backwards: Shift + Tab
• List Navigation: Arrow Keys or WASD (left-hand friendly)
• Selection: Enter or Spacebar
• Exit Menu or Window: Escape

Some games may opt to use only arrow keys over tab navigation. The benefit to using tab key is that focus moves to the next available element without relying on vision. For instance, if your menu interface was arranged in columns and only used arrow key navigation, blind and low-vision players may miss options since they aren’t referencing the visual layout of the menu.

Controller (Digital Inputs)

Controller is the most common way to play console games. Controller usage is also increasingly being supported in PC games. The digital inputs on a controller include the d-pad, bumpers, and face buttons. The sticks and triggers are analog inputs, which we’ll discuss in the next section.

Alternative Controllers

A game’s digital inputs are much simpler to remap to assistive technologies such as alternative controllers. When discussing alternative controllers, we intend non-default controllers with customizations. Controllers can be flat input devices such as the Xbox Adaptive Controller and PlayStation’s Access Controller. Byowave’s Proteus Controller introduced cube components that allow players to modify controller shape. Controller modularity allows players to adjust their layout in unique ways to suit their needs. For example, with the Xbox Adaptive Controller’s ports, external buttons can set up as foot pedals. Though alternative controllers can support analog inputs, they shouldn’t be required to play your game because they are not widely available or easy to use.

Analog Input

Analog input is the most common way players navigate PC and mobile games. Selections are made by using a mouse or tapping a touchscreen. Some console games may require players to steer a cursor with a controller stick. The range of input that analog controls provide is what defines them, rather than producing binary on-off inputs.

Mouse

Since 1968, people have been using computer mice to interact with computer applications. Mouse captures the motion on a surface and moves the screen’s cursor. Standard mice feature two buttons and occasionally a scroll wheel.

Using a mouse depends on vision. It works by aligning the cursor with what you see on the screen. Players align their cursor with the interface’s elements and confirm their choice by releasing left-click.

It’s a fact that mouse requires precision. Mouse inputs can be more complex with multi-input or path-based gestures, such as click-and-drag features. Dragging an object while holding left-click can be difficult for players with fine motor disabilities. Games that feature either should offer a bypass option or an alternative accessible with digital navigation.

Touchscreen

Touchscreen is most prevalent in mobile games. Advances in game hardware have also led to touchscreen in games on the Nintendo DS, Wii U, and Switch. Touchscreens are becoming increasingly intuitive for young audiences. They provide an engaging way to interact with the game using just your fingertip. When compared to controllers, keyboards, and two-button mice, the primary interaction is a tap.

Mobile games add variation by using holding, repeated tapping, and gestures like swiping or tracing patterns. Touchscreen games may include multi-point gestures. This involves using two fingers, like when pinch-zooming in and out. These complexities applied to touch-based controls create barriers for players with dexterity differences. Avoid relying on them or provide alternative digital controls.

While multi-point gestures can be hard for those with dexterity issues, smartphone screen readers, such as Apple’s VoiceOver, rely on these gestures. They allow users to navigate the touchscreen interface without sight.

Controller (Analog Inputs)

The analog features of the controller are mainly its thumbsticks and triggers. Thumbstick movements depend on x- and y-axis values. Controller triggers commonly have a range of 0-255. Controller hardware frequently innovates new features. Abstract analog controls now include pointer motion capture, gyroscope tilting, and touchpads.

Note: Haptic feedback (controller rumble) and controller speaker audio aren’t player controls. They usually respond to the game’s environment. But, these features still impact how the player uses their controller. If the player likes using their controller on a table or is sensitive to vibrations and sound, the controller features can be distracting. Offer the choice to turn off controller feedback. This allows the player to cut down on distractions.

Eye and Head Trackers

Assistive technologies, like eye and head tracking, work well with games that support mouse input. Eye trackers such as Tobii’s use a camera and near-infrared light to detect eye movement. An algorithm translates the player’s eye movements to a screen cursor, also known as eye gaze. Players can use eye tracking along with other inputs, or they can use gestures. For example, dwell time is how long a player looks at an element to interact with it.

Virtual Reality (VR)

Many consider Virtual Reality (VR) one of the most innovative advances for gaming in recent decades. VR hardware often includes headwear (head-mounted displays) and motion-tracked controllers. The headwear brings the screen up close to the player’s eyes to simulate a wide field of view. It can translate the player’s head movements to the game’s camera for immersion. VR games usually rely on analog controls. This includes pointer motion capture and hand gestures. However, this varies based on the system and app used. If you think of VR as an alternative way to view your game, digital and analog considerations still apply to the interactions and interface within it.

Adjustments for Inputs

In the last sections, we covered the types of hardware players use for digital and analog inputs. In this section, we explore in-game options that further support player inputs.

Remapping

With remapping, players can customize controls to suit their needs and preferences. For instance, a player might remap the left trigger to left bumper if their grip strength is limited. There are currently two Accessible Games Initiative (AGI) tags relevant to remapping:

• “Basic Input Remapping” is earned by offering remapping for all digital controls, for each input that is supported.
• “Full Input Remapping” is earned by games that let you remap all controls, both digital and analog.

For both tags, ‘system functions’ such as the Home or Share buttons are excluded. The controls to operate menus do not have to be remappable either. Menu remapping is often overlooked, but it can help some players. It’s especially helpful when menu navigation uses triggers.

Also, when a player changes a control, it should be reflected across the game’s interface. This helps the player remember their remapping.

Adjustable Sensitivity

All analog controls (triggers, sticks, and mouse) should have sensitivity adjustments. The player can configure how much pressure or movement is required for the input. Reducing sensitivity can prevent accidental trigger pulls. Raising the mouse sensitivity can lower the amount of hand movement needed to move the cursor.

Stick Inversion

The AGI tag “Stick Inversion” is earned when players can invert all analog controls. This includes both the X- and Y-axes on controllers and flight sticks. Stick inversion is interesting because it can be considered generational accessibility. Early shooters and flight simulators flipped the camera’s Y-axis. This change mimics real plane controls and head movements. For example, pulling back makes you look up. Players who began gaming this way often have this perspective ingrained.

No Holds, Repeated Taps, or Combo Inputs

Analog features can be applied to digital controls. This includes button holds, multi-input controls, and quick repeated presses. Each create barriers for players with dexterity differences. Players may not be able to quickly tap, hold, or press a button combination without strain. The AGI tags “Playable Without Button Holds” and “Playable Without Rapid Button Presses” are key for accessible games. Similarly, players may have difficulty with touch or motion control. This is important for the tags “Playable Without Motion Controls” and “Playable Without Touch Controls”.

Toggles

If you can’t avoid these inputs, consider providing an option. One that allows a single digital input to participate in the feature. Even walking and gunfire in games require intermittent button holding. By offering a toggle, or an input to start and then stop the action, strain is reduced for your players.

Designing for Varied Inputs

In this section, we discuss important factors to consider during your game’s design phases. These considerations support both digital and analog inputs.

Simplify Controls

Wherever possible, simplify the inputs required to play your game. The following controls are the simplest for each input:

• Controller: D-pad, A, and B buttons
• Keyboard: Arrow Keys, Enter, and Escape
• Mouse: Left-click

Limiting the amount of necessary controls is easier on player memory. It’s also widely beneficial for players using alternative controllers. Consider the default Xbox Adaptive Controller (XAC). The controller has the buttons: Home, View, Menu, D-pad, A, and B (without additionally purchased extensions). Now think of the Nintendo Entertainment System (NES) controller. Games have long proven the ability to play with limited buttons.

Menu Structure

Menus should have familiar layouts. Consider even menus outside of games, such as streaming services. Selections are arranged in lists or grids. For digital input support, it’s key to show options that can be easily navigated up, down, left, and right. If options are staggered or offset, it may be unclear which direction is best to navigate.

Target Sizing

Consider the text sizes in your game, as they affect menu design. By knowing your game’s text sizes, you can plan padding and spacing better. This maximizes efficiency when arranging your interface.

• AGI tag “Clear Text” specifies that the default minimum of text must be 26 pixels at 1080p.
• The tag “Large Text” outlines text is either by default or scalable to 38 pixels at 1080p.

We offer more insights on text presentation and scaling in our resource “How to Measure Text: Size.”

For analog navigation, whether using a mouse or touch screen, consider your touch targets. These are the clickable areas of the interface’s buttons. Players will struggle if the touch targets are misaligned or too small. The Xbox Accessibility Guidelines feature “Guidelines for Mobile Inputs” that recommend:

• A 15×15 millimeter touch target for phones
• A 24×24 millimeters touch target for tablets

When considering players using eye trackers, targets may need to be even larger.

Distinguishable Focus

When digitally navigating, players need a visual indication of which option is highlighted. This is accomplished with a variety of effects. A classic technique is adding a box border around the highlighted option. Designers can also be creative by using shapes, shading, or size to emphasize it.

The best focus indications take inspiration from the Web Content Accessibility Guidelines (WCAG) success criterion “Focus Appearance”:

• Ensure the color contrast is over 3:1 against the background and non-highlighted elements.
• Don’t overlap on top of the game’s text.
• Don’t rely on color change alone.
• If a border is used, line width isn’t too thin, with a thickness of 3-5 pixels at 1080p.

For analog navigation, the cursor may not be enough to understand which option is highlighted. For touchscreen, without a cursor, this can be less clear. Its helpful to provide a focus effect when an option is hovered or after being tapped.

Players can also benefit from sound effects such as soft clicks when focus shifts. They are supportive auditory cues, providing subtle feedback to the player’s inputs. It can also aid players navigating menus by sound. Ultimately, menu narration is the primary audio players with low or no vision rely on to navigate menus.

Focus Order

Consider the focus order or the order options are navigated through your interface. If key features like settings, new games, and chatting are last in the selection order, it can make it hard for players to reach them easily. Show the most important options first to make navigation easier. You can also reduce cognitive load by ensuring that not too many options are available on a single page.

Note: For English-based games, focus order is typically top to bottom and left to right. Match the focus order to the reading order of your game’s main language.

Looping Focus

A hot topic in the subject of focus order is whether the menu should loop back to the first option after the last one is highlighted. Looping lets the player move ahead, knowing they’ll return to a skipped option. It also mirrors keyboard navigating webpages. Not looping may be more beneficial to players using menu narration. The end of page options is more clear since focus lands on the last option instead of looping back to the first. This is an example of conflicting accessibility. A feature may be easier for one player’s access but harder for another. For games with advanced settings, perhaps offer a choice.

No Keyboard Traps

When designing menu navigation, it’s important to consider web principles. One key principle is the WCAG success criterion: “No Keyboard Traps.” Keyboard traps are moments the focus becomes stuck, perhaps in a unique window, where the user cannot escape with their keyboard. These hindrances can also occur for controllers and cause digital navigation inaccessibility. These situations can frustrate players. They may need to reboot and avoid the menu, or involve other hardware to keep playing.

No Mouse Traps

Now apply the concept of Keyboard Traps to players using a mouse to navigate. If they encounter pop-up windows that cannot be closed with left-click, this becomes a ‘mouse trap.’ The mouse alone can’t be used to escape. These situations also call for rebooting or other hardware to continue.

Conclusion

Designing for both digital and analog inputs isn’t a feature; it’s a foundation. When players can use their preferred input method, your game is easier to access. It becomes more comfortable to their experience.

The decisions you make surrounding inputs matter. They can create a frustrating barrier or a smooth, playable experience. Remapping, toggles, menu layout, and sizing factor into your game’s playability. By giving your players control over how they operate your game, it becomes accessible to a wide audience.