How to Set Up Automated Accessibility Checks for Games

Accessibility is not a feature you ship once. It is a set of invariants that must hold true across every update, every patch, every new piece of content. A colorblind mode that worked in version 1.0 can silently break in version 1.3 when a designer adds a new UI element that relies on red-green distinction. A font size setting that respected the player’s choice everywhere can fail in a new menu screen where someone hard-coded the size. Automated checks catch these regressions the same way automated tests catch logic bugs: consistently, tirelessly, and before a player has to file a report.

Building Your Accessibility Test Matrix

Before you can automate anything, you need to know what you are checking. An accessibility test matrix is a table that lists every accessibility feature your game supports, the measurable criteria for each, and the pass/fail threshold. Start with the features that affect the most players and are the most automatable.

Colorblind modes should be verified for all three types: protanopia (red-blind), deuteranopia (green-blind), and tritanopia (blue-blind). The criterion is that no information is conveyed by color alone — every color-coded indicator must also use shape, pattern, or text. Font size minimums should be checked against a threshold (typically 18px at 1080p, or 24px for critical gameplay text). Subtitle rendering requires background contrast (a semi-transparent backdrop or outline), speaker identification, and a minimum size. Control remapping requires that every gameplay action can be rebound and that no two actions are locked to the same input.

Write the matrix as a YAML or JSON file that your test scripts consume. This makes it easy to update thresholds without modifying code and lets non-engineers (designers, accessibility consultants) review and contribute to the criteria.

Automated Colorblind Checks

Colorblind verification starts with screenshots. Capture a screenshot of every major game screen — main menu, HUD during gameplay, inventory, map, dialogue, settings — and run them through a colorblind simulation filter. Libraries like Pillow (Python) or ImageMagick can apply the Brettel/Viénot/Mollon color transformation matrices to simulate each type of color vision deficiency.

# colorblind_check.py — simulate CVD and check contrast
import numpy as np
from PIL import Image

# Protanopia simulation matrix (Brettel 1997)
PROTAN_MATRIX = np.array([
    [0.152286, 1.052583, -0.204868],
    [0.114503, 0.786281,  0.099216],
    [-0.003882, -0.048116, 1.051998]
])

def simulate_cvd(image_path, matrix):
    img = Image.open(image_path).convert("RGB")
    pixels = np.array(img, dtype=np.float64) / 255.0
    simulated = np.clip(pixels @ matrix.T, 0, 1)
    return Image.fromarray((simulated * 255).astype(np.uint8))

def check_contrast_ratio(color_a, color_b):
    # WCAG 2.1 relative luminance formula
    def luminance(rgb):
        r, g, b = [x / 12.92 if x <= 0.04045
                    else ((x + 0.055) / 1.055) ** 2.4
                    for x in rgb]
        return 0.2126 * r + 0.7152 * g + 0.0722 * b

    l1 = luminance(color_a) + 0.05
    l2 = luminance(color_b) + 0.05
    return max(l1, l2) / min(l1, l2)

After simulating color vision deficiency, compare adjacent UI elements that carry distinct meanings (health bar vs. mana bar, friendly vs. enemy markers). If the contrast ratio between them falls below 3:1 under simulation, the check fails. This does not replace a human evaluator — only a human can judge whether the shape and pattern alternatives are sufficient — but it catches the most obvious regressions automatically.

Font Size and Subtitle Validation

Font size checking can be surprisingly simple if your UI is data-driven. If your game defines font sizes in configuration files, theme assets, or style sheets, write a script that parses these definitions and verifies every value against your minimum threshold. For engines like Unity with TextMeshPro, you can write an Editor script that scans every TMP component in every scene and prefab, checking that the font size (accounting for the canvas scaler) meets the minimum.

Subtitle validation goes further. Capture screenshots of every dialogue line with subtitles enabled and verify three things: that a subtitle is present (OCR or by checking the subtitle overlay rendering), that the subtitle has a contrasting background (compare the text color to the pixels directly behind it), and that the text height in pixels meets the minimum for the screen resolution. If your game supports subtitle scaling, test at both the minimum and maximum scaling settings to ensure neither breaks the layout.

The subtitle check can also verify speaker identification. If your subtitle system tags each line with a speaker name and color, the automated check can verify that the speaker name is present and that the speaker color meets contrast requirements against the subtitle background. Missing speaker names are one of the most common accessibility complaints for narrative games.

Control Remapping Verification

Control remapping checks are purely data-driven. Your game’s input map defines which actions exist and which inputs they are bound to. An automated check should verify that every action in the map can be rebound (no hard-coded bindings), that no two actions in the same context share the same default binding, and that every action is reachable with both keyboard/mouse and controller. If your game supports one-handed play or switch-accessible input, verify those configurations as well.

The check should also verify that the remapping UI itself is accessible: can a player navigate the remapping screen and change bindings using only a controller? Using only a keyboard? If the remapping screen requires a mouse click to open the rebind dialog, a controller-only player cannot remap their controls, which defeats the purpose entirely.

Integrating with CI

Run accessibility checks as a CI step after your build completes but before artifacts are published. The checks should produce a structured report (JSON or JUnit XML) listing each criterion, whether it passed, and the measured value. Display the report on your build dashboard alongside test results and binary size.

Not every accessibility failure should block the build. Define severity levels: critical failures (text below readable size, completely broken colorblind mode) block the build; warnings (contrast ratio close to threshold, subtitle background slightly transparent) are reported but do not block. This prevents the team from ignoring accessibility checks due to false positives while still catching genuine regressions.

“Accessibility is a spectrum, not a checkbox. Automated checks do not make your game accessible. They make sure it stays as accessible as it was yesterday. The hard work of designing accessible experiences requires human thought and player feedback.”

Beyond Automation: The Human Testing Layer

Some accessibility criteria resist automation entirely. Is the audio description sufficient for a blind player to understand the game state? Is the haptic feedback pattern for a critical hit distinguishable from the pattern for taking damage? Does the high-contrast mode make the game playable for a low-vision user, or does it strip away so much visual information that the game becomes confusing? These questions require human testers, ideally players with the disabilities you are designing for.

Automated checks free human testers from verifying the measurable, repeatable criteria so they can spend their time on the subjective, nuanced evaluations that only humans can perform. A well-designed accessibility testing strategy uses both: machines handle the regressions, humans handle the experience. Together, they produce a game that more players can enjoy.

Related Issues

For testing your game with screen readers and other assistive technology, see how to test your game for screen reader accessibility. For integrating accessibility checks into a broader CI pipeline, read how to build automated smoke tests for game builds.

Every automated accessibility check you add is a promise to your players that the feature they depend on will not silently disappear in the next patch.