FUNDAMENTALS OF GAME DESIGN, SECOND EDITION
Accessibility Issues
Although it took them a while to get around to it, Microsoft now leads the world in making their operating system and office products available to people with disabilities of various kinds. The game industry, regrettably, remains far behind. Its origins in arcade and twitch gaming have produced an unquestioned assumption that games are only for people with excellent eyesight and good hand-eye coordination. But many people who don't possess these abilities also would like to play games, and you should consider ways to make your game more accessible to them.
Physical impairments fall into three general categories: visual, auditory, and mobility.
Vision impairments fall into several subcategories that require slightly different adjustments. In any case, you should provide audio cues to go with visual cues.
Very few events in a video game should be silent ones. When a player selects a unit, have the unit acknowledge its selection with a sound. When the player gives an order, presses a button, or chooses a menu item, be sure to indicate it with an audible cue. These cues can be quite subtle; there's no need to ring loud bells, but make sure the player hears something, even if only a little tick sound.
You can help some players with cataracts and similar conditions by giving them brighter, more high-contrast images. Most likely, these players will already have turned up the brightness and contrast on their monitors, but your game can further augment this by letting players adjust the contrast in your game, assuming that you have a display engine powerful enough to support this feature. Also, make the textures in your game available for modification. Vision-impaired players can then edit your textures to meet their own needs.
Be sure to include enough contrast in your user interface elements as well as your game world. Don't try to be cool by using black-on-black or gray-on-gray menus or indicators.
Increasing brightness or contrast alone is not enough to help people with certain low vision conditions such as macular degeneration. If you really want to make a game that vision-impaired players can see well, you will need to do further research. Institutions such as The LightHouse and the Wilmer Eye Institute at Johns Hopkins University (both in the USA) may be able to direct you to additional resources.
