Detect whether browser has keyboard/arrow keys in web page

Question

I have a full-screen game in HTML+JavaScript, which uses the arrow keys as primary controls. This cannot be used on keyboardless Android devices (I haven\'t tested on iOS),

Answer 1

Use feature detection with Modernizr: http://www.modernizr.com/docs/#touch

While this is not a reliable way to check if the user has a keyboard it is definitely reliable to see if the browser is capable of touch.