Warhammer 40k - Lexicanum:Random page in category
Random page in category is a Special pages tool from the category Redirecting special pages. This tool is basically a specialized version of Random page - only that it limits the pool of potential articles to choose from to a specific Category.
You can also simply click here.
Simply enter the Category you want to find a random article for. If you are not sure how the Category is called just enter the first part of the name and the system will give you an automated list of suggestions.