Extension:Random In Category

The Random In Category extension allows you to direct the user to a random page in a specified category.

Usage
Very similarly to Special:Random, you can specify a category name as a parameter to the page. Thus, "Special:RandomInCategory/Foo" or "Special:RandomPageInCategory/Foo" (MW ≥ MW 1.22) will get you a page from the "Foo" category.

Comparison to Core
In MediaWiki 1.22, a Special:RandomInCategory feature was added to core. The core version gives much more biased results than this extension (However, it has much less performance overhead). Versions of this extension for MediaWiki 1.22 and greater change the name that this extension provides from "Special:RandomInCategory" to Special:RandomPageInCategory to prevent conflict with the core feature.