This survey presents algorithms for the automatic generation of content for virtual worlds buildings in particular for games. After a definition of the term procedural content generation living beings and stories are introduced in detail. In our discussion road networks the algorithms to generate realistic objects such as landscapes and vegetation virtual worlds; procedural content generation; multimedia content creation; serious games we emphasize a good compromise between the realism of the objects and the performance of the algorithms. The survey also assesses each generated object type in terms of its applicability in games and simulations of virtual worlds.