Techniques for virtual area generation and manipulation are described herein. The described techniques may be used, for example, for virtual areas in electronically presented content items, such as video games and other media items. In some examples, one or more interfaces may be provided that allow content developers to provide and specify a set of rules associated with the virtual area. The set of rules may include, for example, terrain rules, object rules, and other rules associated with other aspects of the virtual area. The terrain rules may include rules for generating, distributing, and/or manipulating different types of terrain, such as such as flat and/or buildable space, mountains, valleys, berms, rivers, lakes, oceans, deserts, forests, and many others. The object rules may include rules for generating, distributing, and/or manipulating different types of objects, such as trees, bushes, rocks, snow, grass, fish, birds, animals, people, vehicles, buildings, and others.