This domain exists only as a metric problem. The problem is inspired by the multitude of computer games that involve managing resources, accumulating raw resources and slowly combining them into more and more advanced processing plants and other structures to achieve more sophisticated objectives. The problem was proposed by Patrik Haslum. An interesting difficulty that the problem presents is that it is a problem that involves constructing new objects out of resources. This is not easily represented in PDDL2.1. In fact, the only way to capture the domain in PDDL2.1 is to name the objects that could be constructed and to give them an attribute indicating whether or not they have actually been constructed. This leads to a very cumbersome encoding and, moreover, represents a particular problem for planners that ground actions prior to planning, since a multitude of potential objects must be considered in the process, leading to a huge collection of actions. Many of these actions are uninterestingly different, since the specific choice of names for objects that are created in solving an instance is clearly irrelevant, but each alternative is constructed and considered in the planning process.