We posit that experimentation is a central element of the creative process. The question then becomes how can we support experimentation in creative tasks? We take inspiration from the success of computer aided design (CAD) environments that enable designers to construct, evaluate and revise models of engineering systems. Design of game-playing software agents is another creative task. By analogy, we present a CAD-like environment that enables designers to construct, evaluate and revise models of game-playing agents. However, unlike engineering systems, intelligent agents may learn from experience. In particular, intelligent agents may use meta-reasoning over their own models to redesign themselves. Thus, we envision a CAD-like environment in which the human designer and the intelligent software agent cooperate to perform interactive meta-reasoning to redesign the agent. In this article, we describe three elements of this vision: (2) an agent modeling language called TMKL2, (2) an interactive environment called GAIA for experimenting with the models of game-playing software agents, and (3) GAIA’s module called REM that performs meta-reasoning for self-adaptation in game-playing software agents. We illustrate these concepts for the task of design of software agents that play variants of Freeciv, a turn-based strategy game.