The advance of the theory of contingent claim pricing has made it possible to model and analyze very complex financial claims. When the value of the firm can be represented as a contingent claim, then the firm's optimal financial policy can be determined with only a slight modification in standard solution techniques for contingent claims. In this paper, stochastic control theory is used to determine a dynamic investment policy for the value-maximizing firm. The value of future, stochastic economic rents (i.e., the net present value of the firm), and the firm's optimal investment policy must reflect a rational reaction on behalf of its competitors. A computationally efficient methodology is presented for solving the simultaneous investment-valuation problem for an n-firm game.