This chapter aims at developing a unified FOV-limited guidance framework from which a variety of 2D and 3D cooperative guidance laws can be derived. First, the unified method for 2D guidance is established by augmenting an arbitrary baseline guidance law with a biased command. To mitigate the effect on the baseline guidance law, this biased command is designed in the admissible range that respects the FOV limit and only takes effect when the lead angle approaches the FOV bound. Then, the unified method for 3D guidance with coupling nonlinearity is developed by exploiting the geometric relation among space angles. With the proposed method, various illustrative guidance laws including cooperative guidance laws are derived to demonstrate the significance of the unified framework. Finally, numerical simulations with comparative study are conducted to support the analytical findings and show the superiority of the proposed method.