This paper presents the design of a 3D missile guidance law based on a second order sliding mode control technique employing an adaptive tuning law and a fuzzy gain scheduling. At the outset, the super-twisting sliding mode guidance law is obtained to overcome the chattering phenomenon. Then, without the knowledge about the bounds of disturbances, an adaptive law is used to determine the control gains. The results are enhanced using a fuzzy module that provides the controller parameters according to a set of linguistic rules. Finally, a comparative set of simulation results are given. To verify the performance and effectiveness of the proposed guidance law, we compare the performances of the traditional sliding mode (SM) guidance law, the traditional super-twisting sliding mode (STWSM) guidance law, the adaptive super-twisting sliding mode (ASTWSM) guidance law and the adaptive fuzzy super-twisting, sliding mode (AFSTWSM) guidance law. The simulation scenarios consider fundamental target movements. The results demonstrate that the proposed adaptive guidance laws display better performance in terms of miss distance, intercept time, and final closing velocity compared the alternatives considered in this study.