Blender materials for the game engine redirect Tex-face options over to blenders material panel. This allows you to set multiple materials on an object and multiple textures to that material.
Sixteen materials can be assigned to one mesh. Three textures are available for each material assigned to the mesh.
Regular UV-mapped models will still use the old game engine method.If:
1). The mesh has no material actively assigned to it.
2). The material on the object is set with the option Tex-face.