Yes there is. What should i do?
You can add the exe of warband and put "run on dedicated graphics (nvidia graphics).
Or just put in global configuration that you want nvidia graphics, and all will go by the nvidia (the desktop still will go by the intel). But that option it's not recommended for the battery life. This system is pretty good for preserving the battery, will not use great graphic card if you don't need it, so the power supply don't gonna run over that fast.
As I said, in the moment you are running the game on your nvidia, you should try different configurations in the graphic options, and try what it's better for your computer. By the way, the last graphics on nvidia are not compatible with optimus system. You should download the graphics from your supplier page (asus in your case). This graphics will be old, but they will run better with your hybryd computer.