Shih is a simple game. Here are the rules.
You get two Movement Points (MP) per turn, which you can spend these ways:
Step (1MP): Click on one of your pieces and then click on an unoccupied adjacent space with no walls in between.
Spin (1MP): Click on an unoccupied space adjacent to one of your pieces, provided the wall on the space your piece occupies is not in the way. Then click again to the right of the first click to rotate clockwise, or to the left to rotate counter-clockwise. If this encloses enemy pieces properly, you will capture them. A shift-click cancels this.
Power Spin (2MP): You get two Power Spins (PS) per game. They work just like spins, but use shift-clicks instead of clicks. Also, if you capture any pieces with one, you must surrender an equal number, but you do get to choose which. A regular click cancels this.
One final note: The outside of the board always counts as a wall.