This game can be played in some different rule sets. Therefore, you can do some adjustments before starting a game here. The rules for the most important variants are described here.
You can move a piece by clicking it and then clicking the field it should go to. In case of moves that consist of multiple steps, click on the destination of the last one of them.
Your game will be stored and identified by the URL. So after starting a game, you can always come back to it by going to the URL you got redirected to on game start.
The AI opponent
When playing against the computer, its strength is determined mainly by the time you allow it to think. You can set this to a value between 3 and 20 seconds when starting a game.
After calculating a move, the computer will remember it for future games, so by time it will have fast responses in more situations.