How to play Nine Men's Morris

An ancient board game of placing, sliding and flying. Make rows of three, called mills, to capture the other side's men.

The rules, step by step

The board has three squares inside each other, joined by lines, with 24 points. Each side has nine men. You are red and go first.
In the first stage, you take turns placing a man on any empty point.
Three of your men in a straight line is a "mill". Each time you make one, remove one of the computer's men. You may not remove a man that is part of a mill, unless all of its men are in mills.
When all men are placed, the second stage begins. On your turn, slide one man along a line to a neighbouring empty point.
When a side is down to three men, its men may "fly": they can move to any empty point.
You win when the computer is down to two men, or has no move.

You have men on two corners of the outer square. Placing a third man between them makes a mill, so you take one of the computer's men away.

Block the computer when it has two men in a line with the third point empty.
In the second stage, a man that can slide out of a mill and back in makes a new mill each time.
Choose Easy while you learn. Hint suggests a good move.