So, there must be something special about the game itself. It's a deceptively simple game of strategy, easier to learn than chess, and appropriate for almost all age of players. Even as kids, we had a great time competing at Merrills, also known by its English name Nine Men's Morris, even if the lengthy tournaments sometimes ended in tearful dejection (mostly the fault of my poor sportsmanship). Seek out the rules and you'll see how straightforward the game can be.
All it takes is a board and eighteen uniform pieces of two different shades (dark and light colored pebbles work well). Check out the stone below for the layout of the game board. Challenge!