A new form of board game blossomed in the 1990s, combining simple rules and strategic complexity. These “Eurogames” (which are most popular in Germany) put a premium on interacting with other players, long-range planning and managing limited pools of resources. Unlike traditional games like Monopoly, they de-emphasize direct conflict between players; capturing enemy pieces or eliminating opponents are rare occurrences. And they’re ripe for the same kind of deep study that people have given to chess, backgammon and poker.

The...