Maybe you didn’t want your kid to play with toy guns or toy soldiers, so you gave him some wholesome, creative Lego bricks. Which works until he uses the interlocking plastic pieces to make a tank.

“So, this is the Second Battle of El-Alamein near the Kidney Ridge area in North Africa,” said 10-year-old Phineas Versteeg of his 10,000-piece World War II diorama display showing British tanks and ...