Chinese puzzle
1. A puzzle game consisting of intricate and complex pieces that fit together in a specific manner, especially of multiple boxes that fit inside one another. My uncle gave me this Chinese puzzle for Christmas, and I still haven't been able to solve it!
2. Any problem, question, or situation that is especially complex or difficult to understand. Dealing with growing income inequality is truly a Chinese puzzle for lawmakers today. I can't understand a thing about how this engine works, it's like a dang Chinese puzzle!