1 Jamie: I’ve also invented a new board game.
2 Adam: Cool! How do you play?
3 Jamie: You’re trying to take over the world, and to do it you need to solve a bunch of differential equations.
4 Adam: Neat. What’s it called?
4 Jamie: Calculated Risk.

Risk is a classic^[1] board war game, released in 1957. Most of you have probably played it at some point. As war games go, it's relatively tractable and mainstream, involving a lot of dice rolling and abstraction of "armies" moving across a stylised map of the globe, rather than looking up tables of tank movement rates per model versus terrain and weather conditions on the Russian front. So it remains popular to this day, and like its other cash cows Hasbro has marketed the hell out of it with numerous licensed versions in recent years.

[1] "Classic" in the context of board games usually means "invented before people understood how to make games that are actually fun to play". Although given some of the other old games still floating around, Risk is not the worst offender by far.