A Monte Carlo (MC) simulation is one that uses a random number generator in some capacity, and they're sometimes colloquially referred to as "throwing darts". They're used in a wide array of different contexts, but very commonly in physics (which is where I learned of their usefulness). They're great for estimating solutions to very complicated problems that often involve draws from different probability distributions, addressing optimizations which can't be solved analytically, and estimating the sensitivity of a complicated function to varying the input parameters.

I'm writing this blog post to convince you to start playing with your own darts to quickly solve problems and answer common questions. This approach wouldn't have made as much sense 10-20 years ago, but since computing power is so fast and cheap nowadays, you can often use simple MC simulations to get approximate solutions much more quickly than if you had tried to rigorously solve the problem.