Effects are good, but side-effects are bad. Well, ok. What's the difference? What do we mean when we talk about effects, and what are the rules of the game? In this beginner/intermediate talk we will talk about some familiar effects like `Option` and `List`, build up some more interesting effects of our own, and talk about how to think about programs as "computations" that are values we can manipulate like any other kind of data. Along the way we will do some equational reasoning and talk about applicative and traversable functors, monads, and other intimidating words.