When I introduce the term base reality to my students, I often begin by saying that it’s similar to having a who, a what and a where. Often, this is how improv is taught to beginners. You use agreement and yes-anding to establish who you are, where you are, and what you’re doing.
As far as I know, the term base reality was coined by either the UCB or one of their teachers to describe what I have often called the situation. It’s more specific than just any old who, what and where, because they need to feel like they belong together. It may be a situation that you have experienced in real life. It may be one that you’ve only seen on TV, in a film or in a book. Perhaps it’s a situation that you’ve never encountered before. But whatever the case, the base reality probably shouldn’t be funny or weird or absurd. If it is, then it’s more than a base reality.
Let’s look at some examples. Let’s say your ‘where’ is a cruise ship. Your ‘who’ is a psychiatrist and a lion tamer. And your ‘what’ is that you are playing Russian roulette. In many improv classes, this would be a fine example of a who, what and where. But it’s not a base reality. It’s too weird to be a base reality.