Improv, in this context, is theatre that is created on the fly. There are no "rules" of improv, other than perhaps it's not scripted or rehearsed in any real way. Of course this can apply to any creative act that is improvised, be it music or dance and so on. But for this piece, I'm going to focus on my specialty, improvised theatre.
There's certainly guidance that helps newer performers. The classic "Yes, And" is a good example. With a little experience, most improvisers can see that this isn't meant to be literal advice to blindly say "Yes" to everything but rather good beginner guidance to prevent nervous improvisers from shutting down their partners' ideas. But good improv and healthy boundaries have plenty of room for "No". There are also structures and forms that help shape a scene or a show, like a short-form game or a Harold. But improv can and does happily live outside of those structures.
We can also practice theatre skills as improvisers. Object work, characters, stage blocking, voice... the list is endless. Developing your skills as a performer allows you to put more tools in the toolbox, so you can pull out the ones you want when the moment calls for it.
Rehearsing, practising, developing... these are things we do as improvisers that allow us to bring order to an inherently unpredictable craft. Whether it's a show structure or a specific skill, improvisers put in a lot of work offstage that can pay off onstage. Building a performer's instincts through practice and rehearsal are surely a good thing.
But what happens when we rely too much on structure? What happens when we repeatedly or mindlessly fall back on trained habits? Or we get stuck in a pit of overthinking things and suffer from analysis paralysis? Our performances can become stale, robotic, or repetitive. They might feel uninspired to the performer or, worse, look uninspired to the audience. It's a pitfall for any player.
The opposite can also be a trap. What happens when there is no structure? What happens when a player jumps from non sequitur to non sequitur? When no craft is present and pure intuition is deployed? Random lines of dialogue with no awareness of context or the game being played can leave the other players and the audience feeling adrift or confused. The scene can feel totally aimless and self-indulgent.
Too much order and the scene feels flat. Too much chaos and the scene feels meaningless. The sweet spot is right down the middle. There's a line that exists between the conscious choices of control and the unconscious instincts of impulse. Our challenge as improvisers is to find that line, the boundary between order and chaos, and ride it. The scene controls you AND you control the scene, the perfect marriage of craft and spontaneity.
It's just one of the many paradoxes an improviser faces when performing. Learning to resolve it, to thread the needle between these opposing yet complementary forces, is the goal.