Blocking is the general term for any behavior that refuses, deflects, or undermines the offers in a scene. It is the family name — negation, steering, bulldozing, hesitation, and the other principle-shadows are its species.
The most visible form is verbal denial: "No, we're not in a hospital." But blocking operates at every level. You can block emotionally — accepting the words, ignoring the feeling ("You seem upset" / "I'm fine, let's move on"). You can block physically — turning away, breaking eye contact, retreating from your partner. You can block through inaction — refusing to add, forcing your partner to carry the scene alone. And you can block your own offers before they leave your mouth — having an impulse, judging it, suppressing it.
Two roots, not one. Fear produces blocking — fear of the unknown, fear of vulnerability, fear of not being funny. But so does dominance. Johnstone observed that high-status players block to maintain control: the offer is refused not because it is scary but because accepting it would mean ceding authority. The question "am I serving the scene or my comfort?" should be expanded: am I protecting myself from uncertainty, or am I protecting my status?
A critical distinction: the word "blocking" operates at two levels that must not be confused. A character can refuse another character's request — that is drama, not blocking. Blocking in the improv sense is when the performer refuses the other performer's creative offer. TJ and Dave's characters say no to each other constantly; TJ and Dave the improvisers never block. Character-level denial can be the game of the scene. Performer-level denial kills it.
Johnstone catalogued an entire family of avoidance behaviors beyond simple denial — wimping (accepting without adding), cancelling (making an offer and immediately retracting it), bridging (delaying action with preparation), hedging (making offers so vague they can't fail), pimping (forcing your partner to do the creative work). These are blocking's cousins. The taxonomy matters because each requires a different correction.
Napier offers an important counter-frame: the fear of blocking can itself become a trap. Improvisers so terrified of saying no that they robotically "yes, and" everything produce tepid, compliant, lifeless scenes. Mechanical agreement without personal investment is its own form of scene-death. The principle is not "never deny" — it is "serve the scene with your full creative self."
Understanding blocking matters not to create shame but to build recognition speed. Every improviser blocks. The goal is not to eliminate the impulse but to notice it faster and choose the scene over the self.