Blocking

One of the most fundamental concepts in improvisation pedagogy, blocking refers to the act of refusing or negating a scene partner's offer, typically through responses such as 'yes, but' or 'no,' which prevent the collaborative narrative from advancing. It stands in direct contrast to acceptance ('yes, and'), which is generative and builds productively on what a partner introduces. Blocking can be overt, as when a performer flatly contradicts an established reality ('That's not a dog, it's a cat'), or subtle, as when a performer redirects focus away from the partner's contribution without acknowledging it. Keith Johnstone identified fear of failure, humiliation, and rejection as root causes: performers block because saying yes feels risky, and negation offers the illusion of control. In applied improvisation settings, facilitators use blocking and accepting as contrasting dynamics to illustrate how 'yes, but' thinking stifles collaboration and creative problem-solving in workplaces, while 'yes, and' opens generative possibilities. In theatrical improv, chronic blocking stalls scenes, burdens partners with the work of re-establishing reality, and erodes group trust. Recognizing one's own blocking impulses is often the first step in developing spontaneity, as performers learn to notice when fear is constraining their creative instincts rather than protecting them.