The total processing capacity available to participants in a shared interaction at any given moment. Bandwidth is finite, shared, and consumed by every signal sent and received.
In improv, bandwidth exists at two levels:
Individual bandwidth — how much one performer can process simultaneously. Listening, decoding body language, remembering established facts, planning, and moving the body all compete for limited capacity. (Not literally a single pool — some combinations interfere more than others — but the functional effect is the same: try to do too many and something drops.) When overloaded, reception degrades first — you start missing what's actually happening, catching words but losing tone, or catching the gist but losing the specifics.
Shared bandwidth — the collective processing capacity of the scene, including the audience — who are almost always the bottleneck, since they lack the performers' context, training, and ability to ask clarifying questions. A complex offer (cyborg from the future) consumes more shared bandwidth than a simple one (happy birthday). When shared bandwidth is clogged with exposition or complexity, no capacity remains for the relationship, emotion, or play that makes scenes alive.
Bandwidth is not only cognitive. Emotional processing — absorbing your partner's vulnerability, managing your own fear, staying open rather than defensive — draws from the same finite supply. A performer flooded with stage fright has reduced bandwidth before the first line is spoken.
The 56K modem analogy: your partner and your audience are connecting via limited bandwidth. Large files (complex premises, layered irony) choke the connection. Small files (clear emotions, obvious choices) download instantly. The goal is to keep the channel clear enough for connection to flow. (The analogy is imperfect — improv bandwidth is bidirectional and multi-channel, not a single pipe. But the throttling effect is real.)
Bandwidth recovers. Warm-ups clear the channel. Flow states reduce consumption — automaticity replaces deliberation, so expert improvisers don't have more bandwidth, they waste less of it. The goal of training is not to increase capacity but to stop spending it on internal computation.
Bandwidth is the resource that connects the cognitive-bandwidth law (why it's scarce) to the Be Present and Be Simple principles (how to manage it).