The Napkin Test, and When It Lies to You
We have been saying a version of this for a while: if an idea cannot be explained in a simple drawing, it probably is not worth making.
It is a good line. It is also false. The task is working out which part.
Where It Works
The napkin has a real tradition behind it. Dan Roam wrote a book on solving problems with rough pictures. Amazon threw slide decks out of its meetings in favor of written narrative, on the reasoning that a weak idea can hide behind bullet points and cannot hide in prose. The elevator pitch runs on the same logic.
The common thread is a category of idea whose value lives entirely in its structure: a product concept, a business model, an org chart, a user flow, an argument. For those, compression genuinely is a test. If you cannot draw the shape, you probably do not have the shape, and the fog you mistook for depth is only fog.
That is the honest version of the claim, and it is a strong one. A rough sketch is the cheapest available way to discover whether a structural idea coheres, and it is usefully merciless. You cannot draw a hand-wave.
Where It Fails
Now the part the slogan gets wrong.
An enormous number of worthwhile things have no compressible structure at all, because the value is the detail.
You cannot sketch a novel. You can sketch its plot, and the plot is the least interesting thing about it. You cannot sketch a piece of legislation, a proof, a piece of music, a performance, or a joke. The joke dies in summary precisely the way jokes do. Anything whose worth accumulates across time or texture will flunk the napkin test while being entirely worth making.
The heuristic carries a bias: it rewards ideas that are easy to explain, which is not the same as ideas that are good. Simple pitches win rooms. That is a fact about rooms, not about ideas.
There is also the line that if you cannot explain something simply you do not understand it, usually pinned on Einstein with no evidence whatsoever. Pleasing thought. Not obviously true. Some things are hard because they are hard.
The Version That Survives
Not "if it cannot be drawn, it is not worth making." Instead:
If an idea's structure cannot be drawn, you do not yet understand its structure, and it is far cheaper to learn that on a napkin than six months in.
That keeps the useful part, the sketch as a cheap early test, and drops the arrogance of insisting everything valuable is simple. Most things worth doing are not. Some have a simple skeleton, and finding out whether yours does takes about four minutes and a pen.
Why We Care
We build a place for fast rough drawings, so of course we are biased toward the sketch. But the sketch is not valuable because simple things are better. It is valuable because it is cheap, and cheap tests are how you avoid burning a year on something whose shape was wrong from the first day.