Most brand voice documents describe a feeling. Approachable but authoritative. Confident, never arrogant. Read one of those, then try to decide whether a specific sentence follows it. You cannot — and neither can a writer you just hired, or a generator you just configured.
A voice definition is only useful if it settles arguments about individual sentences. That means rules and examples, not adjectives.
Start from writing you already have
Pull five pieces you would be happy to be judged by — a landing page, two posts, an announcement email, a support reply. These are your evidence. A voice invented in a workshop rarely survives contact with real publishing; one extracted from work that already exists usually does.
Read them together and note what is consistently true, not what you wish were true.
- Do you use contractions? (“we are” or “we’re” — pick one.)
- First person singular, first person plural, or neither?
- Do you address the reader as “you” directly?
- Typical sentence length — short and clipped, or long and flowing?
- Do you use humour, and where does it stop?
- How do you handle bad news — hedged, or direct?
Write rules, not adjectives
Convert each observation into an instruction someone could follow without knowing your brand. The test is simple: would two different writers apply this rule and reach the same decision?
| Adjective (useless) | Rule (usable) |
|---|---|
| Adjective (useless)Friendly | Rule (usable)Use contractions. Address the reader as “you”. Never “one” or “users”. |
| Adjective (useless)Professional | Rule (usable)No exclamation marks outside launch announcements. No emoji in body copy. |
| Adjective (useless)Confident | Rule (usable)State claims without hedging. Ban “might”, “could potentially”, “in our opinion”. |
| Adjective (useless)Clear | Rule (usable)Sentences under 25 words. Define any term a new customer would not know, on first use. |
| Adjective (useless)Human | Rule (usable)Open on the reader’s problem, not the company. Never open with “We are excited to announce”. |
Add a banned list
The fastest-acting part of a voice guide is the list of words you never use. It is unambiguous, it is checkable, and it removes the phrases that make copy generic faster than any positive instruction does.
Most lists start with the same offenders: leverage, seamless, cutting-edge, revolutionise, game-changing, in today’s fast-paced world, unlock the power of. Then add the ones specific to your category — the words every competitor uses, which is exactly why you should not.
Show paired examples
Rules cover the cases you anticipated. Examples cover the rest. For each rule that matters, write one sentence that follows it and one that breaks it, on the same subject. A pair teaches a boundary that prose about the boundary never does.
| On voice | Off voice |
|---|---|
| On voiceYour first five posts are free. No card needed. | Off voiceUnlock your content potential with our generous free tier! |
| On voiceThis broke for about forty minutes. Here is why. | Off voiceWe experienced a brief service interruption impacting some users. |
| On voiceIt will not replace your editor. It replaces the blank page. | Off voiceOur revolutionary AI transforms your entire content workflow. |
Keep it to one page
A forty-page brand book gets read once. A one-page reference gets kept open in a tab. If your voice guide will not fit on a page, it contains things that are not rules.
Ten rules
Each testable against a single sentence. If it needs a paragraph to explain, it is not a rule yet.
Twenty banned words
The phrases that would make you wince if you saw them under your logo.
Five example pairs
On-voice and off-voice, same subject, side by side.
One paragraph of context
Who you are writing for, and what they already think about you.
Test it on someone new
Hand the page to someone who has never written for you and ask for three sentences. If what comes back sounds like you, the guide works. If it sounds like a different company entirely, the guide describes a mood — go back to the rules.
Run the same test on your generator: same page, same request, same judgement. Anything a person cannot follow from your guide, a model will not follow either.