Give Claude a Role

Tell Claude who it should be — “you are a senior auditor”, “you are a strict English teacher”, “you are a cat” — and its tone, style, and even its accuracy change. This is called role prompting, and the more detail you give the role, the better it works.

The same question, two different Claudes

Without a role, Claude answers plainly:

YOU WRITE

In one sentence, what do you think about cricket?

CLAUDE ANSWERS

Cricket is a strategic bat-and-ball sport that rewards patience, skill, and teamwork across formats ranging from three-hour matches to five-day Tests.

Now the identical question — but with a standing instruction giving Claude a role:

STANDING INSTRUCTION (SYSTEM PROMPT)

You are a cat.

YOU WRITE

In one sentence, what do you think about cricket?

CLAUDE ANSWERS

Cricket appears to be hours of humans chasing a ball I could catch far more gracefully — wake me when someone opens a tin of fish.

Same question, completely different voice. A role changes tone, style, and content at once.

A useful bonus: tell Claude who the audience is. “You are a cat” gives one answer; “you are a cat talking to a crowd of cricketers” gives quite another.

Roles are not just for fun — they improve accuracy

Here is a logic puzzle with a definite correct answer (the answer is yes). Without help, Claude often gets it wrong:

YOU WRITE

Jack is looking at Anne. Anne is looking at George. Jack is married, George is not, and we don’t know if Anne is married. Is a married person looking at an unmarried person?

CLAUDE ANSWERS

We cannot determine this — we would need to know whether Anne is married.

This is wrong. Whether Anne is married or not, a married person ends up looking at an unmarried one either way.

Now give Claude a role that suits the task:

STANDING INSTRUCTION (SYSTEM PROMPT)

You are a logic bot designed to answer complex logic problems.

YOU WRITE

Jack is looking at Anne. Anne is looking at George. Jack is married, George is not, and we don’t know if Anne is married. Is a married person looking at an unmarried person?

CLAUDE ANSWERS

Yes. Consider both possibilities: if Anne is married, then Anne (married) is looking at George (unmarried). If Anne is unmarried, then Jack (married) is looking at Anne (unmarried). Either way, a married person is looking at an unmarried person.

REMEMBER

Give Claude a role that fits the task — a persona for style, an expert for accuracy — and add the audience when it matters. There are many techniques that can achieve similar results; experiment and find your own style.