Side-by-Side Comparison
| CO-STAR | RISEN | CRISPE | |
|---|---|---|---|
| Components | Context, Objective, Style, Tone, Audience, Response | Role, Instructions, Steps, End goal, Narrowing | Capacity/Role, Insight, Statement, Personality, Experiment |
| Optimises for | How the output reads | How the task is executed | Range of alternatives |
| Best for | System prompts, brand and audience-specific content | Analysis, planning, step-by-step technical tasks | Creative briefs, marketing copy, ideation |
| Unique component | Separate Style and Tone | Narrowing (explicit exclusions and limits) | Experiment (ask for multiple versions) |
| Output | One on-voice answer | One structured, complete answer | Several variations to choose from |
| Token cost | Low to medium | Low to medium | Medium (multiple outputs) |
| Difficulty | Intermediate | Intermediate | Intermediate |
When to Use CO-STAR
Pick CO-STAR when the same assistant or content type has to sound consistent across many inputs. Its distinguishing idea is that Style (structure, formality, density) and Tone (emotional register) are specified separately, and that the Audience is described precisely enough for the model to calibrate vocabulary and depth. That makes it the natural choice for system prompts, support assistants and brand content.
When to Use RISEN
Pick RISEN when success depends on the model following a process. Steps fix the order of work, the End goal defines what "done" means, and Narrowing lists what to exclude or which limits to respect. It is the most direct way to turn an internal briefing or standard operating procedure into a prompt.
When to Use CRISPE
Pick CRISPE when you do not yet know what the best answer looks like. The Personality component sets the voice, and Experiment asks the model for several versions, which turns a single prompt into a small A/B test. It is well suited to headlines, campaign angles and creative concepts.
One Task, Three Frameworks
The task: an announcement email for a new offline mode in a note-taking app.
CO-STAR
Context: We make a note-taking app for consultants. Version 4 adds full offline mode. Objective: Get existing users to update and try offline mode this week. Style: Short paragraphs, one bullet list of what works offline, no jargon. Tone: Confident and practical, not hype. Audience: Busy consultants who work on trains and planes and have lost notes before. Response: Email under 150 words with a subject line and one call to action.
RISEN
Role: You are a product marketing manager for a B2B note-taking app. Instructions: Write the launch email for our new offline mode. Steps: 1) Subject line. 2) One-sentence hook about losing notes. 3) Three bullets on what works offline. 4) Update instructions. 5) Call to action. End goal: Existing users update to version 4 and open a note offline this week. Narrowing: Under 150 words. No discounts, no competitor mentions, no exclamation marks.
CRISPE
Capacity and Role: Act as a senior B2B copywriter. Insight: Our consultants often work without internet; version 4 adds full offline mode. Statement: Write the launch email announcing offline mode. Personality: Calm, confident, a little dry. Experiment: Give me three versions with different hooks: fear of loss, productivity, and freedom to work anywhere.
Notice how CO-STAR produces the most consistent voice, RISEN the most predictable structure, and CRISPE the widest range of options.
Decision Guide
- Writing a system prompt or brand voice guide? CO-STAR.
- Turning a process or checklist into a prompt? RISEN.
- Need several creative options to choose from? CRISPE.
- Need all three? Start with RISEN for the task, add CO-STAR's Tone and Audience, and finish with CRISPE's Experiment line.
Frequently Asked Questions
Which is better for system prompts: CO-STAR, RISEN or CRISPE?
CO-STAR is usually the best fit for system prompts because its separate Style, Tone and Audience components define how an assistant should communicate across many different user messages. RISEN is better when the system prompt mainly describes a procedure the assistant must follow. CRISPE fits when you want the assistant to offer several variations by default.
What is the main difference between CO-STAR and RISEN?
CO-STAR specifies how the output should read (style, tone, audience, response format). RISEN specifies how the task should be done (instructions, ordered steps, an end goal and narrowing constraints). CO-STAR is communication-first; RISEN is process-first.
What does the E in CRISPE stand for?
The E stands for Experiment: you ask the model for several alternative outputs instead of one, so you can compare and pick or combine the best. It is the component that most clearly separates CRISPE from CO-STAR and RISEN.
Can I combine CO-STAR, RISEN and CRISPE?
Yes. A common pattern is RISEN's Role, Instructions and Steps for the task, CO-STAR's Tone and Audience for the voice, and CRISPE's Experiment component to request three variations. Keep each component to one or two sentences so the combined prompt stays readable.
Which framework is easiest for beginners?
RISEN is the easiest to learn because its components map directly to how people already brief a colleague: who you are, what to do, in which steps, towards which goal, within which limits. CO-STAR takes a little more practice because Style and Tone are easy to confuse.