Prompt Frameworks: ABC, CO-STAR, RISEN

Beginner⏱45 min📖6 min readLesson 2 of 5

Prompt Frameworks: ABC, CO-STAR, RISEN

Master three proven prompt frameworks: ABC, CO-STAR, and RISEN, with practical comparisons and examples.

Why Use Frameworks?

Prompt frameworks provide structured templates that consistently produce high-quality outputs from LLMs. They eliminate guesswork and help ensure your prompts are complete, clear, and effective. Without a framework, prompts tend to be vague, miss critical context, or produce unpredictable results.

The Problem with Unstructured Prompts

Issue	Unstructured Prompt	Framework-Based Prompt
Missing context	"Write an email"	Specifies sender, recipient, situation, and desired outcome
Vague instructions	"Make it good"	Defines tone, style, length, and specific requirements
Inconsistent output	Varies wildly between runs	Predictable format and quality
Hard to debug	No clear components to isolate issues	Each component can be tested separately

ABC Framework

ABC stands for Action, Background, Constraints.

Component	Purpose	Example
A: Action	What the model should do	"Write a product description"
B: Background	Context and information	"For a waterproof hiking boot"
C: Constraints	Rules and format	"150 words, friendly tone, highlight durability"

ABC Framework Flowchart

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

ABC Framework Example

[ACTION] Write a professional email response to a customer complaint.

[BACKGROUND] The customer waited 2 weeks for delivery that was promised in 3 days.
They're frustrated but haven't asked for a refund yet. Your company is "QuickShip Inc."

[CONSTRAINTS] 
- Keep it under 200 words
- Apologize sincerely (no excuses)
- Offer a 20% discount on their next order
- Provide a tracking update
- Sign as "Customer Support Team"

💡Tip

ABC is ideal for tasks that have clear instructions but don't require complex role-playing. It's the fastest framework to write: perfect for quick classification, simple content generation, or straightforward email drafting.

ABC in Code

python

# ABC framework applied via API
from openai import OpenAI

client = OpenAI()

def abc_prompt(action: str, background: str, constraints: list[str]) -> str:
    """Build an ABC-format prompt"""
    constraint_text = "\n".join(f"- {c}" for c in constraints)
    return f"""[ACTION] {action}

[BACKGROUND] {background}

[CONSTRAINTS] 
{constraint_text}"""

prompt = abc_prompt(
    action="Write a professional email response to a customer complaint.",
    background="The customer waited 2 weeks for delivery that was promised in 3 days.",
    constraints=[
        "Keep it under 200 words",
        "Apologize sincerely (no excuses)",
        "Offer a 20% discount on their next order",
    ]
)

response = client.chat.completions.create(
    model="gpt-4",
    messages=[{"role": "user", "content": prompt}]
)
print(response.choices[0].message.content)

CO-STAR Framework

CO-STAR stands for Context, Objective, Style, Tone, Audience, Response.

Component	Purpose	Example
C: Context	Background situation	"You're a marketing consultant"
O: Objective	The goal to achieve	"Increase social media engagement"
S: Style	Writing style	"Bullet points, actionable items"
T: Tone	Voice/attitude	"Energetic, encouraging"
A: Audience	Who's reading	"Small business owners new to social media"
R: Response	Format requirement	"5 tips, each with a 'why it works' explanation"

CO-STAR Framework Flowchart

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

CO-STAR Framework Example

[CONTEXT] You are an experienced nutritionist helping busy professionals eat healthier.

[OBJECTIVE] Create a 5-day simple meal plan that requires less than 30 minutes prep per day.

[STYLE] Structured table format with columns: Meal, Ingredients, Quick Tip.

[TONE] Encouraging, practical, non-judgmental.

[AUDIENCE] Software developers working 60+ hour weeks who order takeout 5+ times per week.

[RESPONSE] Include a breakfast, lunch, and dinner option for each day. Add one "emergency snack" section at the end.

ℹ️Note

CO-STAR excels when tone and style matter as much as the content itself. Marketing copy, executive communications, and user-facing content benefit enormously from specifying all six dimensions separately.

RISEN Framework

RISEN stands for Role, Instruction, Steps, End goal, Narrowing.

Component	Purpose	Example
R: Role	Who the AI should be	"Senior Python developer with 15 years experience"
I: Instruction	What to do	"Review and optimize this code"
S: Steps	Process to follow	"1. Identify bottlenecks 2. Suggest fixes 3. Show before/after"
E: End goal	Desired outcome	"Make it run 50% faster and be more readable"
N: Narrowing	Constraints/filters	"No external libraries, must maintain backwards compatibility"

RISEN Framework Flowchart

💡 Tip: Use Ctrl + Mouse Wheel to zoom, or click the fullscreen icon

ℹ️Note

RISEN is particularly powerful for complex tasks where the AI needs to embody expertise and follow a specific process.

RISEN Framework Example

[ROLE] You are a senior UX designer who has worked at companies like Apple and Google. You specialize in accessible, user-friendly interfaces.

[INSTRUCTION] Review this app screen description and identify usability issues.

[STEPS]
1. First, identify 3-5 potential usability problems
2. For each problem, explain why it's an issue
3. Provide a concrete solution for each
4. Rank issues by severity (Critical, High, Medium, Low)

[END GOAL] The output should help the product team prioritize improvements for their next sprint.

[NARROWING] Focus only on mobile usability. Ignore backend concerns and marketing copy. Consider accessibility for color-blind users as high priority.

Framework Comparison

Framework	Best For	Strengths	Weaknesses
ABC	Quick tasks, simple requests	Fastest to write, easy to remember	Less detailed for complex tasks
CO-STAR	Content creation, marketing	Excellent for tone/style matching	More components to remember
RISEN	Complex tasks, expert roles	Step-by-step process, role immersion	Longest to craft, most detailed

Detailed Side-by-Side Comparison

Dimension	ABC	CO-STAR	RISEN
Number of components	3	6	5
Role specification	Implicit (via Action)	Implicit (via Context)	Explicit first component
Step-by-step process	Not supported	Not supported	Built-in (Steps)
Tone/style control	Optional (via Constraints)	Dedicated fields (Style, Tone)	Implicit (via Role)
Audience awareness	Optional (via Background)	Dedicated field (Audience)	Optional (via Narrowing)
Output format control	Via Constraints	Via Response	Via Steps + End goal
Time to write	~30 seconds	~2 minutes	~5 minutes
Best with small context	Yes	Moderate	Can be verbose

When to Use Each

Scenario	Recommended Framework
Quick email, simple classification	ABC
Blog post, social media, marketing copy	CO-STAR
Code review, legal analysis, technical debugging	RISEN
Brainstorming creative ideas	CO-STAR or ABC
Step-by-step tutorial generation	RISEN
Customer support response	ABC
Executive presentation	CO-STAR

⚠️Warning

Don't force a framework for every prompt. For simple questions like "What's 2+2?", frameworks are overkill. Use them when the quality or specificity of output matters.

💡Tip

Combining frameworks: For very complex tasks, you can layer frameworks. For example, use RISEN's Role and Steps structure but incorporate CO-STAR's Tone and Audience components. The best prompt engineers mix and match based on the specific requirements.

📌Important

Framework limitations: No framework guarantees perfect output. They are heuristics, not algorithms. Even the most carefully structured prompt can fail if the underlying model lacks the knowledge or reasoning ability for the task. Always test and iterate.

Applying Frameworks to the Same Problem

Let's apply all three frameworks to the same problem: "Create content explaining AI to executives."

ABC Version

[ACTION] Write a 2-page executive summary about AI.

[BACKGROUND] For Fortune 500 C-suite executives who know nothing about AI.
Company sells enterprise software. Competitors are starting to mention AI.

[CONSTRAINTS] Avoid jargon. Focus on business value not technology.
Include: What AI can do for us, 3 practical use cases, estimated costs/ROI.

CO-STAR Version

[CONTEXT] You're an AI consultant presenting to the executive board.

[OBJECTIVE] Get budget approval for an AI pilot program ($500K).

[STYLE] Executive brief format with clear sections and bullet points.

[TONE] Confident but realistic. Not hype-driven.

[AUDIENCE] CEO, CFO, CTO - all skeptical about "shiny new things."

[RESPONSE] Executive Summary, 3 Use Cases with ROI, Budget Breakdown,
Risk Assessment, Next Steps. All on 2 pages.

RISEN Version

[ROLE] You're a former McKinsey consultant specializing in AI digital transformation.
You've helped 20+ Fortune 500 companies adopt AI.

[INSTRUCTION] Create a persuasive AI strategy document for executive approval.

[STEPS]
1. Start with a 1-sentence "why this matters now" hook
2. Present 3 competitor AI initiatives to create urgency
3. Outline 3 specific use cases with estimated 6-month ROI
4. Include a "no action" scenario showing risks of waiting
5. End with clear "ask" and next steps

[END GOAL] Get verbal commitment for $500K pilot budget by end of presentation.

[NARROWING] No mention of neural networks, training data, or model architectures.
Every claim must be business-outcome focused.

Python: Applying All Three to the Same Input

python

from openai import OpenAI

client = OpenAI()

# Same base scenario for all three frameworks
scenario = "Explain the benefits of cloud migration to a skeptical CFO."

# ABC approach
abc_prompt = f"""[ACTION] Write a persuasive one-page memo about cloud migration.

[BACKGROUND] {scenario}

[CONSTRAINTS]
- Under 300 words
- Focus on cost savings and security (the CFO's priorities)
- Include a 3-bullet ROI summary
- No technical jargon"""

# CO-STAR approach
costar_prompt = f"""[CONTEXT] You're a cloud architect presenting to a CFO who is skeptical about cloud costs.

[OBJECTIVE] Convince the CFO to approve a $2M cloud migration budget.

[STYLE] Executive memo format with clear ROI calculations.

[TONE] Data-driven, confident, conservative with promises.

[AUDIENCE] CFO of a mid-sized enterprise, very cost-conscious.

[RESPONSE] A one-page memo with: 3-year cost comparison, security benefits, migration timeline, and risk mitigation."""

# RISEN approach
risen_prompt = f"""[ROLE] You're a senior cloud architect who has led 15+ enterprise migrations with an average 30% cost reduction.

[INSTRUCTION] Write a persuasive migration proposal.

[STEPS]
1. Open with the cost problem the company faces on-premise
2. Present 3-year TCO (Total Cost of Ownership) comparison
3. List security/compliance benefits
4. Address the CFO's likely objections
5. End with a clear, low-risk first step

[END GOAL] Get approval for a $50K proof-of-concept.

[NARROWING] Only discuss AWS. Ignore multi-cloud. Focus on infrastructure, not application refactoring."""

# Test all three
for name, prompt in [("ABC", abc_prompt), ("CO-STAR", costar_prompt), ("RISEN", risen_prompt)]:
    response = client.chat.completions.create(
        model="gpt-4",
        messages=[{"role": "user", "content": prompt}],
        temperature=0.3
    )
    print(f"\n=== {name} OUTPUT ===")
    print(response.choices[0].message.content)
    print(f"Tokens used: {response.usage.total_tokens}")