S4h Play Worst Case Reversal

Play: Worst-Case Reversal

Direct brainstorming produces cautious, socially acceptable ideas. Designing the worst possible version removes the social cost of being wrong and unlocks the honest list of everything that actually fails — which, when reversed, becomes the most direct path to the design requirements that matter. The technique works because the worst-possible list is easy: everyone knows how to fail. The reversals do the serious work.

Your Process

Step 1: State the Design Challenge What are you designing, building, or solving? Be specific about the intended outcome — what would success look like if it worked?

Framing check: Confirm the specific design challenge before continuing. State what you've identified — the actual thing being designed and what success looks like — in one sentence, then use AskUserQuestion:

• Question: "I'm reading this as: [your one-sentence framing of the design challenge and its intended outcome]. Is that right?"
• Header: "Framing"
• Options:
  • Yes — proceed — framing is correct
  • Adjust — one element is off; user will correct it before you continue
  • Reframe — different challenge than read; incorporate the correction before proceeding

Step 2: Design the Worst Version Ask: how would you make this as bad as possible? What would guarantee failure, alienate users, destroy trust, waste resources, or produce the exact opposite of the intended outcome? Generate without filter or politeness. Aim for 8-12 specific ways to make it terrible.

Rules for this step:

• No self-censorship. The worse the better.
• Be specific, not vague. "Make users wait 10 minutes" not "be slow." "Never acknowledge errors" not "have bad error handling."
• Include the uncomfortable ones — the ones that reveal real tensions, ignored trade-offs, or problems the current design is quietly making. These are the most valuable entries.
• If it feels too harsh to say, say it. Those are usually the ones that generate the most useful reversals.

Step 3: Reverse Each Failure Mode For each terrible idea, state the affirmative inverse as a design principle. The reversal should be specific and actionable, not generic. "Make users re-enter the same information three times" → "Eliminate all redundant data entry; information provided once should propagate automatically." "Never tell users what went wrong" → "Every failure state names what happened and what to do next."

Step 4: Collect as Design Requirements The reversed principles are design requirements. State them as a clean list, affirmatively, in present tense. These are things the design must do.

Step 5: Audit Against the Existing Design Which requirements were already present and strong? Which were present but weak or inconsistent? Which were missing entirely? The missing ones — requirements that never appeared in the direct design process — are the primary output.

Human Check-in

Before proceeding, use the AskUserQuestion tool. State your interpretation of the situation in 1–2 sentences — what is being analyzed and what the core question is — then ask:

• Question: "My read: [your 1–2 sentence interpretation]. How do you want to proceed?"
• Header: "Scope"
• Options:
  • Full analysis — Complete all steps, reasoning shown throughout
  • Key findings only — Bottom-line output, skip step-by-step detail
  • Reversal list only — The failure modes and their direct inverses, skip elaboration
  • Reframe — The read is off; correct it and the analysis will follow the corrected framing

Proceed based on their selection. If the user reframes, incorporate the correction before running any analysis.

Output Format

Challenge: [what you're designing and what success looks like]

Worst-Possible List + Reversals

Design Requirements Derived: [clean numbered list of all reversed principles]

Audit Against Existing Design

• Already present and strong: [list]
• Present but weak or inconsistent: [list — these need tightening]
• Missing entirely: [list — these are the highest priority findings]

Notes

The uncomfortable entries in the worst-possible list are the most valuable — they surface real tensions that politeness has kept invisible. If every item on your list feels obvious and safe, you haven't gone far enough. Push into the territory where naming it feels a little risky.

What's Next

After delivering this output, use AskUserQuestion to offer the next move:

• Question: "Worst cases reversed. What's next?"
• Header: "Next"
• Options:
  • /s4h-decision-premortem-analysis — Formalise the worst case as a structured premortem
  • /s4h-constraint-workaround-mapping — Address the worst cases with concrete workarounds
  • /s4h-creativity-alternatives — Generate alternatives that avoid the worst cases
  • Done — Wrap up and synthesise what we have so far