10-10-10

name	10-10-10
description	Evaluate decisions by considering impact across three time horizons — use when short-term emotions and long-term consequences may point in different directions
argument-hint	[decision you're weighing or struggling with]
user-invocable	true
license	MIT

Break through short-term emotional reactions by evaluating how a decision will feel and matter at three time scales: 10 minutes, 10 months, and 10 years from now. Separates fleeting discomfort from lasting impact. 1. State the decision clearly, including the options 2. For each option, assess: How will I feel about this in 10 minutes? 3. For each option, assess: How will this matter in 10 months? 4. For each option, assess: How will this matter in 10 years? 5. Identify where short-term and long-term assessments diverge 6. Determine which time horizon should carry the most weight 7. Make the decision that optimizes for the right time horizon

<output_format>

10-10-10 Analysis: [Topic]

Decision

[What's being decided, including options]

Time Horizon Assessment

Option	10 Minutes	10 Months	10 Years
A	[feeling/impact]	[feeling/impact]	[feeling/impact]
B	[feeling/impact]	[feeling/impact]	[feeling/impact]

Divergence Points

[Where short-term and long-term assessments conflict]

Dominant Time Horizon

[Which time frame matters most for this decision, and why]

Decision

[The choice, justified by the appropriate time horizon] </output_format>

## 10-10-10 Analysis: Rewrite Legacy Billing System

Decision

Option A: Rewrite the billing system from scratch in a modern stack. Option B: Incrementally refactor the existing system module by module.

Time Horizon Assessment

Option	10 Minutes	10 Months	10 Years
A (Rewrite)	Exciting — fresh start, modern tools	Painful — 6 months in, still not shipped, maintaining two systems	Either transformative (if it ships) or a cautionary tale (if it stalls)
B (Refactor)	Frustrating — same old codebase	Steady progress — 3 modules modernized, billing still works	Fully modernized system, no big-bang risk, but took longer

Divergence Points

10-minute excitement for the rewrite masks the 10-month reality: rewrites routinely take 2-3x estimated time, and the team must maintain the old system in parallel. The refactor feels worse now but avoids the dual-maintenance trap.

Dominant Time Horizon

10 months — this is a business-critical system. The risk of a stalled rewrite leaving the team maintaining two billing systems for a year outweighs the long-term elegance argument.

Decision

Incremental refactor (Option B). The 10-month horizon reveals that the rewrite's main appeal is emotional (fresh start) rather than practical. Refactoring delivers value continuously without betting on a single high-risk cutover.

Key Instructions

• If the user hasn't identified options yet, help them articulate 2–3 distinct choices before running the analysis.
• If all three time horizons point to the same option, state that clearly — the model confirms rather than complicates the decision.

Anti-Pattern Guards

1. Applying the model to non-decisions — 10-10-10 requires genuine options; applying it to informational questions or post-hoc rationalization produces noise, not insight.
2. Treating all three horizons equally — the dominant time horizon varies by decision type; always identify which horizon carries the most weight for the specific context.

Handoff

Chainable to: consider (to apply additional mental models), second-order (for deeper consequence mapping on the chosen option)