Risk × reversibility

The two axes that decide how much friction a pattern can justify. This is a view of the library, not a way to navigate it — the questions it answers are about coverage, not about finding a particular pattern.

Patterns arranged by risk and reversibility
	Irreversible	Costly	Reversible
Critical	01 The Handoff 04 Appropriate Friction 06 Intent Preview 07 Capability Disclosure 08 Provenance Log 09 Learning Loop 10 Explainable Fault 11 Readiness Check 12 Return of Control 13 Operator-to-Operator Handover 15 Stop Anywhere	03 Graceful Degradation 14 Alert Triage
Elevated		02 The Glass Box 05 Shared Mental Model
Low

3 of 9 cells are filled. A library about autonomy with physical consequences will always lean toward the top-left; the useful question is whether the gaps are real or just unwritten.

Risk

Critical: A mistake can injure or kill, or do damage at a scale that reaches past the people operating it.
Elevated: A mistake costs time, money or equipment, or puts someone in a situation they have to recover from.
Low: A mistake is an inconvenience. Nothing is damaged and nobody is hurt.

Reversibility

Irreversible: Once it has happened, it cannot be taken back.
Costly: It can be put right, but it takes time, money or an apology.
Reversible: Undo it and the world is as it was.