You face a continuum from acceptable to unacceptable:
Strategic precommitment to defend arbitrary boundaries on slippery slopes: Establish a conspicuous, defensible line that takes on significance as a coordination point, preventing gradual erosion toward undesirable outcomes.
Core insight: When facing slippery slopes, the strongest defense isn't always at the most justifiable position—it's at the most obvious, unambiguous line where everyone can coordinate to hold the boundary.
Source: Scott Alexander (Slate Star Codex), 2012, building on Thomas Schelling's concept of focal points
You face a continuum from acceptable to unacceptable:
Challenge: Each marginal step seems small and justifiable in isolation, but the cumulative effect is disastrous.
Schelling point: A salient, obvious boundary that serves as a natural coordination point even without communication.
Schelling fence: A deliberately established Schelling point used as a precommitment device to resist incremental erosion.
Key properties:
Not defending the optimal position—defending the most defensible position:
The first example in each pair is more arbitrary but clearer—that clarity makes it holdable.
Personal commitment devices:
Interpersonal boundaries:
Policy and governance:
Slippery slope prevention:
What's the undesirable end state you're trying to avoid?
Map the continuum from current state to disaster state.
Look for conspicuous boundaries along the continuum:
Good Schelling points:
Bad Schelling points:
Critical insight: Place the fence before the truly problematic region.
Why: If you try to defend right at the edge of disaster, small violations are catastrophic. If you defend early, small violations are just small violations.
Example:
Build in margin for error.
Make the boundary mean something beyond its literal position:
Explicit precommitment: "I'm setting this boundary and I will defend it"
Public commitment: Tell others—social cost of violation reinforces boundary
Link to values: "This represents my commitment to X principle"
Create ritual: Make crossing the boundary require deliberate ceremony/justification
The boundary's power comes from its significance, not just its position.
Zero tolerance for violations: Every exception weakens the fence.
Resist "just this once": If it's justified this time, it'll be justified next time.
Escalate defense: Treat boundary violations as more serious than the marginal harm—you're defending the fence itself, not just the immediate issue.
Make exceptions explicit: If you genuinely need to move the fence, do it deliberately and establish a new one—don't just let it erode.
When the fence is violated:
Every violation you tolerate becomes precedent for the next.
Defending indefensible positions: Putting the fence at an awkward, hard-to-explain place. Pick obvious boundaries even if they're not theoretically optimal.
Too many fences: If you have 20 bright-line rules, none are bright. Choose the critical boundaries.
Justifying exceptions: "This situation is special" is how fences erode. Exceptions should be extremely rare and involve moving the fence deliberately, not ignoring it.
Arguing the fence position: Getting into debates about whether the specific line is optimal. The fence's value is in its defense, not its specific location—don't undermine it by admitting it's arbitrary.
Not making boundaries visible: A fence you can't see or verify compliance with doesn't work. Make violations obvious.
Gradual movement: Slowly shifting the fence 5 minutes at a time. Defeats the purpose—fence should stay put or move in deliberate, discrete jumps.
Product development: "No features that require >2 clicks" prevents gradual UX complexity creep. Each individual extra click seems fine, but the fence holds simplicity.
Engineering standards: "All code requires tests" prevents gradual erosion to "most code has tests" to "important code has tests" to "tests are optional."
Personal productivity: "No phone use before 9am" prevents checking "just one thing" spiral. Arbitrary but defensible.
Free speech policy: "No content moderation based on viewpoint" is clearer than "moderate extreme content"—the fence prevents incremental expansion of "extreme."
Commitment devices: "Zero alcohol during work week" easier to maintain than "moderate drinking"—no decisions, just a rule.
Behavior change: "Gym every weekday morning" beats "exercise regularly"—the fence is conspicuous, violations are obvious.
Pre-establish fences before temptation: Set bedtime policy when well-rested, not when tired at midnight. Set expense rules when solvent, not when vendor offers "special deal."
Use existing Schelling points: Don't create arbitrary boundaries from scratch—anchor to existing round numbers, natural categories, social norms. Leverages existing salience.
Make fence public: Social pressure reinforces personal commitment. "I don't drink on school nights" is easier to maintain when friends know the rule.
Celebrate fence defense: Each time you successfully hold the boundary in face of temptation, reinforces its significance. "I wanted to stay up, but I held the 11pm line."
Create friction at fence: Add verification, reporting, or ceremony required to cross. Makes violations deliberate, not accidental.
Multiple parties share fence: Team agreement on boundary makes defense easier—"we don't ship without tests" is stronger than individual commitment.
When to move a fence:
How to move a fence without eroding it:
Never: Just ignore the fence when inconvenient and hope no one notices. That destroys the fence's credibility.
Physical fence properties:
Schelling fence inherits these: The rule isn't just a guideline—it's a defended boundary with significance beyond its specific position.