Detection mechanisms & discovery times¶

The city’s sensory apparatus: how failures are noticed, who reports them, and how long it takes for information to reach decision-makers. A failure noticed immediately can be fixed before trust decays significantly. A failure discovered after a week may have already triggered cascades.

Detection mechanisms by type¶

Mechanism	Description	Reliability	Speed	Districts Present
Guild self-reporting	Guilds inform the Patrician of issues in their domain	High (they want protection)	Fast (hours)	Merchant Quarter, Guild HQ areas
Watch patrol	Officers notice failures on beat	Moderate (depends on patrol frequency)	Variable	All, but frequency varies by district
Citizen complaint	Residents report via messengers, clacks, or personal visit	Low in poor districts, High in rich	Slow to Moderate	Nap Hill (fast), Shades (none)
Media investigation	Ankh-Morpork Times reporters discover stories	Moderate (they look for news)	Moderate to Fast	High-influence districts prioritized
Tax shortfall	Budget office notices reduced revenue	High (numbers don’t lie)	Slow (weeks)	All (economic indicator)
Vimes intuition	Commander Vimes “has a feeling”	Paradoxically high	Variable	Anywhere he’s paying attention
Spontaneous event	Explosion, fire, collapse, hard to miss	100%	Immediate	Any
Strategic intelligence	Vetinari’s personal network	Very High	Fast	All (but limited capacity)
No detection	Failure continues until cascade forces discovery	N/A	Potentially infinite	Shades, Cockbill Street

Discovery time base values by district¶

How long before someone in authority notices a non-catastrophic failure (e.g., a broken pump, not an explosion):

District	Base Discovery Time	Modifiers	Rationale
Nap Hill	4-8 hours	Noble complaint accelerates to 1-2 hours	Residents expect service and complain immediately
Merchant Quarter	2-6 hours	Business hours matter; night failures slower	Lost revenue focuses attention
University Precinct	6-12 hours	Wizards may not notice or care	Insulated, self-contained
Isle of Gods	12-24 hours	Temple networks help, but isolation hurts	Community notices, but may handle internally
Small Gods	24-48 hours	No single voice; gradual complaints	Residents grumble but assume no one cares
The Shades	72-120 hours (3-5 days)	No reporting; must be discovered by patrol or cascade	Residents expect nothing
Cockbill Street	120+ hours (5+ days, possibly never)	Pride prevents reporting; active concealment	“We don’t need help”
River Ankh	Immediate if visible (fire, flood), otherwise ignored	Visual events only	Out of sight, out of mind

Discovery time by building type¶

Buildings themselves within a district affect discovery speed:

Building Type	Discovery Time Modifier	Mechanism
Guild HQ	0.5x (half the district time)	Self-reporting
Tavern	0.8x	Customers notice and talk
Civic Amenity	1.5x	May be visited infrequently
Slum Dwelling	2.0x (Shades), 3.0x (Cockbill)	No reporting; active concealment
Artisan Housing	1.0x (baseline)	Neighbors notice
Civic Institution	0.3x (fastest)	Staff present 24/7
Palace	0.1x (effectively immediate)	Vetinari
Unseen University	2.0x (if internal), 1.0x (if external)	They may not tell anyone
Water Source	0.6x	Outright failure spotted fast; slow pressure drops can hide
Power Source	0.4x	Operators and meters spot failure fast
Clacks Tower	0.3x	Tower goes dark; operators and users notice within minutes
Food Supply	0.8x	Market managers notice shortages; contamination hides longer
Brewery	0.5x	Workers monitor vats; contamination can take a day to show
Transport	0.6x	Closure immediate; structural degradation hides much longer
Communications Office	0.8x	Office closure less visible than a tower going dark
Apothecary	1.2x	Small premises; failure surfaces when customer finds it shut
Healthcare	0.3x	Staff 24/7; monitoring equipment; failures spotted at once
Security Post	0.4x	Watch staff notice failures fast; patrol gaps show in reports
Intelligence Service	3.0x	Deep cover; failures surface very late and at one remove
Tech Business	0.4x	Continuous monitoring; alerts fire before humans notice
Hackerspace	1.5x	Operates covertly; disruptions surface slowly and obliquely
Workshop	1.0x (baseline)	Fires obvious; structural decay and contamination hide longer
Fire Service	0.3x	Station staff notice equipment failures and missed calls fast
Media	0.6x	Reporters notice things; their own failures surface gradually

Example calculation:

Small Gods base: 24-48 hours
Small Gods tavern failure: 24-48 × 0.8 = 19-38 hours
Small Gods slum failure: 24-48 × 1.5 (Slum) = 36-72 hours (no, wait, Slums aren’t in Small Gods, let’s do Shades instead)
Shades base: 72-120 hours
Shades slum failure: 72-120 × 2.0 = 144-240 hours (6-10 days)

Detection mechanism effectiveness by district¶

Which mechanisms actually work in each district:

District	Guild Report	Watch Patrol	Citizen Complaint	Media	Vimes	Strategic
Nap Hill	High (nobles)	High	Very High	Very High	Low (rarely visits)	High
Merchant Quarter	Very High	High	High	High	Low	High
University Precinct	Low (UU internal)	Moderate	Low	Moderate	Very Low	Moderate
Isle of Gods	Moderate (temples)	Moderate	Moderate	Low	Low	Low
Small Gods	Low (minor guilds)	Moderate	Low	Low	Low	Low
The Shades	None	Low (infrequent)	None	None	High (when focused)	Low
Cockbill Street	None	Very Low	None (pride)	None	Very High	Low
River Ankh	None (barge guild?)	Low (river patrol)	Low (boatmen)	High (if visible)	Low	Low

Discovery time by incident type¶

Some failures announce themselves; others hide:

Incident Type	Base Discovery Time	Mechanism
Explosion/collapse	Immediate	Everyone notices
Fire	Immediate (if visible), 1-2 hours (if interior)	Smoke, alarm
Water pump failure	District-dependent (above)	Gradual; noticed when people can’t get water
Clacks tower failure	4-8 hours	Users notice, report
Bridge structural issue	12-24 hours (cracks), Immediate (collapse)	Gradual vs. catastrophic
Crime wave	24-72 hours	Pattern emerges slowly
Guild dispute	Immediate (they tell you) or hidden (they don’t)	Political
Supply chain disruption	3-7 days	Shortages appear gradually
Disease outbreak	7-14 days	Symptoms appear, then spread
Strategic interference	Possibly never	Designed to be undetectable

The “Vimes Effect” on discovery¶

When Samuel Vimes is personally focused on an area, discovery time collapses:

District	Normal Discovery	With Vimes Attention
Nap Hill	4-8 hours	2-4 hours (he’s efficient)
Merchant Quarter	2-6 hours	1-3 hours
University Precinct	6-12 hours	4-8 hours (he intimidates wizards)
Isle of Gods	12-24 hours	6-12 hours
Small Gods	24-48 hours	8-16 hours
The Shades	72-120 hours	4-8 hours (he walks the beat)
Cockbill Street	120+ hours	2-4 hours (they tell him everything)

Mechanism: Vimes walks, talks to people, and has a network of informants (and former street urchins) who trust him. In the Shades, he’s the only authority figure who isn’t a threat.

Cost: Every hour Vimes spends in one district is an hour not spent in another. His attention is a scarce resource.

The “Moist Effect” on discovery¶

When Moist von Lipwig is assigned to fix something, discovery accelerates because he’s looking, but initial reports may be unreliable:

Phase	Discovery Speed	Reliability
First 24 hours	Very Fast	Low (he’s guessing)
Days 2-3	Fast	Improving
Day 4+	Very Fast	High (he’s figured it out)

Mechanism: Moist talks to everyone, charms information out of people, and isn’t afraid to ask stupid questions. He also cuts corners, so initial assessments may miss underlying issues.

Discovery time cascades¶

A failure discovered late has already caused damage:

Day 1: Pump fails in Cockbill Street (no report)
Day 2: Residents carry water from Small Gods (resentment builds)
Day 3: Small Gods pump strained (but not failing yet)
Day 4: Shades residents notice Cockbill Street neighbors using "their" pumps
Day 5: Inter-district tension; minor fights
Day 6: Cockbill Street elder finally walks to Pseudopolis Yard (6 hours)
Day 7: Vimes learns of problem; visits immediately
Day 8: Pump repaired

Trust impact by day of discovery:
- If discovered Day 2: -5 trust (Cockbill), 0 elsewhere
- If discovered Day 7: -20 trust (Cockbill), -5 (Small Gods, Shades), inter-district tension penalties
- Repair cost: Same (pump fixed), but relationship repair needed

Strategic detection¶

Lord Vetinari doesn’t rely on official channels. His personal detection mechanisms include:

Mechanism	Coverage	Reliability	Discovery Time
Palace clerks	All written reports	High	Daily summary
Personal spies	Key individuals, guilds	Very High	Hours to days
Assassins’ Guild intelligence	They share selectively	Variable	Depends on relationship
Dinner invitations	Nobles talk	Moderate	Weekly
Reading between lines	All communications	Extremely High	Immediate (to him)
The “Vetinari pause”	He already knew	100%	Before you did

Mechanism: Vetinari has arranged information flows so that he receives multiple independent reports on any significant matter. Discrepancies between reports tell him as much as the reports themselves.

Detection difficulty by district¶

District	Easy to Detect	Hard to Detect	Effectively Invisible
Nap Hill	Water failure, crime, transport	Internal noble conspiracies	-
Merchant Quarter	Business disruption, guild disputes	Quiet criminal coordination	-
University Precinct	Explosions, visible magic	Internal faculty politics	Most things (they hide)
Isle of Gods	Bridge issues, temple disputes	Gradual infrastructure decay	-
Small Gods	Catastrophic failures	Slow degradation, minor crimes	Most routine failures
The Shades	Fires, collapses, visible deaths	Pump failures, disease onset, crime patterns	Everything until cascade
Cockbill Street	(Nothing without Vimes)	Everything	All failures concealed
River Ankh	Fires, floods, visible pollution	Gradual siltation, contamination	Baseline condition

Discovery time as a strategic variable¶

The Patrician can invest in improving detection:

Investment	Cost	Effect	Districts Affected
More Watch patrols	Budget (ongoing)	Discovery time -25%	All, but especially Shades, Small Gods
Citizen reporting incentives	Budget (small)	Complaint frequency +50%	Medium-influence districts
Clacks redundancy	High (capital)	Communications failure detection immediate	All with clacks
Guild liaison officers	Political	Guild reporting improves	Guild districts
Vimes overtime	Vimes exhaustion	His attention spreads thinner	One district at a time
River monitors	Moderate	River issues detected faster	River Ankh
Shades outreach	Political (nobles object)	Discovery time in Shades -50%	Shades, Cockbill Street

Detection metrics framework¶

Metric	Behaviour
Base discovery time	Function of district (wealth, influence) and building type
Detection mechanism effectiveness	Different mechanisms work in different districts
Vimes effect	His attention collapses discovery time in poor districts
Moist effect	Fast discovery, initially unreliable
Vetinari effect	He already knows (narrative convenience)
Investment options	Budget can improve detection, but trade-offs exist
Cascade penalty	Late discovery = more trust damage, harder recovery