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AB2531 Plague Mod

Black Death Mod by FearSunn reloaded. Plague added to Base game. Harder difficulty setting increases the duration of plague and probability of spreading. Adapted the official Black Death Scenario (that replaces radiation with plague) to regular sandbox game. (Restore the UI, with the tourism diplomatic favor, world congress and Montain constructions that were disabled in the original scenario.)

Gathering Storm DLC required.
NOT COMPATIBLE with any UI mod that edits UnitPanel.lua, PlotToolTip.lua :
- [GS] A Mountain Is Fine Too
- Better unit list
- Community Quick User Interface (Updated Spring 2020)
- Black Death Mod [abandonware]

Assets taken from scenario significantly reworked to fit sandbox game:
Walled District: Hospital, Mass Grave, Keep
Units: plague Doctor, Flagellant, Scholar
Policies: Quarantine Policy, Coerced Work, Studia Generalis

New Spy operation added: Spread plague
Requires to study at least one plague before being available to the spy.

The units that can clean the plague are:
-The Plague doctor
Can be unlocked with the Recorded History civic. Can reduce the plague duration on a tile by 1. Has 3 charges.
- The Scholar
Can be unlocked with the Education technology. Reduce the plague duration on a tile by 2. Has 3 charges. The Scholar can study the plague to unlock the spread ability of the spy and flagellant. The science bonus increases with each era: 60 + currentEra *35. Studying the plague also improves the Minister the Sick ability.
- The Medic
Can reduce the plague duration on a tile by 6. Has 6 charges.
- The Supply Convoy
Can reduce the plague duration on a tile by 12. Has 15 charges.

The other special unit is the
- Flagellant
Can be unlocked after sufficient deaths from the plague in your cities and if you have founded a religion. Can spread the plague only to your own city... He has a PURGE ability that gives (50 + currentEra * 5) faith and (10 * currentEra) culture bonus. It is now a religious unit. Can spread the religion only once but has 140 in theological combat and can be built normally instead of only be bought with faith.

The Plague doctor, scholar and Flagellant can use the Holy fervor ability to continue their actions as long as you have enough faith (cost =10 faith +1 per era)

Main principle: disease start in cities with population more than 4 when at least one of the following conditions is satisfied:
a) city has foreign Trader stationed at the end of the turn;
b) city has negative housing;
c) city is starving (negative food).


City appeal, amenities, city buildings or districts have no effects on plague appearing probability.
Small infected city will lose population 1 per turn. Bigger cities with pop > 10 will lose 2 per turn. Very big cities with pop > 20 will lose 5 if there are no measure taken!
Some building diminishes chances of population loss each turn :
Walled Quarter District = 15%
Plague Hospital building= 15%
Sewer building = 15%
Keep building = 5%
Quarantine policy adds additional 50%
This gives a total of 100% on Prince difficulty and lower.

From any city center, the plague spreads into adjacent tiles.
Probability of adjacent tile to get infected depends mostly if tile has a road and is occupied (by district or improvement).

Also plague won't spread into UNTOUCHED Forest, Desert, Snow, Mountains tiles.

This is intentionally made hard.

In later eras however things get easier.
The initial plague duration on a tile is related with World Era and the difficulty settings
Most severe plague is during Medieval Era.
The duration is for each era : 2 4 6 8 7 6 5 4 3 2 (8 is medieval era)
The difficulty addition is: -3 -2 -1 0 1 2 3 4 (0 is for Prince)
+a random number between 0 and 2
AI cities get a boost for avoiding death depending on the difficulty. The progression is by 10%
0%(Settler) 10% 20% 30%(Prince) 40% 50% 60% 70%(Deity)
Plague started by the spy can last longer depending on the number of studied plague waves.
Infected cities have less loyalty depending on the difficulty.