created and maintained by Corbeau
Contacts: forum.freeciv.org & Discord (Corbeau#1331)

This document describes v2.1 of the "Simulation" ruleset branch. The v1.0 of this ruleset was used for LT42 game. However, it was somewhat buggy and with surprising elements that took the game to a completely different direction. In this version, main bugs and unwanted surprises have been fixed, but you never know what awaits in that bush over there.

The main part of this document consists of the full description of v2.1. Changes between this and previous versions are appended at the end of the page in raw form. Next public multiplayer game played with this ruleset will be LT48 in September 2019. For more info, check Longturn.net , forum.freeciv.org and LongTurn Discord server .

Introduction

The idea behind this ruleset branch is to make Freeciv game more realistic. Many decisions regarding settings were made based on how a feature should work in reality and not necessarily how it would balance the gameplay. However, Civilization games are very complex and changing one aspect doesn’t necessarily mean disbalancing it, but, rather, re-balancing, only in another configuration. At the same time, in one discussion, a nomenclature was proposed to distinguish games into “strategies” and “simulations”, where “strategies” would require greater skill and experience, while “simulations” would go for more realism and more lenient approach to unskilled players. Even though this argumentation is obviously flawed, I realised that “Simulation” is a good description of the idea of the ruleset and decided to name it so. Everybody is invited to make comments about particular topics in this document, using any of the contacts listed above or, best-case, in this thread on Freciv forum.

The files for the v2.0 of the ruleset are located here:

https://github.com/longturn/games/tree/master/SIM25

Short summary

This ruleset is drastically different from other rulesets that are currently in play and shared around the community. There is a wide collection of changes ranging from city growth and management, government features, to war and unit upkeep. Here is a short list of the most important changes:

Tribal government is the default: low tech, no Trade, cheap Settlers (Tribe)
cities start with minimal working areas (4 tiles only) and grow with size and improvements
units are cheaper to build, but much more expensive to upkeep
unit upkeep is mostly independent of government: the main exception is units in Democracy eating 2x food than in other governments and units under Tribal government not using city's food at all
game starts with all nations under Tribal government; a Palace needs to be built in order to progress to Despotism
there is a class of units (archers, catapults, cannons etc.) with “Bombarder” property: when they attack, they damage the defenders, can’t kill, but in return, do not receive damage when attacking
granary levels are changed: now small cities grow faster and large cities grow slower
spontaneous migration is enabled; population will occasionally move from from smaller and less developed cities into larger and more developed ones if they are close by; this can be controlled with use of some buildings
no civil war; unhappiness does not depend on empire size
corruption depends on distance from the capital; waste depends on tech level only
veteran levels are reshuffled: there are more of them and they increase unit strength mostly by 10%; Also, they are acquired by more improvements, but also some governments

Of course, in order to get a better insight into the changes, check this whole manual.

City management and demographics

Growth and expansion

The most important change about cities is that they have no constant working radius like most “standard” rulesets. Instead, they start at the smallest possible radius which only allows them to work the adjacent four tiles (as marked by red lines when a settler is selected). The radius squared (or r²) grows:

by 1 when city size grows by 1
by 1 when Granary, Courthouse, Barracks (all), Walls, Aqueduct, Harbour are built
by 2 when Mass Transit, Police Station, Supermarket and Sewer System are built

Maximum size that can be reached by adding Migrant units is now 16 (used to be 8 in more standard rulesets).

HOWEVER, Migrant unit is now “unique” which means only one can be in play at the same time. Also, while there is one Migrant unit active, another one can’t be built nor it can be started to be built. Furthermore, by its mere existence, a Migrant unit causes considerable unhappiness in the city where it is built. Minimum distance between cities is 1 (one), which means cities can be placed next to each other.

Building Settlers reduces city population only by 1, not by 2 as in LT rulesets.

Migration

Spontanious migration is enabled. This means that population will migrate from smaller and less developed cities to big ones. There is only partial control over this proces: Granary will decrease the chance of population migrating from the city, while a new improvement, City Hall, will increase the chance of population migrating into the city. Also, size 1 city is less likely - but not impossible - to lose its population and disband due to migration.

Approximate tips (buildings, location and other factors may nullify this):

city size 1 is relatively safe from disbanding by migrating to size 6 or less;
with Granary, city size 1 is relatively safe from migrating to city size 15 or less with City Hall

For technical details, consult Math of Freeciv with the following data:

Migration_Pct adjustments:

city size 1: +100
City Hall: +200
size 1 and Granary: +1000

Food and granary

Foodbox sizes are also heavily reorganised in order to bridge the gap between growing to size 2 and growing to sizes 3 and more. The additional feature of this particular distribution is that small cities grow faster than big cities. The table listing food left after growth (with Granary) and food needed to grow is shown below. Obviously, without Granary improvement, food left after growth in cities with size 5 and more is 0 (zero).

City size	Food after growth	Max food
1	-	10
2	2^F	12
3	4^F	15
4	6^F	18
5	8	22
6	10	26
7	12	30
8	15	35
9	20	40
10	25	50
+1	+5	+10

^F- free Granary

Infrastructure

New building: Manufaktur (with Monarchy) gives +2 Shield to the central city tile; with the passing of time, it represents a "manufacturing tradition" and can't be built once Industrialization is discovered.

NO TERRAIN TRANSFORM (except: ocean <-> swamps)! Instead:

Building a Railroad on hills and mountains gives them +1 Trade
Researching Explosives makes it possible to build Resorts on Hills and Mountains, resulting in +2 Trade
Offshore Platform removed
added Port Terminal: +1 Trade on ocean tiles
farmland can be built in deserts.

Governments, diplomacy, waste and corruption

Most governments have been left intact. However, Tribal government has received a complete rehaul. Also, while Communism has been a bit more differentiated:

Five Year Plan wonders have been introduced for increased production
under Communism, Bank doesn’t give 50% more Luxury and Stock Market doesn’t work at all
celebrating communist cities have increased Shield production instead of Trade

Governments also influence veterancy level of combat units. Units built in Democracy receive no veteran bonus, units built under Republic or Fundamentalism receive 1 veteran bonus level, while all others governments give 2 veteran bonus levels.

All governments except Despotism, Tribal and Anarchy receive +10 Trade in the capital.

When in Anarchy, unhappysize is 1 causing cities to be in revolt by default. Also, specialists have no effect in Anarchy.

Tribal government

Tribal government is now more special. All nations start with Tribal government and need to build the Palace in order to progress to Despotism. Tribal government has the following features:

no Trade
scientists produce 1 bulb (instead of 2)
military units effectively operate without needing food from city granary ("Food Upkeep Free" : 99)
military units produced in Tribalism have 3 Veteran levels; however, Barracks don't have further effect
settlement is performed by "Tribe" unit (obsoleted by Settler as soon as you form a non-Tribal government)
every city produces +1 food on its central tile
once the Palace is built, the capital produces additional +1 food
early governments tile penalty is unconditional: cannot be cancelled by researching Tools or building Pyramids
up to 2 units can provide martial law and they make content 1 population each
by default, cities start becoming unhappy after the 2nd citizen
a nation can not form a Tribal government once Writing or Polytheism have been discovered

New units, unique to Tribal government, are replacing other units that can't be built under Tribal government:

Tribe (replacing Settlers), at half the price
Raiders (replacing Phalanx), can attack from boats
Bowmen (replacing Archers)
Boat (replacing Trireme) - slower, can carry only 1 unit

Trade

Maximum Sci/Tax/Lux rate is reversed: under Despotism you will have full control over your nation and can designate Trade up to 100% for any department. In Monarchy & Communism maximum is 80%, in Fundamentalism it is 70%, Republic has 60% and in Democracy, as a sovereign, you have least control and can only adjust it to maximum of 50%.

Trade routes are not possible because number of routes per city is set to zero. However, it is PROBABLY possible to get a one-time bonus when caravan arrives into a city, but this still needs to be tested.

Waste doesn’t depend on government. Instead, it depends exclusively on technology level. Base waste is 50%. Following techs reduce waste by 5% : Alphabet, Writing, Trade, Physics, Invention, Chemistry, Electricity, Refining, Mass Production, Robotics.

Corruption depends on distance from the capital, except under Communism and Democracy where it is constant throughout the nation. It can be reduced by a number of buildings in the city. However, the effect of a particular building depends on the government. Table below shows corruption reduction by particular buildings for a particular government.

% per tile - for each tile away from the capital, corruption increases for this percentage
100% at - without any buildings, corruption is 100% at this distance from the capital

	Base %	% per tile	100% at	Temple	Courthouse	Cathedral	Police	Library/University
Despotism	25	5	15	25	30	25	10	-
Monarchy	25	4	20	15	40	20	20	-
Funda	25	4	20	30	10	30	20	-
Republic	30	2	25	5	30	20	20	5/10
Democracy	40	-	N/A	5	30	20	20	5/10
Communism	50	-	N/A	-	25	10	30	10

Diplomacy

You don’t need an embassy to make treaties! All your units can serve as temporary emissaries: you can make treaties while - and one turn afterwards - any of your units is in contact with the other nation’s unit. You can still make an embassy for more permanent contact and espionage.

Atlantic Telegraph Company from the LT rulesets, allowing embassies with everybody, is replaced by Marco Polo (Banking). Furthermore, embassies with everybody are automatically created after you discover electricity.

The art of war

One of the biggest changes in the game concerns units. For starters, assume "everything has changed" and, before researching or building a unit, check in-game help. Also, consult this because some change information may be not suitable for in-game help. Detailed table with relevant unit data is appended at the end of this file.

Upkeep

The principle of upkeep has been changed very much and upkeep cost increased. Now units are cheaper to build, but need much more gold, shields and food to be kept operational. Gold cost increases from early ages to the later, and in Democracy financial cost is doubled. Also, more technically demanding units (catapults, ships, armour) also require production upkeep.

Units now need much more food. By default, each unit requires 1 food (except elephants who, naturally, need 2). However, there are two major discounts. Firstly, table below shows “free upkeep per city”.

	Gold	Shield	Food
Anarchy	99	2	99
Tribal	99	1	99
Despotism	2	1	5
Monarchy	2	1	4
Republic	0	0	2
Fundamentalism	2	1	5
Communism	1	2	2
Democracy	0	0	2

Additionally, each 2 city sizes supply free food to one unit. For example, under Despotism, a city size 4 provides 7 units of food to its units at no cost (meaning 7 non-elephant units food-free) because 5 + 4/2 = 7. Note: the core unit of measurement here is “free food”.

Bombarders

Archers, catapults, cannons, artillery and howitzer now have Bombarder property, as well as submarines, helicopters and aerial bombers. This means that, when they attack, they are only able to damage a unit, not destroy it. However, because attacking from distance, they also don’t receive any damage during this attack. (Naturally, if they are under attack from a unit, combat happens normally and they can be destroyed.) Also, when bombarding a stack of units, all units in a stack receive damage. Note: effective strength of Bombarding units is decreased compared to standard rulesets so you will need more of them to seriously damage a well fortified defender.

There have been complaints that this uncovers the number of defenders in a city, but one man’s bug is another man’s feature.

Air units: Bombers AND Fighters are now"Bombarders". The reason for this is that a unit does not represent a single airplane, but an airfleet, and those don't get destroyed, only damaged and reduced. Damaging an airfleet in Civ has the same effect as in reality: it makes it less combat worthy and increases time until it is ready again. Also, make sure the upkeep cost is large enough so that there is no overproduction.

Veteran levels

Veteran levels are no longer 150%, 175% and +25% onwards, like they were in more standard rulesets. Now they are as follows:

100, 110, 120, 140, 150, 160, 170, 180, 200, 210, 220, 230, 240, 260, 280, 300, 330

Also, more buildings make freshly produced units veteran. Barracks will raise veteran level of a unit by 3 (three), while all education, religious and financial buildings will additionally raise veteran level by 1 (one), due to better skills, equipment and morale. Furthermore, as was already mentioned, all governments except Democracy also raise this: Republic by 1 and all others by 2. Because in more advanced societies general population, deprived of the need for rebelion, tends to get lazy.

Movement

Movement cost on some types of terrain is also changed, so be sure to check in-game help.

Military unhappiness

Women’s Suffrage has been removed! If you want your people to accept foreign interventionism, either bring home the goods in the form of luxuries or invest in stupid TV shows.

Relevant for this section: fortress doesn’t change tile ownership.

Under Democracy, a University in the city increases unhappiness by 1 per aggressively deployed unit.

Other conflict-related stuff

city defence bonus rises by 10% per size point until size 10 (max 100%).
Paratroopers and Marines: added "CityBuster" flag - doubled strength when attacking cities.
Helicopters can carry one unit: Land (infantry), Spies, Diplomats and Explorers
on top of the usual, Submarines and Carriers can carry Diplomats, Spies and Missiles
incite city base costs increased x10.
One veteran level lost when upgrading a unit.
Civil war disabled.
NATIONALITY: ON; when you conquer a city, 51% of its population will be unhappy if belonging to the enemy nationality
when your palace is conquered, you don't get another one automatically, you need to rebuild it yourself
no upgrades across classes (cavalry can't be upgraded to armour)
only heavy siege units can reduce city size
no automatic upgrade at all (no Leonardo)
invention does NOT halve the upgrade price
Freight can carry 2 missiles (including Nuclear)
Scorched earth: most or all buildings are destroyed upon city conquest
Bombers losing 20% HP per turn when outside
No units with "Killcitizen" flag: population is not decreased when city is attacked
Caravans and Freights no longer capturable

Technology

Tech upkeep is ON. This means that every turn you pay upkeep in bulbs, depending on how many technologies you have in your knowledge base. The more cities you have, the more upkeep you pay. This has almost no effect in the first part of the tech tree but, for reference, the whole tech tree cost is around 120,000 bulbs which makes Tech Upkeep at the end of the game 120 bulbs per city.

Technical details: Equation: upkeep = ((bulbs / divider) - free) * cities Tech_upkeep_divider set to 2000 Tech_upkeep_free set to 1 (base) and 2 (Tribal only) Among other things, this means no tech upkeep until you research 2000 bulbs worth of technologies (or 4000 for tribal government).

Bridge Building tech doesn't exist anymore. Its role (build roads across rivers) has been taken by Construction.

New tech: Tools (preq: Pottery, Bronze), removes the 3+ penalty (instead of Pyramids and non-Despotism)

New/changed techs:

Physics = Philosophy + Feudalism

Alchemy = Trade + Philosophy

Chemistry = Alchemy + University

Gunpowder = Alchemy + Feudalism

Leadership = Gunpowder + Chivalry

Republic needs Philosophy (was Literacy)

Democracy needs Economics (was Banking)

Exchanging and stealing techs

It is not possible to exchange technologies the conventional way, through diplomatic treaties, but you can use Diplomats and Spies to “steal” them - willingly from your allies or unwillingly from your enemies. Base chance to steal should be 50%. However, previous games showed some discrepancy so we are yet to be absolutely sure how this mechanics actually works. What we are fairly certain is that a Diplomat can NOT steal technology from the same city twice, while Spy may (taking into account other penalties).

Multiple Diplomat units exist, but the only difference is their production cost because “it takes more resources to train them to acquire more complex technologies”.

Barracks, Courthouse, Police Station each add 25% to Spy Resistance (bonus defence for a defending Diplomat/Spy). No defender - no bonus.

Technicalities, tables, appendices, quick reference, stuff&stuff...

veteran_power_fact = 100, 110, 120, 140, 150, 160, 170, 180, 200, 210, 220, 230, 240, 260, 280, 300, 330 veteran_raise_chance = 100, 95, 90, 75, 60, 50, 45, 40, 35, 30, 25, 20, 15, 10, 5, 5, 0 veteran_move_bonus = 0, 0, 0, 2, 4, 6, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18 veteran_work_raise_chance = 50, 20, 15, 10, 8, 6, 5, 4, 3, 3, 2, 2, 2, 1, 1, 1, 0

Units table:

https://docs.google.com/spreadsheets/d/1xP9xlNcQooRPMW0SHJftUdvt6VUUs6KzRd2_BhrnYZs/edit#gid=0

Changes from previous rulesets

Here is a VERY rough and raw list of fixes and changes made between previous versions of the ruleset.

New in v2.1

Tribal government ----- "Tribe" unit - Same as Settler, but:

10 HP
cost 10

Also in Tribal:

+1 food in every city
+1 in capital (Palace) (+2 total)

Tile penalty - unconditional

type = "Martial_Law_Max"
value = 2

type = "Martial_Law_Each"
value = 1

Other:

specialists have no effect in Anarchy
Bombers losing 20% HP per turn when outside
removed Shakespeare's Theatre
No units with "Killcitizen" flag: population is not decreased when city is attacked
Caravans and Freights no longer capturable
Max_Trade_Routes = 0

New in v2.0

When in Anarchy, unhappysize is 1 making cities to be in revolt by default.

- city defence bonus rises by 10% per size point until size 10 (max 100%).

Tribalism: no money (tax or any upkeep cost), no taxmen, scientist gives only half (one bulb), +3 veteran levels

New tech: Tools (preq: Pottery, Bronze), removes the 3+ penalty (instead of Pyramids and non-Despotism)

Fixed Manufaktur: now stops working with Factory built and serves as a museum.

All production bonuses (Factory, Mfg, Plants...) are 50%

Prerequisite switch:

Republic needs Philosophy (was Literacy)

Democracy needs Economics (was Banking)

Tech_upkeep_divider set to 2000

Tech_upkeep_free set to 1 (base) and 2 (Tribal only)

Among other things, this means no tech upkeep until you research 2000 bulbs (or 4000 for tribal government).

Migration_Pct adjustments: size 1, +100; City Hall, +200; size 1 & Granary, +1000 (10^3)

Approximate tips:

- city size 1 is safe from disbanding by migrating to size 6 or less;

- with Granary, s1 is safe from migrating to s15 with City Hall

Equation:

upkeep = ((bulbs / divider) - free) * cities

Anarchy: No Trade!

Monarchy: +10 Trade in capital (Palace)

New units, unique to Tribal government, also replacing other units that can't be built under Tribal government:

- Raiders (replacing Legion and Pikemen), can attack from boats

- Bowmen (replacing Archers)

- Boat (replacing Trireme) - slower, can carry only 1 unit

Bombers AND fighters are "Bombarders". Explanation: a unit doesn't represent a single airplane, but an airfleet, and those don't get destroyed, only damaged and reduced. Damaging an airfleet in Civ has the same effect as in reality: it makes it less combat worthy and increases time until it is ready again. Also, make sure the upkeep cost is large enough so that there is no overproduction.

Scorched earth: most or all buildings are destroyed upon conquest.

Tribal government can't build Triremes, only Boats.

New units: Skirmishers, Arquebusiers, Boats

Arquebusier (2/2 - 20/1) - Gunpowder

Musketeers (3/3 - 20/1)

No more "killcitizen"

Gunpowder = Feudalism + Physics

Leadership = Theology (not Chivalry) + Banking

Removed Leonardo

set diplchance_steal=50

set techlost_recv=0

/set unreachableprotects disabled

Catapult (et al.) should attack non-native tiles.

no upgrades across classes

Add pre-fort (and check fortress border) (terrain.ruleset) - remove "NoAggressive"

All governments except Despotism, Tribal and Anarchy, +10 Trade in the capital

Barracks don't work in Anarchy and Tribal

Farmland can be built in deserts.

Freights can carry 2 Missiles

City foodboxes now corresponding to Manual (now granary_food_ini = 10, 12, 15, 18, 22, 26, 30, 35, 40)

(?) Diplomats couldn't travel by roads and rivers?

Tribal government gets no Trade

Tribal scientists produce 1 bulb (instead of 2)

Tribalism, food upkeep free : 99

Fixed Manufaktur:

+2 shields

with Factory, 2 Trade instead of 2 Shields, no effect on Factory construction

Freight can carry 2 missiles

No automatic upgrade at all

Invention does NOT halve the upgrade price