How I learned how to stop fearing and love the Great Works

General Info

Great Works are unique buildings that can only be built one per province, they're massive investments that generally offer very good bonuses in the short and long term.
Most Great Works will generally require upwards of 1500g to even start the work on one, Then Multiple hundred gold per stage until finished, as well as multiple hundred gold per feature built in them. The features can vary in quality much like the great works themselves. If a ruler decides to do so, they can loot a previously built Great Work for a large sum of money, but will be unable to take advantage of that Great Work so long as they live.

You can reduce the cost of GWs with construction technology as well as the architect trait.

As a general rule of the thumb, GWs will have 8 feature slots when fully upgrades, if you build a GW with the "Build a Great Work" ambition, that first GW will get +1 feature slots.

An important thing to note, is that Great Works require no maintenance fee once fully built, they only have a monthly fee while building.

Many Great Works have Local or General Effects, They are split as follows :
County Wide

• Disease Resistance
  
• Tax
  
• Levy Size
  
• Movement Speed

Character Wide

• Titles
  
• Opinion Bonuses
  
• Artifacts
  
• Decisions

Events & Decisions

Intimidation - Some features enable intimidation as an opton, It has a cooldown of 2 years. Those who have high diplomacy will have a higher chance of success, as well as attempting to intimidate cravens.
The decision gives the following options :

• Gain +20 opinion with the target for 2 years on success, lose -25 opinion for 2 years on failure
  
• Gain a favor with the target on success, loss -25 opinion for 2 years on failure
  
• Gain +5 opinion with the target for 2 years on success, lose -15 opinion for 2 years on failure (higher chance of success than the first option)

Private Conversation - Some features enable Private Conversations as an option, some of which also give intimidation as an option (E.G. Torture Chamber). Private Conversations have a cooldown of 6 months.
The decision gives the following options :

• Attempt to improve relations - +5 Opinion for ?? Months
  
• Attempt to Seduce
  
• Attempt to assassinate (requires 15 intrigue or certain traits).

Burial Ceremony - Great Works that are considered burial grounds (E.G. Mausoleum) will trigger an event on ruler death for a burial ceremony, The options are :

• Expensive Ceremony: Lose between -100 and -400 gold, gain +150 prestige and +50 piety. Characters who liked the dead ruler (+20 opinion or higher) gain +15 opinion of you. Characters who hated the dead ruler (-50 opinion or lower) lose -15 opinion with you
  
• Moderate Ceremony: Lose between -50 and -200 gold, gain +50 prestige and +100 piety. Characters who liked the dead ruler (+20 opinion or higher) gain +15 opinion of you
  
• Cheap Ceremony: Lose between -10 and -100 gold, lose -20 prestige, gain +10 piety
  
• No Ceremony: Lose -50 prestige, -50 piety. Characters who liked the dead ruler (+20 opinion or higher) lose -15 opinion of you. Characters who hated the dead ruler (-50 opinion or lower) gain +15 opinion with you.

Store a Relic - Some Great Work features enable you to store relics, giving you the decision to do so. Religious artifacts can be stored for an immediate gain of piety & prestige, however you will lose the artifact and only one artifact can be stored be Great Work.

• Quality 1 - 100 Piety - 0 Prestige
  
• Quality 2 - 200 Piety - 0 Prestige
  
• Quality 3 - 300 Piety - 100 Prestige
  
• Quality 4 - 400 Piety - 300 Prestige
  
• Quality 5 - 500 Piety - 500 Prestige

Looting Artifacts - Some great works when looted can spawn an artifact for the looter, this can vary from which GW was looted. A list of some of the artifacts are as follows :

• Bells (from a GW with bells (Cathedral)) ,
  
• Magnum Opus on Stellar Astrology
  
• Magnum Opus on Planetary Astrology
  
• Court Etiquette
  
• Kama Sutra
  
• In Honor of My Beloved
  
• The Art of Love
  
• The Illiad
  
• The Oddyssey
  
• Speculum Regale
  
• Apicius
  
• Kitab al-Tabikh
  
• A History of Temples

A Town Is Born - This is a very important event that can be missed, Upon completion of a great work it can spawn a new construction slot for a new City/Temple/Castle for the province of the GW. The requirements for the event to fire is as follow :

• At Peace
  
• Great Work is at least 50 years old (Stage 1 onwards needs to be 50 years old, does not required completed work)
  
• Great Work has at least 2 features
  
• Event has not triggered before on the province
  
• Less than 7 holdings in the Great Work's province

(Be sure to pause your feature's construction so that it finishes while you are at peace if you want this event to fire.)

Crumbling Masterwork - A yearly event that requires a GW that is atleast 100 years old, There's only two options and neither results in anything bad happening to the GW.

• Repair the work - -50g, +40 Prestige
  
• Sell the pieces - +100g

Send Alcoholic Gift - Brewery & Vineyard features enable a targeted decision to gift alcohol within diplo range.

• +10 Opinion for 1 year
  
• +15 Opinion for 1 year for Drunkard recipients
  
• -? Opinion for ? time for Muslims that rejected the gift

Inspired Learning - Great Works and features that improve learning improve the results of the "Invite holy man to court" decision, giving a better chance of the character having higher learning as well as the Erudite or Genius traits.

Generic Features

(These can be built in every Great Work)

Generic Features	Build Price	Monthly Build Price	Build Time	Effects
Great Roads	450g	1g/m	24 Months	+10% Local Movement Speed
Watchtower Network	500g	1g/m	72 Months	+10% Levy Size
Spikes	450g	1g/m	24 Months	+5% Siege Defense, Can be used to execute prisoners, Enables Intimidation
Tower	450g	1g/m	24 Months	+5% Siege Defense, +0.02 Prestige
Hypocausts	300g	1g/m	12 Months	+1% Disease resistance, +0.02 Prestige
Heating Pipes (Req. Hypocausts)	300g	1g/m	12 Months	+2% Disease resistance, +0.02 Prestige
Retinue	550g	1g/m	24 Months	+1 Supply, +10% Garrison, +5% Land Organization(Can recruit "Honor Guard" for 100g = 500 Heavy/1000 Light Infantry - 1.1 Maintenance - Non-reinforcing - Only 1 at a time.)(More likely to remove negative province mods)
Torture Chambers	550g	1g/m	24 Months	+10 Cruel Opinion, Can be used to execute prisoners, enables intimidation & private conversations.
Historic Mural	300g	1g/m	30 Months	+3 Dynasty Opinion
Road Tolls	250g	1g/m	18 Months	+5% local Tax
Torture Chambers	300g	1g/m	18 Months	+5 Drunkard Opinion, Might allow you to remove stressed (Not Allowed for Zealous Muslims)

Great Harbor

Requirement : Coastal

Great Harbor	Build Price	Monthly Build Price	Build Time	Stage Effects
Stage 1	1900g	3g/m	250 Months	+2.5% Local Tax, +25 Trade Value, +0.1 Prestige
Stage 2	1000g	3g/m	300 Months	+2.5% Local Tax, +25 Trade Value, +0.1 Prestige
Stage 3	1000g	3g/m	300 Months	+2.5% Local Tax, +25 Trade Value, +0.1 Prestige
Stage 1	1000g	3g/m	250 Months	+2.5% Local Tax, +25 Trade Value, +0.1 Prestige, -5% Build Cost Modifier

Great Harbor Features	Build Price	Monthly Build Price	Build Time	Effects
Cothon	450g	1g/m	24 Months	+0.5 Supply Limit, +10% Siege Defence
Piers	450g	1g/m	24 Months	+0.25% Local Tax, +0.25 Supply Limit, +30 Trade Value
Harbor Office	450g	1g/m	24 Months	+10% Local Tax, +0.25 Supply
Lighthouse	450g	1g/m	24 Months	+5% Local Tax, +0.25 Supply, +30 Trade Value
Military Wharf	450g	1g/m	24 Months	+50% Galleys, +15% Siege Speed
Master of the Tides	450g	1g/m	24 Months	Unlocks the "Master of the Tides" title which will give +5 Opinion for 1 Vassal

Finalized effect without features : 10% Tax, 100 Trade Value, 0.4 Prestige, -5% Build Cost Modifier

Great Lighthouse

Requirement : Coastal

Great Lighthouse	Build Price	Monthly Build Price	Build Time	Stage Effects
Stage 1	1500g	3g/m	300 Months	+0.1 Prestige
Stage 2	1000g	3g/m	300 Months	+0.1 Prestige
Stage 3	1000g	3g/m	300 Months	+5% Local Tax,+0.2 Prestige
Stage 1	1000g	3g/m	300 Months	+10% Local Tax, +50 Trade Value, +0.3 Prestige

Great Lighthouse Features	Build Price	Monthly Build Price	Build Time	Effects
Treasure Chamber	450g	1g/m	24 Months	Artifacts are less likely to be stolen
Piers	450g	1g/m	24 Months	+5% Morale of Armies
Custodian of the Lighthouse	450g	1g/m	24 Months	Unlocks the "Lighthouse Custodian" title
Lighthouse	450g	1g/m	24 Months	+3 Sex Appeal, Enables Private Conversations

Finalized effect without features : 15% Local Tax, 50 Trade Value, 0.6 Prestige

Ruler Statue

Requirements : Not Humble,Iconclast/Zealous Muslims.

Ruler Statue	Build Price	Monthly Build Price	Build Time	Stage Effects
Stage 1	1500g	4g/m	100 Months	-0.5% Local Revolt Risk, +0.05 Prestige
Stage 2	1700g	4g/m	200 Months	-0.5% Local Revolt Risk, +0.1 Prestige
Stage 3	1900g	4g/m	300 Months	-0.5% Local Revolt Risk,+0.2 Prestige
Stage 4	2100g	4g/m	400 Months	-0.5% Local Revolt Risk,+0.3 Prestige, -1 Short Reign Length

Ruler Statue Features	Build Price	Monthly Build Price	Build Time	Effects
Gold Plating (can only have one plating)	700g	1g/m	24 Months	+0.3 Prestige
Silver Plating (can only have one plating)	450g	1g/m	24 Months	+0.2 Prestige
Bronze Plating (can only have one plating)	350g	1g/m	24 Months	+0.1 Prestige
Additional Statues	450g	1g/m	24 Months	+3 Dynasty Opinion
Watcher of Giants	450g	1g/m	24 Months	Unlocks the minor title "Watcher of Giants"
Golden Crown (Stage 4 Only)	450g	1g/m	575 Months	+3 Vassal Opinion

Finalized effect without features : -2% Local Revolt Risk, +6.5 Prestige, -1 Short Reign Length

Horse Statue

Requirements : Lunatic, Horse Culture or Nomadic Govt. | Not Buildable for Iconoclast/Zealous Muslims.

Horse Statue	Build Price	Monthly Build Price	Build Time	Stage Effects
Stage 1	1500g	3g/m	200 Months	+0.1 Prestige
Stage 2	1700g	3g/m	300 Months	+0.1 Prestige
Stage 3	1900g	3g/m	400 Months	+0.1 Prestige
Stage 4	2100g	3g/m	500 Months	+0.1 Prestige, +10 Horse Opinion

Horse Statue Features	Build Price	Monthly Build Price	Build Time	Effects
Grand Stable	450g	1g/m	24 Months	+5% Mounted Troops, +5% Archers
Additional Animal Statues	450g	1g/m	24 Months	+5 Kind Opinion
Horse Graveyard	450g	1g/m	24 Months	+5 Horse Opinion

Finalized effect without features : +0.4 Prestige, +10 Horse Opinion

Great Library

Requirement : Government isn't nomadic. Need to be a reformed religion.

Great Library	Build Price	Monthly Build Price	Build Time	Stage Effects
Stage 1	2000g	3g/m	320 Months	+0.05 Culture Tech Points, +0.1 Prestige
Stage 2	1000g	3g/m	320 Months	+0.05 Culture Tech Points, +0.2 prestige
Stage 3	1000g	3g/m	320 Months	+5% culture technology spread rate,+0.3 prestige
Stage 1	1000g	3g/m	320 Months	+5% Economy & Military technology spread rate,+0.4 Prestige

Great Library Features	Build Price	Monthly Build Price	Build Time	Effects
Poetry & Drama Collection	450g	1g/m	24 Months	+5% culture tech spread
Architecture Collection	450g	1g/m	24 Months	+5% economy tech spread
Math & Philosophy Collection	450g	1g/m	24 Months	+5% Economy tech spread
History Collection	450g	1g/m	24 Months	+5% Military tech spread
Natural Science Collection	450g	1g/m	24 Months	+5% Military tech spread
Scribe Room	450g	1g/m	24 Months	+1% Tech spread rate, +0.1 Prestige
Keeper of the Tomes	450g	1g/m	24 Months	+5% Culture tech spread, Unlocks the "Keeper of the Tomes" title

Finalized effect without features : +0.1 Culture Tech, +1 Prestige, +5% all tech spread rate

Grand University

Requirement : Tolerance & Legalism 3, Not Nomadic, Religion is Christian,Muslim,Jewish,Zoroastrian,Eastern Religion or Reformed Pagan.

Great University	Build Price	Monthly Build Price	Build Time	Stage Effects
Stage 1	1500g	3g/m	350 Months	+0.05 Culture Tech Points, +0.1 Prestige
Stage 2	1000g	3g/m	300 Months	+0.05 Culture Tech Points, +0.1 prestige
Stage 3	1000g	3g/m	300 Months	+0.05 culture tech points,+0.1 prestige
Stage 1	1000g	3g/m	300 Months	+0.05 culture tech points, +0.02 Economy & Military tech points, +0.1 prestige

Grand University Features	Build Price	Monthly Build Price	Build Time	Effects
Great Seminars	450g	1g/m	24 Months	+10% tech spread,+3 city vassal opinion, +5 Scholar opinion
Wing of Diplomacy	450g	1g/m	24 Months	+0.05 culture tech, +1 Diplo
Wing of Strategy	450g	1g/m	24 Months	+0.05 Military tech, +1 Martial
Wing of Finance	450g	1g/m	24 Months	+0.05 economy tech, +1 Stewardship
Wing of Secrets	450g	1g/m	24 Months	+0.05 Culture Tech, +1 intrigue
Wing of Theology	450g	1g/m	24 Months	+5% Tech Spread, +1 Learning
Guardian of Knowledge	450g	1g/m	24 Months	Unlocks the "Guardian of Knowledge" title

Finalized effect without features : +0.2 Culture Tech, +0.02 Economy & Military tech, +0.4 Prestige

Dos & Don'ts

Time for me to shove my opinions down your throat, I've tried to experiment with a bunch of different things (albeity not all of it) and your experience may vary, but I've tried to give most things a fair trial to determine what all is and isn't worth the time & money.

Generic Features :

The Good :

• Road Tolls - +5% Tax on a province that you probably will have in a Stage 2-3 prosperity on a frequent basis, combine this with nothing but cities for your build slots and you'll be rolling in cash.
  
• Watchtower Network - 10% Levy size is a pretty sizeable increase to your levies.
  
• Retinue - +1 Supply,10% Garrison,5% Land Organization - Just generally good if you're warring alot. (The Honor Guard is a bit lackluster but meh)
  
• Tortue Chambers - +10 Cruel Opinion/Execute Prisoners/Intimidation/Private Conversations - You only need one of these to unlock both Private conversations & execute prisoners, as well as the bonus of +10 cruel opinion which I personally tend to get whether or not I want it on most of my rulers.

The Meh :

• Great Roads - +10% Local Movement Speed , I can see this being useful in areas where transit time is particularly egregious but beyond that, I don't think it's much use.
  
• Spikes - 5% Siege Defense/Intimidation , If you want to unlock intimidation, there's better options, and 5% siege defense will probably only matter in crucial areas, or additionally to something like the Great fortress.
  
• Tavern - +5 Drunkard Opinion/Might remove Stressed - Honestly I wanted to put this thing into the "good" list, because of the sheer fact it can remove stressed, but the rate at which it does so seems incredibly low.

The Bad:

• Hypocausts - 1% Disease Resistance/+0.02 Prestige , Honestly this is garbage, the amount of money this and it's followup take, you could've just built a more cost effective Hospital upgrade.
  
• Heating Pipes - 2% Disease Resistance/+0.02 Prestige , Read Above.
  
• Historical Mural - +3 dynasty opinion , This only gives your own dynasty members a +3 opinion to you, it does stack with other Murals from other GW if you make them, but by itself a +3 isn't likely to stop a jealous cousin gouging your ruler's eyes out.

Great Works

The Good :

• Great Harbor - This thing will make you bank if you have good trading ports personally (E.G. Mahoyadapuram & Cholamandalam in southern india)
  
• Grand university - It takes a while to maximize the usage of it, but the university can offer a straight +1 to all stats for a ruler, increase the rate at which you can get techs, and make the tech spread farther/faster.

The Meh :

• Great Library - This is somewhere between Good and Meh, it primarily offers tech spread rate, which can be immensely helpful but beyond that and the +1 Prestige, it doesn't have much more purpose.
  
• The Gardens - So much promise, but you'll probably not be able to take advantage of alot of it, The disease resist is only for it's local county, The prestige is ok, and you get a negligible (+0.2) health bonus. You can get the vineyard feature which enables alcoholic gifts, Herb Garden which requires you to be part of the hermetic society, as well as a literal fountain of youth which will de-age by 2 years with a 10 year cooldown (unless lunatic), however this feature requires the mystic trait to build.
  
• Great Lighthouse - Only reason this is here and not in bad is because I haven't been able to test it out, the 5% morale buff to armies and the treasure chamber upgrade might make the lighthouse worth it, but if given a choice, the harbor is better in nearly every way.

The Bad:

• Ruler Statue - I was contemplating putting this into "meh" but honestly, it's very expensive for very little, if the revolt risk was in all surrounding areas for example, that'd make it alot better. The Prestige is nice, but there's cheaper options. The +3 Vassal Opinion won't matter as it's too small and will more than likely take an entire ruler's lifetime to make that feature alone. the -1 Short Reign would be nice, but again, too small for the investment.
  
• Horse Statue - It offers little to nothing, it's expensive, and it's a joke.

Additionally : I personally say avoid most of the "title" features, they only offer +5 opinion each, You can however, give multiple to the same person to cheese him.

FAQ & Changelog

v0.1 - WIP, Missing All Religious GWs, Grand Fortress, Walls, Underground City, Amphitheater, Royal Palace, Grand Mausoleam, Great Pyramid, Stone Circle, Aztec Pyramid, All Historical GW

[steve]

I find that the best way to use the build great work ambition is often to build a cheap/fast great work outside your demense up to level 2 and before you complete stage two start building a more expensive/longer one in your demense. That way you can use it to get the extra feature on, say, the Great Walls (where those features go extremely well) without taking the risk of dying in the four decades it will take to get to stage 2.

Also, when you write up the great walls don't forget to mention that the strategic exclaves feature should be delayed until you've filled all the holding slots to maximise the benefits, since the free levels of wall are an event triggered when you build it, rather than a permanent event.

[steve]

You put the gardens in "meh"?! The fountain of youth is more than enough to justify building it. The herb gardens are active if you aren't in the hermetic society, and will occasionally give you a choice between free herbs and +1 health (it's an annual pulse event, so doesn't happen that often, but I've had it plenty of times). Plus it's one of the cheapest great works. If you have the funds to build a bunch of them, you can easily get your health up by enough to be immune to the black death even if the event doesn't fire.

It's worth explicitly stating that if you build multiple versions of the same title feature you get multiple titles, since it's not obvious that they stack.