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Idea groups

(Redirected from Ideas)
For the ideas of individual countries, see national ideas.
For the ideas of American natives, see native ideas.

As a nation develops technologically, it unlocks the ability to gain additional idea groups. Investing into a full idea group can take a long time and cost several decades worth of power. The act of choosing at any point of time a certain idea group over the other and advancing in it represent the time and focus nations choose to spend historically along certain administrative, diplomatic, and military specializations.


Mechanic summaryEdit

Each nation can have up to 8 idea groups from a pool of 19 groups (only 18 are shown as 2 idea groups are government type exclusive). Idea group choice is only restricted by the requirement for a balanced mix of groups; a new group must not have its affiliated   monarch power be the in same category as more than 50%[1] of the total idea group composition the nation holds at the time. This limit can be turned off before starting a game and works on Ironman. There is no restriction on the groups themselves and any nation may pick any group at any point in the game. That being said, AI nations have had weights assigned to the idea groups to simulate random but somewhat historical idea picks.

Each idea group itself consists of 7 ideas. Advancing within an idea group is done sequentially and each unlocked idea enhances a certain aspect of the nation. Unlocking the last idea in the group also unlocks the group bonus.

Unlocking new slotsEdit

New idea group slots are unlocked with the advancement in   Administrative technology as described below:

  Administrative tech level 5 7 10 14 18 22 26 29
  Number of idea groups 1 2 3 4 5 6 7 8

Abandoning idea groupsEdit

Abandoning an idea group can be used to free up an idea slot if it no longer serves the nation and there may be others more suitable groups that do so. It is important to note, however, that doing so will result in losing all the given bonuses from said idea group and will only refund 10% of the   monarch power points invested in the group[2]. Discarding idea groups will also impact the number of Ideas a nation has towards unlocking National Ideas and Ambitions.

Due to the low refund rate and the importance of monarch power points, picking an idea group should be done with its future usefulness to the nation in mind. However, this option should not be disregarded either as it is extremely useful in the right circumstances. For example:

  • Primitives can take only the first 3-4 Exploration ideas, get a colonial border with a western power, then drop Exploration for something else. Some would benefit more from the Expansion idea group; but Expansion doesn't allow Explorers or long-range island-hopping. They could even opt out of colonization altogether after getting the border they needed.

Technology cost reductionEdit

Each unlocked idea grants a   −2% Technology cost reduction. The reduction can result in up to −14% for a fully unlocked idea group (without accounting for further reductions that may be applied from the ideas themselves). The type of the reduction depends on the affiliation of the idea group; for example, the   Espionage idea group grants   Diplomatic tech cost reduction.


Main article: Policies

Policies become enabled when a pair of 2 idea groups are fully unlocked. Picking a   policy provides a bonus to the nation at the monthly cost of 1 monarch power per policy (type of monarch power used depends on policy affiliation) if the limit is overwhelmed (base: 1 policy of each type can be picked for free) . Once picked, a policy cannot be canceled for a duration of   10 years. There is no restriction on policy composition and a nation can activate up to 9 policies at a time.

Idea cost.pngIdea costEdit

Unlocking an idea has a base idea cost of   400 monarch power[3] (the type of power depending on the idea group).

The base   Idea cost is modified by the following:

−25% for the AI at very hard difficulty
−10% with  Protestant or  Anglican as secondary faith
−7% as  Confucian country harmonized with  Mahayana
−5% with a ruler which has the   ‘Free Thinker’ personality
−5% as  Mahayana country
−5% with “Individual creeds” aspect as  Protestant country
+0.2% for each point of doom of   Nahuatl countries
+20% during the Dominance of the Clergy disaster
+25% during the Janissary Decadence disaster as   Ottomans
+50% during the Dominance of the Tribes disaster

Ideas and policies:

  Traditions Ideas Bonuses Policies
  • Aztec traditions
  • Farsi traditions
  • Incan traditions
  • Ming traditions
  • Rostov traditions
  • Andalusian idea 4: Legacy of Ibn Arabi
  • Antemoro idea 2: Sorabe
  • Aymaran idea 1: Legacy of Tiwanaku
  • Bahmani idea 7: Great Madrasa of the Deccan
  • Bengal Sultanate idea 4: Attract Sufi Scholars
  • Cherokee idea 4: Cherokee Adaptability
  • Colonial idea 4: Free Thinkers
  • Daimyo idea 2: The Bun and the Bu
  • Date idea 3: Renga Group
  • Deccani Sultanate idea 2: Promote Deccani Regional Identity
  • Greek idea 7: Greek Enlightenment
  • Hamburger idea 5: School of the Johanneum
  • Hessian idea 2: Marburg University
  • Hojo idea 3: Reform the Administration
  • Imagawa idea 3: History of the Imagawa
  • Korean idea 6: The Kyujanggak
  • Leonese idea 4: School of Salamanca
  • Madyas idea 1: Hinilawod
  • Maravi idea 1: Fresh Perspectives
  • Mesoamerican idea 1: Olmec Legacy
  • Mexican idea 4: Casa de las Campanas
  • Milanese idea 1: Renaissance Prince
  • Moroccan idea 2: Sufi Marabouts
  • Mughal idea 3: Ibadat Khana - House of Worship
  • Native idea 2: Storytelling Tradition
  • Navarran idea 6: Royal Basque Society
  • Northumbrian idea 6: The Literary and Philosophical Society
  • Orleanaise idea 6: Calvin and Molière
  • Polotskian idea 3: Cultural Center
  • Savoyard idea 5: Savoyard Flexibility
  • Shawnee idea 4: Shaawanwaki Identity
  • Takeda idea 5: Koshu Hatto
  • Thüringian idea 6: Weimar Classicism
  • Tibetan idea 7: The Pale Earth School
  • Toki idea 6: Innovation Over Tradition
  • Trebizondian idea 3: Legacy of the Alexiad
  • Tsutsui idea 7: Tradition and Innovation
  • Uesugi idea 7: Denoku no Ji
  • Welsh idea 6: Prifysgolion Cymru
  • Full Humanist
  • Clevian ambition
  • Granadan ambition
  • Transoxianian ambition
  • Humanist-Trade: Exchange of Ideas
  • Italian idea 1: Italian Renaissance
  • Malayan sultanate idea 4: Classical Malay
  • Swahili idea 4: Indian Ocean Melting Pot
  • Tuscan idea 1: Birthplace of the Renaissance

Decisions and events:

  Event modifier Trigger Duration
+5% Counter-Reformation Catholic decision: “Embrace the Counter-Reformation until one of the following:
  • event: “The Counter-Reformation Ends” (2051): The reformation started 150 years ago.
  • event: “The Counter-Reformation Ends” (2050) for non-Catholic countries.
  • event: “The Counter-Reformation Ends” (2052): has the idea: Liberté, Égalité, Fraternité.
  • event: “The Counter-Reformation Ends” (2053): has the idea: Ecumenism.
  • event: “The King of the Jesuits” option ‘Religious Freedom won the day’.
−5% Islamic center of Scholarly Learning Muslim decision: “Establish an Ibadat Khana until the state religion is changed.
−10% Expanded Royal Bureaucracy Ottoman event: “The Expansion of the Royal Bureaucracy
Option: ‘Expand the Royal Bureaucracy’
until ruler changes.
−10% Kösem Sultana Ottoman event: “Kösem Sultana
Option: ‘Wed Kösem’
until one of the following:
  • until ruler changes.
  • until event: “The Murder of Kösem”
+25% Powerful Magnates Hungarian event: “Decline of Royal Power
Option: ‘Allow the Magnates free reign’
until ruler changes.
−10% Renaissance Glory Neapolitan event: “Renaissance in Naples
Option: ‘An age of Glory!’
for 20 years.
−5% Reichshofrat Austrian event: “Reichshofrat
Option: ‘Create this new council’
for the rest of the campaign.
−10% Reform of the Bureaucracy Austrian event: “The Reform of the Bureaucracy
Option: ‘Reform’
for 20 years.
−25% Prussian Reforms of Enlightenment Prussian event: “The Enlightened Reforms of Frederick the Great
Option: ‘Reforms of Enlightenment’
until ruler changes.
−25% Prutenic Tables Prussian event: “Prutenic Tables
Option: ‘Finance the printing’
until ruler changes.
+10% Sejm Veto Polish culture event: “The Sejm veto all your policies
Option: ‘Ok’
until ruler changes or the event “Pacify the Sejm”.
−10% Sejm complied Polish culture event: “The Sejm comply to your policies
Option: ‘Great!’
until ruler changes or the event “Pacify the Sejm”.
−10% Sigismund's Column Polish event: “Sigismund's Column
Option: ‘Construct Sigismund's Column’
for 30 years.
−5% Merkuriusz Polski Ordynaryjny Polish event: “Merkuriusz Polski Ordynaryjny
Option: ‘Sponsor the newspaper’
until ruler changes.
+25% Konfederacja Polish culture event: “Konfederacja”
Option: ‘Try to negotiate with the konfederacja’
until ruler changes.
+10% Closed China Ming event: “The Closure of China
Option: ‘Close China to the outside world’
for the rest of the campaign.
−10% Open China Ming event: “The Closure of China
Option: ‘Keep trade open for all’
for the rest of the campaign.
−15% Genroku Japanese culture event: “Genroku-era
Option: ‘Start the era of Genroku!’
for 10 years.
−5% Kokugaku Japanese culture event: “Kokugaku
Option: ‘Support the thinkers’
for the rest of the campaign.
−10% Gossip Japanese culture event: “Spreading Rumors
Option: ‘No need to spread foul rumors’
−25% Astadiggajas Vijaynagari event: “Astadiggajas
Option: ‘Let the Prabandha Age begin’
for 60 years. until ruler changes.
−20% Golden age of Timbuktu Songhain event: “Golden Age in Timbuktu
Option: ‘This will last forever...’
until ruler changes.
−5% An Independent Church Ethiopian event: “Independence from the Patriarchate
Option: ‘Our Church should be free of foreign influence.’
for maximum 10 years or until the state religion changes.
−5% Andalucian Moors Moroccan event: “Moorish Refugees for 10 years.
−5% Shiite Migration Persian event: “Shiite Brain Drain
Option: ‘Welcome our brothers.’
for 20 years.
−5% Moorish Refugees Muslim event after the fall of Granada for 25 years.
−10% Celestial Globe[4] Muslim event: “Muhammad Salih Tahtawi - The Celestial Globe
Option: ‘Accept the globe and urge him to create more’
for 20 years.
−5% Mian Mir[4] Muslim event: “Mian Mir
Option: ‘Ask him for advise’
until ruler changes.
−5% Reza Abbasi[4] Muslim event: “Reza Abbasi
Option: ‘Support him and his art’
until ruler changes.
−5% Baha al-din al-Amili[4] Muslim event: “Baha al-din al-Amili
Option: ‘He shall have our support’
until ruler changes.
−5% Serafeddin Sabuncuoglu[4] Muslim event: “Serafeddin Sabuncuoglu
Option: ‘With our help, he shall be able to practice medicine for many more year’
until ruler changes.
−5% Al-Birjandi[4] Muslim event: “Al-Birjandi
Option: ‘I will support his work’
until ruler changes.
−10% Free Freethinkers Event: “Freethinkers Not Persecuted
Option: ‘Brilliant!’
for 10 years.
−10% American Academy of Arts and Sciences[5] American event: “American Academy of Arts and Sciences
Option: ‘Sponsor the academy’
for 20 years.
−20% American Philosophical Society[5] American event: “American Philosophical Society
Option: ‘Sounds impressive, let's sponsor it’
for 20 years.
−5% Sistine Chapel decorated by Michelangelo Papal states event: “Decorate the Sistine Chapel
Option: ‘Hire Michelangelo.’
for the rest of the campaign.
−10% Accademia del Cimento Tuscan event: “Accademia del Cimento
Option: ‘Scientific societies sound like they could be useful someday. Maybe.’
for 10 years.
−5% The Medici Oriental Press Tuscan event: “The Medici Oriental Press for 30 years.
−10% Innovative Court Personality event: “Heresiarch?
Option: ‘The world as a Cheese with worms? Fascinating perspective!’
until ruler changes.

National ideasEdit

Main article: National ideas

Every country has seven national ideas. These ideas do not cost any monarch points but instead are unlocked; one national idea is unlocked for every third idea bought normally from an idea group.

Many nations have unique national ideas while a large number of others have national ideas based upon a common geographic region or a shared culture. The rest of the nations, who lack unique NIs or don't share a common NI group, draw their national ideas from a common generic set of ideas.

National tradition
Every nation also starts with a national tradition: two abilities which define the history and heritage of the country.
National ambition
Countries also have a “national ambition”, which is a bonus that is unlocked when a nation has gained all seven of its national ideas. This bonus is also unique for each country.

Administrative power.png Administrative groupsEdit

Administrative power is required to unlock ideas within these groups.


  Organized Mercenary Payments
−25% Mercenary cost


−25% Core-creation cost

  Benefits for Mercenaries

−15% Mercenary maintenance


−0.5 Interest per annum

  Mercenary Recruitment

+25% Available mercenaries

  Administrative Efficiency

+1 Possible advisor

  Civil Service

−10% Administrative technology cost


+5 Number of states

Associated events: Administrative idea group events


+10% National tax modifier

  Organized Construction

−10% Construction cost

  National Bank

+0.10 Yearly inflation reduction

  Debt and Loans

−0.5 Interest per annum


−0.05 Monthly autonomy change

  Nationalistic Enthusiasm

−5% Land maintenance modifier

  Smithian Economics

+10% Production efficiency


−20% Development cost

Associated events: Economic idea group events


  Additional Colonists
+1 Colonist

  Additional Merchants

+1 Merchant

  Faster Colonists

+20 Global settler increase


−50% Fort maintenance on border with rival
−20% Center of trade upgrade cost

  Additional Diplomats

+1 Diplomatic relation

  General Colonization Law

+1 Colonist
+5% Settler chance

  Competitive Merchants

+20% Global trade power


Can fabricate claim overseas in trade company regions
+5 Number of states

Associated events: Expansion idea group events


+25% Religious unity

  Local Traditions

−2 National unrest


+2 Tolerance of heretics

  Indirect Rule

−10 Years of separatism

  Cultural Ties

+2 Max promoted cultures


+30% Improve relations

  Humanist Tolerance

+2 Tolerance of heathens


−10% Idea cost
+0.25 Yearly harmony increase

Associated events: Humanist idea group events


  Patron of the Arts
−1% Prestige decay


+50% Innovativeness gain

  Scientific Revolution

−10% Technology cost
−10% Institution embracement cost

  Dynamic Court

+1 Possible advisor

  Print Culture

+25% Institution spread


−0.05 Monthly war exhaustion

  Formalized Officer Corps

+1 Leader without upkeep


−25% Advisor costs

Associated events: Innovative idea group events


  Missionary Schools
+1 Missionary

  Church Attendance Duty

−25% Stability cost modifier

  Divine Supremacy

+3% Missionary strength


+2 Tolerance of the true faith
+2 Yearly papal influence
+0.25 Monthly fervor
+0.5 Yearly devotion
+10% Church power

  Religious Tradition

+1 Yearly prestige


−50% Missionary maintenance cost

  Deus Vult

Permanent casus belli against neighboring heathens and heretics


−25% Culture conversion cost

Associated events: Religious idea group events

Diplomatic power.png Diplomatic groupsEdit

Diplomatic power is required to unlock ideas within these groups.


  Foreign Embassies
+1 Diplomat


+1 Diplomatic relation

  Grand Banquets

+1 Diplomat

  Benign Diplomats

+25% Improve relations

  Experienced Diplomats

+2 Diplomatic reputation

  Flexible Negotiations

−20% Province warscore cost

  Diplomatic Corps

−10% Diplomatic technology cost


Lowered impact on stability from diplomatic actions

Associated events: Diplomatic idea group events


  Efficient Spies
+50% Spy network construction
−10% Advisor costs

  Agent Training

+1 Diplomat


+33% Foreign spy detection

  State Propaganda

−20% Aggressive expansion impact

  Claim Fabrication

May fabricate claims for subjects
−25% Cost to fabricate claims


+25% Embargo efficiency
+33% Privateer efficiency

  Audit Checks

−0.10 Yearly corruption


+50% Rebel support efficiency

Associated events: Espionage idea group events


  Quest for the New World
Allows recruitment of explorers & conquistadors

  Colonial Ventures

+1 Colonist

  Overseas Exploration

+50% Colonial range

  Land of Opportunity

+10 Global settler increase


+10% Global tariffs
−20% Envoy travel time

  Free Colonies

−25% Expel minorities cost

  Global Empire

+25% Naval force limit modifier


Can fabricate claim overseas in colonial regions

Associated events: Exploration idea group events


  Tribute System
+25% Income from vassals

  Additional Loyalist Recruitment

−15% Liberty desire in subjects

  Integrated Elites

−25% Diplomatic annexation cost

  Buffer States

+1 Diplomatic relation

  Diplomatic Influence

+2 Diplomatic reputation

  Postal Service

−25% Envoy travel time

  Marcher Lords

+100% Vassal force limit contribution


−50% Unjustified demands

Associated events: Influence idea group events



Not available for primitives.

  Merchant Traditions

+100% Naval tradition from protecting trade

  Merchant Marine

+50% National sailors modifier

  Sheltered Ports

+10% Global ship repair
−10% Sailor maintenance

  Grand Navy

+50% Naval force limit modifier

  Ship's Penny

−10% Ship costs


+1 Leader without upkeep
−25% Admiral cost

  Naval Fighting Instruction

+50% Blockade efficiency
+25% Privateer efficiency


Ships can repair when in coastal sea zones

Associated events: Maritime idea group events


  Shrewd Commerce Practice
+20% Global trade power

  Free Trade

+1 Merchant

  Merchant Adventures

+25% Trade range

  National Trade Policy

+10% Trade efficiency

  Overseas Merchants

+1 Merchant

  Trade Manipulation

+25% Trade steering

  Fast Negotiations

+25% Caravan power


+1 Merchant

Associated events: Trade idea group events

Military power.png Military groupsEdit

Military power is required to unlock ideas within these groups.



Enabled by most monarchies (except the Plutocracy reform), theocracies, steppe nomads, and the Noble Elite republican reform.

  Noble Knights

−10% Cavalry cost
+10% Cavalry combat ability

  Military Traditions

−10% Military technology cost

  Local Nobility

−0.025 Monthly autonomy change
+0.10 Yearly absolutism


+33% National manpower modifier

  Noble Officers

−1% Yearly army tradition decay
−1% Yearly navy tradition decay

  International Diplomacy

+1 Diplomat
+1 Leader without upkeep

  Noble Connections

+20% Available mercenaries


+1 Leader siege

Associated events: Aristocratic idea group events


  Battlefield Commissions
+1 Yearly army tradition

  Military Drill

+15% Morale of armies

  Improved Maneuver

+1 Land leader maneuver

  Regimental System

−5% Land maintenance modifier

  Defensive Mentality

−10% Fort maintenance
+20% Fort defense

  Supply Trains

+33% Reinforce speed

  Improved Foraging

−25% Land attrition


+1 Attrition for enemies

Associated events: Defensive idea group events



Not available for primitives.

  Boarding Parties

+1 Naval leader shock

  Improved Rams

+25% Galley combat ability

  Naval Cadets

+1 Naval leader fire
−33% Morale hit when losing a ship

  Naval Glory

+1 Yearly navy tradition

  Press Gangs

+25% Sailor recovery speed

  Oak Forests for Ships

+20% Heavy ship combat ability

  Superior Seamanship

+10% Morale of navies
+10% Global naval engagement


+10% Ship durability

Associated events: Naval idea group events


  Bayonet Leaders
+1 Land leader shock

  National Conscripts

−10% Recruitment time

  Superior Firepower

+1 Land leader fire

  Glorious Arms

+100% Prestige from land battles

  Engineer Corps

+20% Siege ability

  Grand Army

+20% Land force limit modifier

  Esprit de Corps

+5% Discipline


+5% Recover army morale speed

Associated events: Offensive idea group events



Enabled by most republics (except the Noble Elite reform) and monarchies with the Plutocracy reform.

  Tradition of Payment

+10% Available mercenaries
+2.5% Mercenary discipline

  Abolished Serfdom

+10% Morale of armies

  Bill of Rights

−2 National unrest

  Free Merchants

+1 Merchant

  Free Subjects

+10% Goods produced modifier

  Free Cities

+25% Caravan power


+20% Manpower recovery speed


+10% Institution spread

Associated events: Plutocratic idea group events


  Private to Marshal
+10% Infantry combat ability

  Quality Education

+1 Yearly army tradition

  Finest of Horses

+10% Cavalry combat ability


+5% Ship durability

  Naval Drill

+10% Morale of navies

  Copper Bottoms

−25% Naval attrition

  Massed Battery

+10% Artillery combat ability


+5% Discipline

Associated events: Quality idea group events


  Levée en Masse
+50% National manpower modifier

  The Young can Serve

+20% Manpower recovery speed

  Enforced Service

−10% Regiment cost

  The Old and Infirm

−5% Land maintenance modifier

  Camp Followers

+33% Supply limit modifier

  Conscripted Garrisons

+25% Garrison size

  Expanded Supply Trains

−10% Land attrition


+50% Land force limit modifier

Associated events: Quantity idea group events


Main article: List of idea group events

Idea group events are pulse based events. They occur at regular intervals (5 years) based on the nation's idea groups (not all groups are on the same interval).

In addition, the choice of ideas also has some influence in how often an event may happen, known as MTTH; meaning they can increase or decrease the likelihood of a certain to happened in over other events in their pulse group.

AI preferenceEdit

The AI is dynamically determined according to the current conditions of the country.[6] To decide which idea group it should take, the AI employs a "weight system": each idea group is given a certain weight and the higher this weight is for an idea group, the higher the chances that the AI will choose it. The AI will never choose an idea group with a weight of 0.[7]

Idea group Base weight Weight modifiers[8]
  Aristocratic 0.45
  Plutocratic 0.4
  Innovative 0.3
  • ×2 has a Steppe Nomads government
  • x2 has at least 20 provinces
  • x2 has at least 50 provinces
  Religious 0.9
  Espionage 0.75
  Diplomatic 0.67
  Offensive 0.94
  Defensive 0.77
  Trade 0.7
  Economic 0.85
  • ×1.5 has at least 5 inflation
  • ×1.5 has at least 10 inflation
  • ×2 has a Steppe Nomads government
  • x1.3 has at least 20 cities
  • x1.3 has at least 50 cities
  Exploration 0.75
  Maritime 0.41
  Quality 0.49
  Quantity 1
  Expansion 0.48
  Administrative 0.96
  Humanist 0.9
  Influence 0.5
  Naval 0.31


  1. See in /Europa Universalis IV/common/defines.lua: MAX_IDEA_GROUPS_FROM_SAME_CATEGORY = 0.5,
  2. See in /Europa Universalis IV/common/defines.lua: ABANDON_IDEAGROUP_REFUND = 0.10, -- The part of the idea group spent that will be refunded upon abandonment.
  3. See in /Europa Universalis IV/common/defines.lua: PS_BUY_IDEA = 400
  4. 4.0 4.1 4.2 4.3 4.4 4.5 Only available with Star and Crescent DLC.
  5. 5.0 5.1 Only available with American Dream DLC.
  6. It is still possible to revert to the old system by changing "AI_USES_HISTORICAL_IDEA_GROUPS" to 1 in /Europa Universalis IV/common/defines.lua. Note, however, that the AI will never use historical idea groups in a custom/random setup.
  7. The weights and their modifiers are defined in /Europa Universalis IV/common/ideas/00_basic_ideas.txt at the bottom of each idea group (ai_will_do).
  8. Multiple valid modifiers will stack