Hearts of Iron 4 is a World War 2 grand strategy game that does its best to simulate the tragic events of the time in a realistic way for the players to roleplay and lead any country of that time to glory or ruin.
In an attempt to simulate the general mindset of the era, the game has implemented a mechanic that keeps track of the uneasiness of the world and the willingness to take military action to stop aggressors around the world.
Recommended Read: How to Refit Ships in Hearts of Iron 4
This mechanic is called “World Tension” and it allows players to take actions which were impossible at the start of the game, to simulate the reticence of the Allied forces while the Axis were expanding left and right.
To increase World Tension, you can justify war goals on countries, declare war, send volunteers, and even just join a faction. There are a lot of actions that increase World Tension, and most are related to negative interactions with other countries.
Table of Contents
- What is World Tension?
- How to Increase World Tension in HOI4
- Who Needs to Increase World Tension?
- How World Tension Affects Game Mechanics
- All Events in HOI4 That Increase World Tension
What is World Tension?
World Tension is a meter that records the hostile and aggressive actions of the countries in the game.
Each time someone declares war, annexes territories, or does anything that could be considered dangerous, overall World Tension increases.
This meter is also useful for unlocking various diplomatic options, since most Democratic countries can’t really interact properly on the world scene with others until World Tension increases to a certain percentage.
Luckily, if your goal is to keep democracies in check, then you’d want to keep World Tension low for as long as possible.
World Tension also decreases by 0.5% every month, with the minimum WT being 25% after the threshold has been passed.
How to Increase World Tension in HOI4
The most common way of increasing World Tension in HOI4 is declaring war on a country. However, most countries can’t do that until World Tension reaches a certain threshold.
So, here is a full list of the reasons why World Tension could increase:
- Declare war
- Puppet, annex, or take land (through peace deals or focus tree events)
- Send volunteers
- Join a faction
- Justify a wargoal
- Revoke a guarantee
Generally, as a democracy, you won’t be able to do any of the things listed above. Most of them won’t even affect World Tension if you are democratic.
However, as a fascist or communist country, almost everything you do will affect World Tension.
The best way to generate World Tension is by justifying war on other countries. Specifically, faction leaders like the UK. When you select to justify on the United Kingdom you will see that you will generate a lot of World Tension.
However, the World Tension won’t just instantly appear, it will slowly grow as you are justifying on the country.
This is why this is the best way to increase World Tension fast and also avoid an all out war with someone you’d rather face later in-game.
Wait while the war justification is being fulfilled and cancel it before it’s done. The World Tension will still have been increased and you won’t lose anything from the whole thing besides the initial Political Power.
Generally, it’s a bad idea for fascist and communist countries to raise World Tension, since this allows democratic countries to become more powerful and interfere in their wars.
Who Needs to Increase World Tension?
There are only two countries that need specific World Tension thresholds to be passed to start completing unique national focuses in their trees:
- Canada
- United Kingdom
For Canada, you will need 5% WT to complete the Shadow Factories focus, which grants you 3 Mils, and 20% for Defence of Canada Regulations, which is vital for getting all the good focuses in Canada’s tree.
If you are going ahistorical, you’ll also need 15% for the Dominion of Canada Rifle Association, which helps with Infantry Equipment production.
The United Kingdom has a lot of focuses that require high World Tension. To get rid of the horrible The War to End All Wars debuff, you’ll need 50% WT.
This generally stops the UK from getting some of their best focuses until at least 1938, when Germany does the Anschluss.
How World Tension Affects Game Mechanics
World Tension can also decide for most ideologies what diplomatic options they can use:
Justify War goal
- Democracies can only use this diplomatic option if World Tension is 100%.
- Non-Aligned can only use this diplomatic option if World Tension is 50%.
- Fascists and Communists can always use this diplomatic option.
Guarantee independence
- Democracies can only use this diplomatic option if World Tension is 25%.
- Non-Aligned can only use this diplomatic option if World Tension is 40%.
- Fascists and Communists can only guarantee countries with the same ideology.
Create faction
- Democracies can only use this diplomatic option if World Tension is 80%.
- Non-Aligned can only use this diplomatic option if World Tension is 40%.
- Fascists and Communists can always use this diplomatic option.
Start Lend lease
- Democracies can only use this diplomatic option if World Tension is 50%.
- Non-Aligned can only use this diplomatic option if World Tension is 60%.
- Fascists and Communists can only use this diplomatic option if World Tension is 50%.
Send Volunteers
- Democracies can only use this diplomatic option if World Tension is 50%.
- Non-Aligned can only use this diplomatic option if World Tension is 40%.
- Fascists and Communists can always use this diplomatic option.
All Events in HOI4 That Increase World Tension
Here is a list of all the events that happen when following historical focus paths, until 100% World Tension is reached:
- 11 March, 1936 – Rhineland, +5% World Tension
- 17 July, 1936 – Spanish Civil War, +0.5% World Tension, Volunteers +2% World Tension
- 16 December, 1936 – Anti-Comintern Pact, +2% World Tension
- 1936 – Ethiopia Capitulates, +1.2% World Tension ? Total World Tension at the end of 1936 = 8%
- 21 March, 1937 – Anarchist Spain, +0.5% World Tension
- 14 July, 1937 – Marco-Polo Bridge Incident and Sino-Japanese War, +8.8% World Tension ? Total World Tension at the end of 1937 = 13%
- 10 February, 1938 – Anschluss, +12% World Tension
- 3 August, 1938 – Bulgaria Focus, +1% World Tension
- 7 September, 1938 – Sudetenland and Hungary Focus, +5% World Tension ? Total World Tension at the end of 1938 = 25%
- 25 January, 1939 – Eastern Claims, +3% World Tension
- 5 April, 1939 – Fate of Czechoslovakia, +5% World Tension
- 11 May, 1939 – Albanian Occupation, +2% World Tension
- 14 June, 1939 – Italy Joins Axis, +1.4% World Tension
- 19 July, 1939 – Baltic Claims, +1% World Tension
- 23 August, 1939 – Danzig or War, +13% World Tension, Capitulation +3.1% World Tension
- 3 October, 1939 – Germany attack the Netherlands, Belgium, Denmark, and Norway, USSR attacks Finland, +39.1% World Tension ? This leads to WW2 and 100% World Tension
That’s everything you need to know about how to increase World Tension in Hearts of Iron 4!
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