The intelligence system in HoI3 is a critical component of successful gameplay. Failure to use the intelligence system properly will assuredly result in ahistorical outcomes and grave disadvantage.
This mission kills all hostile spies, so if you are in the Axis faction, you can send your spies to Germany and they will kill only the spies that are not German, Japanese etc. Spies set to Counter Espionage kill every foreign spy they can find. This is incredibly useful for maintaining a high quality spy network. This is the most common mission for domestic spies, due to the tendency for the AI to use spies to sabotage your research projects. It is also useful in an offensive role however. At first if the enemy has a large number of foreign spies in their country you will actually help the enemy by killing large numbers of them. The chance of what countries spy you find and kill seems to be random, but you will eventually begind to kill domestic spies. Once those spies are killed the opposing country will not be able to conduct counter espionage until they replace their spies, which requires them to spend leadership, and allows you to conserve leadership since your own spies are much less likely to be killed. Counter espionage also seems to have an easier time killing new arriving spies rather than entrenched old spies. Another observation is that counter espionage seems not to target spies of your ally.
- Enables you to establish 'espionage superiority', leading to lowered leadership cost in the long run.
- Forces the enemy to dedicate additional leadership to espionage to rout spies.
- Can possibly be used to help protect weaker allies from espionage attacks.
- Allows spies to perform useful missions longer.
- Kills all spies, which may actually assist the target country in the short term by removing penalties imposed by foreign spies.
- Waiting to eliminate target countries domestic spy network delays them from performing other more useful tasks, like increase threat, or disrupt national unity.
- Can lead to an espionage war, forcing you to spend leadership on spies to establish the upper hand.
- Because the majority of foreign spies in the target country belong to you, they're much more likely to be targeted by the target countries remaining counterespionage units.
As of TFH, this mission shows you a random selection of enemy forces on the map. It's useful mainly in MP.
If you steal a technology, you steal ones that the other nation has already researched, and they keep them as well. Success rate is acceptable if the other nation has much better techs, and abysmal if tech levels are pretty much the same. The success rate can't be influenced by techs.
This has the effect of raising another nation's threat rating over time. There are, however, a couple of mitigating factors:
- A country's threat is evaluated on a state-by-state basis. A mission to raise the threat of the UK will raise it at different rates for every state. So the UK may appear more threatening to Denmark than it does the US.
- This effect is based on distance. The US is less threatened by European states than by, say, Mexico.
- Large countries or perhaps countries with better counter-espionage don't raise threat as quickly.
The increase threat action is more effective when brokered across multiple nations within an alliance. For example, Germany can more effective raise threat in the Allies if it is doing it against both the UK and France. As more members join the alliance, there is greater potential for spy penetration to further increase the threat.
Increasing the threat on a minor power is an interesting alternative in order to promote one's own alliance. The threat raises quicker when done against a minor power, and nearby nations will be more likely to join your alliance.
Scouting and Covert Missions
These were added to the intelligence missions with TFH. Spies sent on Covert operations generate Covert ops points which can be either used for Coups on the Espionage screen, or used for tactical operations, which can be accessed by selecting a province on the map and pressing the Covert operations button. It takes 15 covert points for each mission. Just how long it takes to build up to the maximum of 50 points depends on the resistance your intel efforts are meeting. In any event, it takes a long time to build up 50 points. It may take a two-year effort, so the sooner you start on it, the better. If you have the required covert points, the options can be displayed from the top right arrow from any enemy or friendly province info box. Used to maxiumum effect, they can change the game totally in your favour.
With the longer campaign against Russia, it could be possible to gain another 10 covert points before winter (using 45 points at the outset plus 10 making a total of sixty) enabling the use of 4 covert missions.
Tactical covert ops missions The Covert Operations mission increases the number of covert points you have in a nation. When you are at war, you can use these on a province to increase/decrease supply flow (for everyone), recon a province, or do a coup. For the latter you need a lot of points and patience. When you do have enough points, click on the province window, then on the "covert ops" button on the right (just under the province picture) and select the type of mission you want:
- Sabotage Strategic Resource: This mission lets you sabotage a strategic resource in a single province.
- Scout/Sabotage Area: This simulates things like sending in under cover scouts, or sabotage all road signs in an area. It will slow down enemy movement, or speed up your movement.
- Steal Local Battle Plans: This mission can give you a local intelligence advantage and reveal unknown units.
Decryption helps you gather intelligence of the enemy, either through having troops in a neighbouring province, Military espionage, or RADAR stations. The intelligence level will increase, so if you would at first just see that there were three enemy divisions, you could now possibly see that the enemy has 9 INF brigades and 3 ART brigades. Encryption works the other way around, for the enemy.
To be able to gather intelligence with RADAR installations, you need to research a tech. The listening range of RADAR increases with its level but not the range is at which it helps aircraft, which is always the province it is in plus the adjaencet provinces only. See Air_combat#Radar_impact for more information on Radar.
A strategy guide on alignment, threat and neutrality: Propaganda and You: A Strategy Guide