AI amphibious landing guide

From Hearts of Iron 3 Wiki
Jump to navigation Jump to search

This page aims provide tips and trix to make the military AI preform amphibious invasions.It is mostly based on testing by ArmChairAttila presented in this forum post.

Note that these experiences only concern corps level AI.


  • The corps should only have 3-4 max divisions in it. The AI will not invade if there are 5 land units within the corps level hierarchy. It took about a week for the AI to invade with 4 divisions in my 1st Marines Japanese corps. It invaded instantly with 3 divisions in that corps. So I am concluding that 3 land divisions in the corps level is optimal for AI invasion. Note: you can have one battle fleet and one transport fleet under the corps level command. If you place one battle fleet and 2 transport fleets under the same command the AI will combine the two transport fleets. The AI does not seem act differently with air units.
  • You must have transports that will hold the entire corps. I.E. if you have 4 brigades divisions with * 4 divisions and your HQ is also brigade to the max you need enough transports that will hold the entire corps, including the HQ, in one pickup and drop off.
  • The destination for your invasion should not be connected by land. My marine corps of 3 marine divisions invaded Singapore from Saigon instantly. I tried again when bringing Siam into the alliance and they went the long road through Siam.
  • For the fastest results set AI to blitz, naval/air offensive.
  • Make sure your transport fleet has a range of 3000 kilometers. This is really important, even if the AI can reach invasions spots with a 1500 km transport fleet it will shy away from it.
  • I had my armies attached up to army group level. The invasions seemed to bug out sometimes when attached to theater level. They worked every time when my army group was not attached to theater level.

Observations: The HQ's will take their time getting to the destination but will eventually make it there. Planes, ships, etc. will also start to re base toward your new objectives given some time.