Some rules.
1. Never build MICs ever. Not a single scenario where this makes sense. Maybe you tell stories of games where you build an MIC and won. But I can assure you: You did not win because the MIC but despite of it.
2. Facilities neither take territories nor kill they units. You should try to avoid them and focus on investing into units. You need an immediate and relevant impact on investing into a facility. Investing into facilities too randomly with dubious immediate impact will make you lose.
Good examples for facilities can be:
- AB northern Italy in case otherwise the UK has an overwhelming attack on the Italian fleet
- AB Cyprus because it allows to move figs in 1 turn to Moscow
- NB Hainan in order to threaten India or to move transports and fleet in one turn back to sz6
- IC in Kiangsi, FIC or Malaya (many people underestimate the impact of a Malaya IC. In my opinion it is the most powerful one for Japan, although vulnerable. The potential to build units right into sz37 is a pain for the Allies.
- Any kind of “double move AB” = one power enables the planes of a partnered power to move one extra space. E.g. German planes on Italian soil.
Bad examples are:
Almost ANY IC with Germans (except few examples where Yugo IC can make sense)
The Germans can simply conquer enough ICs in order to satisfy their needs for production. ICs in WUK, Caucasus are usually not worth it.
Germans, Ukraine, Novo and Stalingrad are sufficient. There are few situation where a German IC in Persia can make sense. However as I will mention in point 4, ICs can also turn into liabilities.
3. The further the game progresses the more likely it is that a facility can make sense. Early, 15 IPC is a lot. in games where the TUV might stakck up to 3.000 and above, 15 IPCs become less and less relevant. In a late game, 15 IPC invested to give a huge fleet an extra movement and thus extra strategic options can be worth it.
4. Make sure you do not build facilities for your opponent. UK ICs in Persia look neat in the first place, but if the Germans are played well, Allies cannot stop them from moving South and thus capturing the IC which is bad.
Also, when investing into an Egypt IC, make sure you do not lose it to the Italians.
In general I see a tendency that players tend to invest into facilities to easily while not utilizing the maximal impact. Those players get into trouble against opponents who simply plan better without facilities and thus have more units on the map.
So I recommend everybody to stay rather critical when it comes to building facilities and only do so in if you have a strong case!