how do supply depots work

[randal7]

I have found three explanations online of how supply depots work:

- they add AP to the current total
- they refill AP, up to maximum of 100, but by no more than the amount produced by depot
- they replace current AP if current is lower than what the depot provides

So which one is it? And, as an example, suppose I have two cities 19 hexes apart connected by sealed road. Where should the depot(s) go?

Also I have seen both that depot refills only work once and that depots can be daisy chained indefinitely. How does that aspect actually work?

[zgrssd]

They do 2 - refill AP, up to the original value or a unique limit, whichever comes first.

[Joram]

One thing to note about supply depots though is that they only work once. You can't daisy chain them and extend your supply indefinitely. So at some point another truck depot becomes necessary which, if no other nearby city, could be a great spot to start a new zone.

[Magirot]

And, as an example, suppose I have two cities 19 hexes apart connected by sealed road. Where should the depot(s) go?

Logistics movement costs 7 AP on a sealed road, and lvl 1 truck depots have 100 free AP, so the ideal distance is 100 / 7 = ~14 or less. So in this example, you can add a single supply base 6 hexes away from one of the two cities, which'll both refresh the free AP so it lasts long enough, and the depot won't needlessly accumulate admin strain in the zone (which'll happen for assets that are farther than 6 hexes).

(A rail connection is preferable if the terrain allows it, since they give considerably more logistics points and the allowed distance is 100 / 4 = 25.)

Admin strain is a complicated matter, since cities with a lot of asset levels (so, large cities) can tolerate assets quite far from the city hex without ever accumulating enough admin strain to reach the 10% threshold where penalties start to get applied. The formula is in the manual.

So a large city might well tolerate, for example, a truck station 6 hexes away, and then a supply base, say, 14 hexes away, allowing for full truck action points 28 hexes from the city.