Air Interdiction Mechanics

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Wiedrock
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Air Interdiction Mechanics

Post by Wiedrock »

No guarantee for the correctness.
If you have any further info/input/corrections, pls let us know!
If you know any other posts related to certain rules, approving/showing them pls also share and I add the links.


Air Interdiction in theory is a tool which has many different aspects to it, which alone may not represent that big of a deal but in sum it would/should give effects that are worth it using Interdiction as an AD.

In this Thread I will try to:
  1. Mechanic: name what mechanics the manual states it should have
  2. Recreate: try to recreate the expected effects
  3. Conclusion: draw conclusions of the tests done
Additionally try to look out for other unknown mechanics along the way.

Not sure yet if I will provide pictures and/or saves/scenarios on tests performed at a later stage.

This color means it is not tested properly yet or WIP.
  1. Rule
    Mechanic: Spread of Interdiction into adjacent Hexes.
    Interdiction attacks will tend to target hexes with a lower movement point cost (i.e.
    the clearer terrain) and will be spread out across the selected target box but focus on
    the places where movement is to be expected. Each interdiction attack hits one hex
    but some interdiction will then be placed in adjacent hexes.
    Recreation: Unclear, unseen.
    Conclusion: Something like this works with Naval Interdiction, but I did not yet see this happen on land hexes.

  2. Rule
    Mechanic: Effect bonus/malus for certain months
    The effectiveness of interdiction bombing will be affected by the weaponry used (18.2),
    the terrain, weather and the detection levels present in the affected hex(es). In
    addition, the time of year will affect the mission as in winter there is less daylight and
    thus it is easier for the enemy to move undetected. The interdiction values generated
    by airstrikes are thus modified by a certain percentage due to the number of hours of
    daylight based on the month as follows
    Jan+Nov(-20)
    Feb+Oct(-10)
    Mar+Sep(0)
    Apr+Aug(+10)
    May+Jul(+20)
    Jun(+30)
    Dec(-30)

    (%-Modifiers)
    Recreation: Successful. Testing 15th June and 15th December 1942 (making all weather the same, "clear"). Assuming a base and multiplicative nature of things the June values should be (1x1.3)/(1x0.7)=1.86→ so 86% larger than those of December.
    Result is ~40-50effect vs ~75-90effect.
    Conclusion: Works as described, comparing June and December as the two extremes.

  3. Rule
    Mechanic: Damage of equipment/freight/goods by Interdiction
    If a depot is present in any hex struck by a ground attack (regardless of notional focus)
    this can result in damage and losses to ground element equipment such as guns as
    well as affecting the movement of freight into and out of those hexes.

    [...]

    Errata 1.04.00: Freight in depots may be destroyed by air attacks targeting a
    port or a railyard. Destroyed freight can cause the loss of equipment and/or
    supplies/ammo/fuel.
    Recreation: no idea. Unclear, unknown, unseen, unapproved so far.
    Conclusion: Beethoven and I tried to figure how/if it works, we back then did not see anything happen. What also does not seem to be possible is the general loss of stored freight in a depot by any mission performed which is/would/could be related to this mechanic.
    It's all rather unclear, there is the possibility that you just need the perfect setup to see it actually happen or it being RNG related and you only can observe it in 10-20% of turns or so.
    So despite it being in the manual the current conclusion is that it does not exist unless proven otherwise.

  4. Rule
    Mechanic: Movement attrition (getting more elements DAMaged)
    Impact of Interdiction. Ground Attack and Naval Patrol Air Directives result in an
    Interdiction Value being placed on hexes. The higher the value [...] the more likely a moving unit will take damage.
    Recreation: Successful.
    Conclusion: It likely is RNG dependent. Seems to work similar to how it works on Seas where you only occasionally get a "loss" message. Possible to be based on a unit's SMP/MP (or something else), similar to what I pointed out in this Thread regarding rail movements where it suddenly pops up when all is "maxed/minimaled out". So in this case when testing the first 3-4 passes through the Hex are all fine but when the units get low SMP/MP the chance to trigger the additional damage pops up.
    So it seems you can completely fine move Divisions several times through even an Interdict 90+ Hex without suffering any additional damage. But then suddenly a Division loses ~7% Ready TOE when it has low SMP/MP (if that's the metric to look at - may also be fully RNG).
    Unclear if the number of Interdiction in a Hex decides chance or amount of damage to a unit when it triggers.

  5. Rule
    Mechanic: Direct damage to units at the end of the Air Phase.
    43.4.1. 01.03.03
    [...]
    Clarification – Ground units can suffer casualties from the interdiction value of the hex
    they are located in at the end of the air execution phase. These losses do not show
    up in a battle report, but are shown in the losses screen as happening during the air
    execution phase.
    Recreation: Failed, units neither suffer DEStruction, nor DAMage, not even FATigue.
    Conclusion: non-existent mechanic or bugged or simply not triggered or looked at it from the wrong POV.

    • 'Replacement-Rule'
      Mechanic: Damage to units by movement attrition listed as Air Phase kills
      NOT MENTIONED IN THE MANUAL
      Recreation: DEStruction by moving through hexes with Air Interdiction is listed as losses in the previous enemy Air Phase.
      Conclusion: not mentioned like that in the manual(?), may be the meant mechanic of Rule above.

  6. Rule
    Mechanic: GS AD effects in battle without GS planes present when a unit's hex contains enemy air interdiction.
    If ground combat subsequently takes place in a hex that has been affected by
    interdiction in the air resolution phase then the detailed combat report (37.1) will show
    the presence of planes (and any damage they cause) even if there was no direct
    ground support.
    Recreation: Successful, also worked in the past.
    Conclusion: As many things it seems to be RNG if the effect triggers, if it triggers with high interdiction numbers it can be rather strong, while otherwise it just isn't there at all.

  7. Rule
    Mechanic: Disabling Administrative Movement
    Administrative Movement is a form of tactical movement that can only be used in
    hexes that were friendly controlled at the start of the turn and have no enemy
    interdiction (22.2.1). This allows units to move faster in each turn as the Movement
    cost per hex is reduced.

    [...]

    Interdiction will affect any enemy movement in the hex(es). This includes the
    movement of ground units (including attacks or retreats), the commitment of reserve
    units to combat, the commitment of support units to combat and the movement of
    freight.

    [...]

    Note that any interdiction >0 has the effect of cancelling
    Administrative Movement (22.2.1) and this also affects the movement
    of freight.


    [...]

    The reduction in the movement cost is based on the lowest quality road system in
    either the source hex or the destination hex. For poor roads, the reduction is 1 MP per
    hex, for average roads 2 MP per hex and for good roads 3 MP per hex. The MP for
    any hex can never be less than 1.
    Recreation: successful
    Conclusion: Works. Did not confirm values 1by1. An example of what it can look like.

  8. Rule
    Mechanic: Adding Tactical Movement Costs
    In addition [...], Interdiction has the effect of raising the Movement cost of each hex once it reaches a certain level (38.7.2).

    [...]

    38.7.2. Air Interdiction and Tactical Movement Costs

    Code: Select all

    Air Interdiction 	Motorized MP 		Non Motorized MP
    1 			NA (1) 				NA (1)
    2 			+1 				NA
    3 			+1 				NA
    4 			+1				NA
    5 			+2 				NA
    6 			+2 				+1
    7 			+2 				+1
    8 			+3 (2) 				+1
    9 			+3 (2)		 		+1
    (1) Note that any interdiction >0 and <1 will still stop administrative movement in that
    hex.
    (2) There is a +2 MP cap on the movement penalty per hex caused by air interdiction
    for motorized units moving in clear terrain.
    Recreation: successful
    Conclusion: Works. Did not confirm values 1by1. An example of what it can look like (see the separate ADs on the southern route to add additional MP costs).

  9. Rule
    Mechanic: MORale Reduction by Air Interdiction
    12.1.4. Adjusting Unit Morale to National Morale
    [...]
    Ground unit morale may decrease due to losing battles, suffering from air interdiction,
    or being in an isolated state. The higher a unit’s morale is over its national morale, the
    greater the chance the morale will be reduced when it loses a battle.
    Recreation: successful
    As of game version 1.04.12 I managed to get it triggered (in the past I failed to get it triggered).
    Spamming Thousands of Sorties per Week in a Hex still only gives a small chance of removing 1 MOR as it seems (needs further testing), with one Hex with 3 Divisions I got one unit lose 1 MOR after 4-5turns with interdiction of 60++.
    Note: There is the possibility that the observed MOR loss may be related to another mechanic I forget about indirectly causing the loss I observed.
    Conclusion: Works, Chance to lose 1 MOR seems random/low even with high Interdiction levels of 60+ in a Hex.
    Needs testing if higher interdiction levels actually increase the chance of losing the one MOR or not.
    Unclear if any leader rolls are involved or there are other metrics to be looked at.
    Seems as if (for now) only MOR above NM levels can be reduced (needs further approval/testing).
    If any Interdiction in a hex causes the same small chance to lose MOR it should be worth it for later periods of the game when German NM decreases.

  10. Rule - LOGISTICS - [several sub-rules may be added]
    Mechanic: Impact on Logsitics
    Recreation: no idea.
    Conclusion: The only worthwile [for now] (likely even too strong effect) is to put the interdiction into a unit's Hex, this makes the unit lose massive amounts of its internally stored/carried freight, which is not a mentioned mechanic in the manual at all (see below) - see a preview here.
    • Logistic-Sub: reducing recived freight+losing trucks (by increasing MP spent for freight)
    • Logistic-Sub: Railway stuff
      Some older Thread(s) on the Matter:
      Railway Interdiction effects, calculations seem to not work as described in the manual.
    • Logistic-Sub: UNKNOWN Rule
      Mechanic: Having Air Interdiction in your Hex during your logistics Phase seems to destroy some of your stored/carried freight.
      NOT MENTIONED IN THE MANUAL
      Recreation: successful
      Conclusion: From an Logistics perspective the most relevant mechanic which is applicaple even in clear terrain with clear ground weather I would propose. - see a preview here
Last edited by Wiedrock on Mon Apr 06, 2026 11:42 am, edited 3 times in total.
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Wiedrock
Posts: 2067
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Location: Germany

Re: Air Interdiction Mechanics

Post by Wiedrock »

2.
Wiedrock wrote: Sun Apr 05, 2026 2:03 pm Rule
Mechanic: Effect bonus/malus for certain months
The effectiveness of interdiction bombing will be affected by the weaponry used (18.2),
the terrain, weather and the detection levels present in the affected hex(es). In
addition, the time of year will affect the mission as in winter there is less daylight and
thus it is easier for the enemy to move undetected. The interdiction values generated
by airstrikes are thus modified by a certain percentage due to the number of hours of
daylight based on the month as follows
Jan+Nov(-20)
Feb+Oct(-10)
Mar+Sep(0)
Apr+Aug(+10)
May+Jul(+20)
Jun(+30)
Dec(-30)

(%-Modifiers)
Recreation: Successful. Testing 15th June and 15th December 1942 (making all weather the same, "clear"). Assuming a base and multiplicative nature of things the June values should be (1x1.3)/(1x0.7)=1.86→ so 86% larger than those of December.
Result is ~40-50effect vs ~75-90effect.
Conclusion: Works as described, comparing June and December as the two extremes.
Testing scenarios: Example pics & math:
December -30%: 54/(1-0.3)=77base effect
June +30%: 91/(1+0.3)=70base effect
interdict_months.jpg
interdict_months.jpg (119.17 KiB) Viewed 474 times
Last edited by Wiedrock on Fri May 15, 2026 8:52 am, edited 2 times in total.
User avatar
Wiedrock
Posts: 2067
Joined: Tue Oct 11, 2022 7:44 pm
Location: Germany

Re: Air Interdiction Mechanics

Post by Wiedrock »

space
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Wiedrock
Posts: 2067
Joined: Tue Oct 11, 2022 7:44 pm
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Re: Air Interdiction Mechanics

Post by Wiedrock »

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