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Subject: Discussion on USN air system and some suggestions rss

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Robert McCoy
South Korea
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A comparison of the differences of the two air combat systems, original verse deluxe and some suggestions on how to make it better. This version is an update after I put together a revised Coral Sea mini-scenario. It has a few clarifications, and one or two further modifications.

CAP in original USN

NAC from CVs only protect naval units and naval bases and attack any aircraft tasked to air-strike these targets.

LAC from Airbases protect Land units and other land installations in their hex.

air-to-air combat.

3 possible combats:

1. Naval CAP (NAC from CVs) attack incoming enemy aircraft that are targetting ships in TF or under CDUs as well as Naval bases.

2. Land CAP (LAC or NAC) over airbases attack incoming aircraft targeting Land units, CDUs, naval units under CDUs, and Air or Naval bases for air bombardment or strafing.

It is interesting to note here that air units bombing naval bases or ship units under a CDU could both be attacked by both types of CAP though the CDU could only be protected by land CAP.

3. LAC still aloft or remaining from the the the above air-to-air combat attack aircraft assigned to offensive ground support in their hex.

In this system, aircraft assigned to defensive ground support are not engaged in air-to-air combat, nor do they suffer any losses due to anti-aircraft fire unless they are supporting a unit which is being attacked by an enemy unit that is in control of a friendly airbase in the hex. They get what some would call a 'free pass'.

Only CAP units and units being attacked by them can fire. Naval and Land CAP operate in virtual different dimensions and never fire at each other.

CAP in USN deluxe

All NAC and LAC that are assigned to CAP in a hex form one large CAP group.

Units flying any mission also add their attack factors to CAP, but if such units' air points make up 51% of the total then shift one columnt to the left when resolving air-to-air combat -- this is called air superiority.

air-to-air combat is now one single combat. Players then proceed to the bombing resolution — naval units, bombardment and ground support.

All units that fly a mission are now included in the air-to-air combat, including units assigned to defensive ground support. Thus it is possible to have LAC assigned to ground-support firing at NAC assigned to naval CAP. Somehow they encounter each other though the intent of their tasking may be quite different.

The apparent problem:

The above system leads to far greater attritional losses for both players. And the Japanese would probably get the short end of the stick in a long campaign. The war would be over by mid 44 latest.

The Air superiority mission where units are deliberately assigned to defensive ground support in anticipation of missions in the hex would inflate this attrition even further. Many have argued it introduces an indirect CAP, especially when the point of conflict is obvious. The only penalty being the one shift left on the CRT.

There are a few ways to address this problem:

1. Reintroduce a separate naval CAP that protects naval units at sea, and during air-to-air combat there is a shift left on the air-to-air chart for air units assigned to bombing the ships; bombing is not affected. Air units assigned to land CAP and units on the air superioty mission cannnot intervene. There are now two air-to-air battles — one is for Naval CAP verse air-naval bombardment. The other is for land CAP/air superiority verse enemy land CAP/air superiority. Only NAC based on CVs can perform naval CAP; NAC assigned to this mission may only fire at enemy air units bombing naval units at sea (not naval units under a CDU). Both NAC based on CVs and LAC based on airbases may perform the Land CAP mission in a hex. Land CAP attacks all other air units on other missions — that is they do not attack enemy air units assigned to bombing of naval units at sea; they can attack air units bombing naval units under a CDU. Enemy land and naval CAP in the same hex never initiate any combat with each other.

If either side has 11% or more of the their air points in an air-to air-battle on a CAP mission then apply the normal USN Deluxe rules as paragraph G under phase 5 mutual air-strike. If both sides do not have 11% or more of their total 'land mission' air points on the CAP mission then all air strength points are halved when resolving an air-to-air battle not one shift left as in the regular air superiority rules.


1. A side with 50% or more planes on CAP fire at their normal numerical total strength.
2. If either side has 11% or more planes on CAP then they both fire at their numerical total strength adjusted one column to the left even if one side has less than 11% of its planes on CAP.
3. When both sides have less than 10% of their planes on CAP then numerical strength is halved before firing.

EXCEPTION: If both sides only have air units on bombing missions at extended range or LBAC in a hex then there is no air superiority battle as there are no fighters present. Further, if there is no CAP in a hex and only one side has NAC or LAC at normal range on bombing missions then that side has the option of completing its bombing mission with no air superiority battle being fought. This reflects how a bombing mission can have more priority than gratuitously engaging in a target of opportunity.

OPTIONAL: Force co-ordination problem: If there is enemy CAP or NAC/LAC at normal range committed to an air battle then a firing player may exclude all enemy NAC or LAC flying extended range and LBAC from his opponents combat total. Such planes may neither fire or be fired upon during the air-to-air combat phase and are put aside until the flak and bombardment phases. The choice is made after the CAP force percentage is calculated and may change the firing capability (intensity) of the air units involved in the battle, so sometimes it is not a good idea. This rule gives a player with a smaller CAP or air superiority force some flexibility on limiting his opponents total fire power. It simulates that such planes at extended range may get 'lucky' but others have already paid the price.

'land mission' = any mission that is not naval CAP or bombardment of naval units at sea.

The phasing would change:

1st Air-to-air battle — Naval CAP verse naval bombardment missions at sea, - both sides fire and extract losses.
Follow the normal sequential procedure for LBAC, LAC and NAC groups.
Execute Flak fire - extract losses.
Perform air-naval bombardment missions and apply damage or remove sunk ships from play.
Air units that have performed this mission stay aloft and are now out of battle until the landing phase.

2nd Air-to-Air battle — Land CAP/air superiority fire verse all air units on 'land missions' - both sides fire and extract losses.
resolve any attacks of naval units under CDUs. Execute flak fire and extract losses then perform air-naval bombardment mission.
resolve land bombardment missions. Execute flak fire for all remaining missions, extract losses then perform bombardment or strafing missions.
Finally, implement ground support missions.

Go to landing phase.

Some flexibility is still there:
a. NAC on CVs can still be assigned to Land CAP in the same hex. This is how you would neutralize enemy CAP over an enemy held hex, and friendly air units on bombing missions would have the benefit of CAP protection.
b. NAC units on naval CAP can engage enemy NAC on naval CAP in the same hex, and it is theoretically possible in such a case not to have a shift left penalty for air units performing bombing of naval units because their CAP might be over 50%. (But a surface engagement might be a problem.) It is also possible to have an 'air superiority' battle between two enemy forces both on the air-naval bombardment mission in the same hex, again unlikely though except in points of friction like Guadalcanal.
c. As for NAC based on a CV under a CDU, they may not perform a naval CAP mission, but they may perform a land CAP mission.

This is my favoured solution as it cuts down on the attrition and puts a premium on having planes assigned to the CAP mission. Having a separate NAC verse naval air-strike units that battle over TFs is more in the spirit of the original design and perhaps better simulation. The 11% rule represents that air units on bombing missions have been tasked with bombing and stick to business. Further, they don't have a lot of time to shoot each other down as they are watching their fuel gauges. Thus a minimal amount of planes on CAP in the mix is needed to increase the intensity of the battle.

[optional: Where a force consists of 81% of air units assigned to CAP, then shift one to the right, but be careful -- this might make naval CAP more effective than historical.]

The indiirect CAP problem is still there, but hopefully is more manageable without the magnified attrition. On the other hand planes tasked with various missions still run into each other within reason.

I tried to follow Einstein's dictum of 'make everything as simple as possible, but not simpler.'

Examples for idea #1 above:

1. 16 Japanese NAC are performing a naval bombing mission and targeting the Lexington (CV-2) and CA-1 which are paired together for flak purposes as they are at sea. The Allied player has 7 NAC on CAP from the Lexington.

The Allied player fires his CAP of 35 strength points and gets a '5' which results in 2 aborted and 1 destroyed Japanese NAC. 13 NAC proceed to target. The Japanese roll a '2' which results in 6 aborted and 5 destroyed for the Allied player who must destroy 5 NAC and abort his remaining 2 on CAP. The Japanese player had to reduce his fire to 70 to 79 column as his planes were on a naval bombing mission. 17 flak factors fire at the remaining Japanese NAC and get a '6' so the Japanese do not suffer any losses to flak. This leaves NAC with 91 bombardment verse the Lexington's defense of 2 for a 36-1 attack on table 3. A '1' is rolled followed by '2' on the damage table. The Lexington is sunk. Fortunately for the 2 surviving CAP they can land on the Yorktown (CV-5) which was not targeted, is in the same hex and has spare capacity.

2. 9 Allied NAC are performing a naval bombing mission and targeting the Shoho (CVL-2) which is paired with TR-1 for flak fire as they are at sea. The Japanese have 3 NAC on CAP from the Shoho.

The Japanese player fires his CAP of 15 strength points and gets a '1' result so the Allies must destroy 1 NAC and abort 2. The Allies return fire on the 30 to 39 column which was shifted down from the 40 to 49 column because the Allied NAC are performing a naval bombing mission; a '4' is rolled which results in 1 destroyed and 2 aborted NAC for the Japanese. The 6 remaining Allied NAC undergo flak fire of 15, another '1' is rolled and another NAC is destroyed and two more NAC abort. 3 Allied NAC may now attack at 33 to 1 on Table 3. A 3 is rolled for the 6 column on the damage table where a 2 is rolled which results in 40 weeks damage for the Shoho. The two Japanese NAC that aborted back to the Shoho are destroyed as they had aborted immediately onto the Shoho during the air-to-air combat. There was no other airbase or CV for them to land in the hex in any case.

It should be noted that in the above two examples of combat that if they were fought in a hex with an airbase, no LAC/NAC assigned to land CAP or on air superiority would be able to participate in the air battles.

Example 3 (hypothetical) This example assumes players are using the spotting rules proposed by D. Love.

The Japanese have taken Espirutu Santo and have built a 10 capacity airbase there.
The Yorktown just lost half its NAC in a miscarried raid and is hiding with CA-1 and DD-1 under the CDU in Noumea (hex 899).
The arrogant Japanese have sent two CVs (CV-3 and CV-4 carrying 16 NAC) with escort CA-1 and CA-2 into the Noumea hex to finish them off; this operation will be assisted by 8 LAC from the new Japanese airbase on Espiritu Santo. Unbeknownst to them the Enterprise (CV-6 with 10 NAC) is sitting off New Caledonia in hex 966 and has not been spotted. The airbase in Noumea only has 5 LAC at the moment with the Yorktown still being able to scrape together another 5 NAC.

Example 3a:The Japanese have decided they have sufficient forces to both wipe out the LAC on Noumea and sink or badly damage the Yorktown. They send 3 LAC to strafe the airbase on Noumea. 10 NAC will be on Land CAP while 2 NAC and 5 LAC will deal with the Yorktown (naval bombing mission) under the CDU while 4 NAC are held back as naval CAP just in case.

The Allied player has decided to defend the Yorktown as he has lost too many carriers in the war already. So the 5 LAC and 5 NAC (Yorktown) are put on land CAP [note the Allied player may not put any NAC on naval CAP as he has not CVs at sea in the Noumea hex]. The Enterprise launches all its planes, 10 NAC, at the Enemy task force on a Naval bombing mission.

First the air-to-air combat at sea is fought. The Japanese have 4 NAC for a strength of 20 and fire at the NAC attacking from the Enterprise. They are caught by surprise and roll a '6' aborting only one NAC; the allied player fires on the 40 to 49 column (one column shift down from 55) which results in 3 abort 2 eliminated; the two aborted Japanese NAC prudently land on CV-4. 9 allied NAC proceed to the target (Japanese CV-3 which is paired with CA-1). Flak of 22 strength points fire and get a roll of '2' for 3 abort and 1 destroyed. 5 NAC with a bombardment of 55 to the CVs defense of 2 is a 27 to 1 on the air to surface table. They roll a '3' which puts them on the '4' column for damage, guaranteeing some damage. They roll a '1' and CV-3 (Zuikaku) now has 20 weeks of damage.

Second the air-to-air over land is fought. The Japanese do not shift down for air superiority as they do not have less than 50% air points on CAP for a total of 100 strength points to the Allies 50 strength points. The Japanese roll a '2' which inflicts 10 eliminated and 9 aborts. The Allied player's CAP is eliminated with zero planes left in Noumea. The Allied player fires with his 50 strength points rolls a '2' as well for a result of 3 eliminated and 4 abort and chooses LAC as his target . The Japanese player chooses to eliminate 3 LAC (naval bombing) and aborts 4 more LAC on naval bombing and strafing. The leaves Japanese player with 1 LAC on strafing verse a flak of 10 air and 2 NAC on naval bombing that has a flak total of 48. The reason the Japanese chose to eliminate his LAC on naval bombing was that he now has no chance of getting to the Yorktown. The Allied player rolls flak (base [10] + Yorktown [15] + CA-1 [10] + DD-1 [13] for a total of '48') and rolls a '2' which easily eliminates both remaining NAC. The base now fires 10 flak at the sole LAC remaining which was assigned to strafing and rolls a '4' which aborts it back to base.

Both sides have problems. For the Allies, the Yorktown (CV-5) is an empty carrier and CAP protection over Noumea is non-existent. For the Japanese, their mission miscarried, and they have a seriously damaged CV on their hands as well as having lost 8 NAC ( 2 air-to-air, 2 flak and 4 couldn't land). The Yorktown has got to run, the Japanese need to get their damaged carrier to a safe place, Noumea base is howling for re-inforcementsm, and the Enterprise is lurking. My best guess is both sides might withdraw for a week or two.

In a real game, many players would opt to sacrifice the Yorktown and do a mutual strike, so the Japanese actually got off lightly. On the other hand, the Japanese player could have chosen to keep all his NAC on naval CAP which would have had its own consequences. The Japanese player also miscalculated in the amount of planes he would need to bomb the Yorktown thus having his NAC on land CAP not only didn't pay off, but these planes could have been used to make the Yorktown a coasting wreck if he had sent all his NAC and LAC to destroy it.

Example 3b: To continue with this example, let's presume 12 NAC and 8 LAC are sent by the Japanese on a naval bombing mission into Noumea targeting the Yorktown with no CAP. The allied player still tries to protect the Yorktown with 5 NAC and 5 LAC. Using the above example's same die rolls, 12 NAC and 8 LAC fire air superiority and shift down to the 90 to 99 chart with a '2' result which inflicts 9 eliminated and 8 abort which with the Japanese targeting NAC would result in 5 NAC eliminated and 4 LAC eliminated with one LAC aborting. The return fire of 50 would result with the allied player targeting LAC would result in 3 LAC eliminated and 4 LAC aborted. This would result in 12 NAC and 1 LAC continuing to the target. The allied player with 48 flak* rolls a '2' still targeting the LAC which would result in the last LAC being destroyed along with 3 NAC and an additional two NAC being aborted. The Japanese bombing force has been whittled down to 7 NAC which proceed to target with a bombing strength of 49. This puts the bombing force on the 24 to 1 table for air-to-surface combat. A '4' is rolled putting the Japanese player on the '1' column for damage. The Japanese player does not miss, however, and rolls a '1 which puts 10 weeks damage on CV-5 (Yorktown).

* the flak number is the same as above.

Concentration on one target pays. Part of the psychology of the game is assessing how aggressive or conservative your opponent plays.

So far, I like what I am seeing with this rule adjustment.

Example 3c:

Mutual Strikes are not a pretty thing. Let's say the CV Yorktown can take its chances, and the Allied player launches every plane he has at the Japanese carriers for a total of 15 NAC and 5 LAC. The Japanese player does the same in regard to his carriers feeling the gutless Allies wouldn't dare risk a mutual strike and sends 16 NAC and 8 LAC to turn the Yorktown into razor blades. In this case there are no air-to-air combats.

10 Allied NAC target CV-3; 5 Allied NAC and 5 Allied LAC target CV-4. Flak fire for both groups is on the 20 to 29 table. For the 10 NAC, a flak result of '2' means 3 abort and 1 eliminated. 6 NAC proceed to target and get a result of '20' weeks damage which is a poor result considering they had 33 to 1 odds.

The hapless LAC targeting CV-4 also receive a flak result of 3 aborts and 1 eliminated. The surviving unit immediately gets a no result on the 1-1/5-1 chart. The remaining 5 NAC get a 1 abort and 1 eliminated result on their flak roll, and obtain a 16 to 1 attempt on chart 4, but they only receive a chance on the 1 column on chart 5 and also get a no result. The Shokaku survives intact.

The Yorktown is not so lucky and receives 5 weeks damage from 3 Japanese LAC that attacked at 21 to 1 after their group had received 3 aborts and 2 eliminated from flak. Then the 16 NAC came, and got the same flak result with 11 planes surviving for a 77 to 2 (38:1) attack and inflicted 40 more weeks damage on table 7; the total of 45 weeks damage sinks the Yorktown.

Of course the Japanese did not need to enter the Noumea hex to launch this strike, and could have easily done it from hex 831 which would have been outside of the Enterprise's range.

Example 3d:

A cautious Japanese Admiral smells a trap, and decides the Yorktown is bait. He deploys his entire 16 NAC as CAP, and sends only his 8 LAC from Espirutu Santo to bomb the Yorktown. A daring US admiral sends all of his NAC (15) to sink a Japanese carrier while hoping that 5 LAC might make a difference in stopping a Japanese raid on Noumea.

In the naval Cap battle over Noumea, the Japanese deal a telling blow on the US carrier aircraft by aborting 7 and eliminating 5. While the Allied player only returns 6 aborts and 3 eliminated to the Japanese NAC flying CAP; it should be noted the Allied player suffered a one shift left (60-69 column) as he was conducting a naval bombing mission while the Japanese on CAP fired at full strength (80 to 85 column). 3 Allied NAC survive the melee, but none reach their target as flak fire eliminates 1 more and aborts the rest.

In the Land CAP battle the Japanese 8 LAC, shifting one left to the 30 to 39 table, destroy 2 and abort 2 Allied LAC who return fire on the 25 to 30 table but only manage to shoot down 1 and abort 1 Japanese LAC. The 6 LAC that survive undergo flak fire which is more effective by aborting 3 and eliminating 1 LAC. 2 Japanese LAC proceed to target and have a total of 28 to 2 on the Yorktown which is reduced to 14 to 1. The Japanese get a chance on the 1 column on table 5 and come through with 5 weeks damage on the Yorktown which is now out of action.

In this situation, the prudent course for the Allied player is to run.

Other ideas:

2. All air units that abort in an air-to-air combat must return to the closest base from where the air-to-air combat occured, if they are determined to be on a land air superiority mission (less than 51% CAP). This might make them subject to strafing, and airbase bombardment.

3. Keep the Deluxe rules as is but air units that are determined to be on the air superiority mission do not get a one shift left but have their air-to-air strength halved (round down) which is then added to the CAP total if any.

4. Return to the original system, and do not use the air superiority rule. This would give air units on defensive ground support a 'free pass' however.


One of the things I love about the original rules is this game was made when wargamers had to use pencils, do their own arithmetic, and even scrounge for other stuff.

From page 2 of the original rules:

"Certain equipment is not provided in the USN game which is needed for various game functions. These are: one die (i.e., one-half of a set of dice); several pencils with erasers; approximately 40 pennies (or similar markers); and approximately 6 to 12 sheets of ruled paper."

(the pennies were to keep track of NAC strength in a group represented by a letter counter.)
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Matt Irsik
United States
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That definitely took some effort and yes, the paperwork is a major obstacle towards getting this to the table more often. I think an easy thing is to not have to write down the air units each turn and just use some sort of IGOUGO mechanism, which would save a lot of time. I use very small D6s to make fuel status on the various task forces, which saves time from writing it down each turn or tracking it by paper. There's a lot of things as you've suggested that could be done to improve things, but with so many games out on this subject I think the question needs to be asked if it's worth the trouble.
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Robert McCoy
South Korea
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Alternate air system mark 2-A
USN — Air superiority rule change.

This rule change would introduce a direct air-superiority mission into the air to air combat system at the cost of some extra complexity, but I believe would avoid the pitfalls of the USN deluxe system. It has a little added complexity, but this would not last as losses from attrition would mount up quickly in a contested hex and simplify players' options. This mission could easily be added to the original USN system. It is not suitable for solo play.

Add a new mission to the mission chart — Air superiority.

Profile — Air superiority is a hunter-killer fighter sweep and is a type of force projection. This mission may be performed over any hex, but its primary function in game terms is usually to establish air superiority over land hexes where CVs have limited utility. Air superiority may not be used at extended range and has a 3 hex range maximum. (note 1)

Only NAC and LAC may perform this mission.

Units assigned to this mission do not perform any bombing missions, nor may they combine their strength points with any other air group, even if this air group is friendly and is also performing an air superiority mission. Thus an air group from a hex may combine its strength points at the hex of origin and then proceeds to its target hex. NAC and LAC be formed into one group for this purpose. In the target hex it operates completely independently from all other friendly air groups.

If more than one friendly air group enters a target hex on an air superiority mission, the owning player must number them sequentially, 1, 2, 3, 4 etc. Each air group must have a range number assigned such as 0, 1, 2 or 3.

Air-to-air combat phase

Phase one:
All air groups on an air superiority mission fire once at all enemy planes (not groups) on an air superiority mission. Each group fires individually. Owning player extracts losses. Such firing is considered simultaneous.

Firing penalty: Air groups at a one hex range from their hex of origin shift one to the left when firing. Air groups at 2 hex range shift 2 to the left, air groups at 3 hex range shift 3 to the left; 3 hexes is the maximum for an Air superiority mission. Planes from a CV or friendly airbase in the same hex on this mission do not suffer a column shift to the left.

Phase Two:

Each surviving Air group on the Air superiority mission using their numbered sequence now fires at any and all enemy CAP and bombing mission air units in the hex . The defending CAP and bombers return fire at each such group in sequence — remember CAP and bombing units combine their air strength into one total while air groups on the Air superiority mission are still penalized for range and fire separately. Thus the first air group fires and is fired at with losses extracted before the second group fires and so on.

All surviving air units assigned to the air superiority mission are now finished their mission and return to base at the end of the Air phase.

Phase Three:

All remaining naval CAP may fire at enemy bombers as they execute their missions as per the normal rules of the original game: first LBAC, then LAC and finally NAC for air-naval attacks then Land CAP fires at air units assigned to land installation targets, and finally any air groups assigned to offensive or defensive ground support.

CAP does not fire on CAP when using these rules, nor do bombers fire on bombers . CV task force groups can still flex their muscle over coastal hexes. Air superiority can be projected inland without resorting to bogus missions or giving planes unrealistic capabilities such as bombing and 'indirect' CAP at the same time. LAC or NAC from a friendly airbase or CV in a hex can be assigned to air superiority over their own hex, but being on combat air patrol gives a better return in terms of firepower and protecting targets. In contrast the main function of the Air superiority mission is to destroy enemy aircraft, not protect friendly ground or naval targets which is an indirect benefit.

Optional: planes assigned to bombing missions fire at CAP with a one-shift to the left penalty.

Defensive ground support is still difficult to engage directly in combat but becomes exposed as local air power is reduced from repeated sorties. Putting a CV in the same hex and assigning its planes to air superiority is an effective way of neutralizing air units assigned to land targets but is not without risk. (note 2) Otherwise neutralizing enemy air bases in the target hex's vicinity is still a valid strategy and probably a more efficient use of resources.

Note 1: I am assuming the USN original rules with Love and Diffenderfer's spotting variant.
Note 2: If naval CAP is a separate mission then a drawback is this CV, having assigned its NAC to air superiority, will need protection from an air-naval strike or even a surface engagement, so one CV is probably not enough. What often makes more sense is a CV's NAC are assigned to naval CAP, and the surface fleet neutralizes the Air base.

Any comments on this idea are welcome as it is untested.

take care
Robert W McCoy
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