Convoy Disruption: 1941, 1942.2 & G40 Submarine economic warfare

Trying to develop a general Convoy Disruption Rule which emphasis Submarines economical warfare capacity.
Continuating from this thread:
Re: Reality wrecking destroyer rules need a revamp…
http://www.axisandallies.org/forums/index.php?topic=34169.msg1396183#msg1396183

@Black_Elk:

I favor the 1:1 unit pairing suggested here.

Also the suggestion to allow u boats to dive after the first round of combat. My friends and I always thought that the Destroyer really neutered subs when it was first introduced with that ability to hold the sub for the duration of combat. We used to really enjoy Classic and Revised rules that allowed submarines to wage some form of economic warfare. Usually in the form of a modified strat bombing or rocket mechanic (these always seemed the simplest and most effective way to make subs  useful outside of opening strike combat or fodder.) But we also used to use rules similar to how convoys are treated.  We’d do subs 2 spaces out from an IC and things of that sort. Then the new rules and price structure were introduced… I felt they were pretty successful in establishing DD as the fodder preference, but also made subs rather weaker despite the cost drop. Basically since aa50 retaining the sub as basically only valued in a combat role.

Convoy disruption was a good attempt, but again I wish this stuff would be introduced on a core board instead of just the advanced one like the 1940 maps.
Some kind of baseline economic role for the sub, paired off against destroyers 1:1.
Although the new cost at six is pretty damn cheap. Something to encourage wolf packing would be nice. But also a reason to fan out across the Atlantic.

To date I’ve never been truly satisfied with implementation of subs absent some HR to correct them. Going back to Classic they are always problematic. But also iconic, and thus necessary :)
It would be nice to get something functional and handle their interaction with destroyers, air, and production once and for all. I would definitely prefer a scheme that could work across multiple boards.

Here is my attempt to provide Submarine as a functional economic weapon without the need to actually put some “Convoy Disruption” sticker into specific SZs.

Let’s assume that we agree on a Destroyer and Submarine being both at 7 IPCs or 8 IPCs with the following values and capacities:
Submarine A3 D1 M2 C8, everything else as OOB.
Destroyer A2 D2 M2 C8, everything else as OOB.
Since the new Submarine’s unit attacking value is 3, it is easier to assume that any damage due to Submarines’ Convoy Disruption is based on a single roll of “3” or less, while all “4” or higher are considered a miss.

According to my perspective of simplified interactions, I prefer these units as follow:

SUBMARINES A3 D1 M2 Cost 7
Surprise Strike, (blocked when at least 1 Destroyer or Anti-Sub Vessel is present),
Submerge, instead of rolling for a Surprise Strike attack (blocked by ASV on a 1:1 basis for the first combat round only),
Stealth Movement: No Hostile Sea-Zone (except ASV can block Submarine Stealth movement on 1:1 basis),
Cannot hit airplanes,
Can be hit by planes, doesn’t require an Anti-Sub Vessel.
Re: Reality wrecking destroyer rules need a revamp…
http://www.axisandallies.org/forums/index.php?topic=34169.msg1372793#msg1372793

DESTROYER A2 D2 M2 Cost 7
Anti-Sub Vessel: each ASV blocks Surprise Strike capacity of all enemy’s Submarine units present.
Cancel Sub’s Submerge on 1 DD:1 Sub basis_for the first combat round only_
(When it occurs, defending Subs rolls a Defense @1 in the first round, and any surviving Subs can submerge at the beginning of the second combat round.)
Cancel Sub’s Stealth Movement on 1 DD: 1 Sub basis for Combat or Non Combat Move, all additional Sub units can perform a Stealth Movement as usual.

To be eligible to Convoy Disruption by Submarine unit against the other side, a given SZ must have adjacent territories value hold by the enemy of at least 3 IPCs or more.
Merchants Convoy can be damaged in a whole game round for up to the maximum TTs values of the SZ, if it worths 5 IPCs, then it is up to 5 IPCs, etc.
The maximum damage is also determined by the number of territory owned by the owning Power being Convoy Disrupted.
If only 3 IPCs out of 5 IPCs value are still held by the enemy, then damaged can not be more than 3 IPCs for the entire round of play.

However, if a given group of adjacent territories hold by the enemy is less than 3 IPCs, then Convoy Disruption is no more possible.
For example, if Germany held Egypt (2 IPCs) and Trans-Jordan (1 IPC), it will not be possible to Convoy raid UK in SZ SZ 34 (which is bordering Saudi Arabia). Because East Africa (1 IPC) and Persia (1 IPC) make only 2 IPCs left.

So, each Submarine can do as much as 3 IPCs damage in any SZ which is adjacent to enemy’s start up territories adding up at least 3 IPCs worth.
For a whole round of play, each disrupted convoy can’t lose more IPCs than the total IPC value of controlled territories or islands adjacent to the sea zones.
Said otherwise, maximum Convoy Disruption damage is per each game round and up to each controlled territories worth adjacent to the sea zones.

To determine this value, simply makes the sum of all IPCs values of Territories bordering the SZ and of Islands groups within the given SZ.

For examples, on 1942.2 Map:

Northern Sea SZ 3 worths 3 IPCs for Germany:
Norway (2 IPCs)
Finland (1 IPC)

Artic Sea SZ 4 worths 3 IPCs for Russia:
Karelia SSR (2 IPCs)
Archangel (1 IPC)

Baltic Sea SZ 5 worths 17 IPCs for Germany, and even 19 IPCs if Karelia is captured.
Norway (2 IPCs)
Finland (1 IPC)
Baltic States (2 IPCs)
Germany (10 IPCs)
Northwestern Europe (2 IPCs)

Karelia SSR (2 IPCs) Russian TT

SZ 6 worths 4 IPCs for Germany or 8 IPCs for UK:
Northwestern Europe (2 IPCs)
Norway (2 IPCs)

UK (8 IPCs)
If Norway is conquered by Allies, then Allied Submarines won’t be able to Convoy Disrupt Germany because there will be only 1 single TT at 2 IPCs.
It is the same for German’s Subs, they won’t be able to Convoy Raid the Allied owner’s since Norway is only a 2 IPCs TT.

SZ 7 worths 8 IPCs for UK.
UK (8 IPCs)

SZ 8 worth 8 IPCs from a German POV or 8 IPCs from UK POV.
Northwestern Europe (2 IPCs)
France (6 IPCs)

UK (8 IPCs)

SZ 10 worths 3 IPCs for UK.
Eastern Canada (3 IPCs)

Eastern USA Atlantic SZ 11 worths 20 IPCs.
Eastern USA (12 IPCs)
Central USA (6 IPCs)
Mexico USA (2 IPCs)

SZ 14 worths 8 IPCs for Germany, as long as it holds North African TTs.
France (6 IPCs)
Morocco (1 IPC)
Algeria (1 IPC)

SZ 15 worths 6 IPCs from a German POV, as long as it holds North African TTs.
Italy (3 IPCs)
Southern Europe (2 IPCs)
Libya (1 IPC)

Black Sea SZ 16 worths 4 IPCs for Germany or 4 IPCs from Russia POV:
Ukraine SSR (2 IPCs)
Bulgaria Romania (2 IPCs)

Caucasus (4 IPCs)

SZ 17 (which is bordering Egypt) worths 3 IPCs:
Egypt (2 IPCs)
Trans-Jordan (1 IPC)

Caribbean Atlantic SZ 18 worths 4 IPCs:
Mexico USA (2 IPCs)
Panama (1 IPC)
West Indies (1 IPC)

South Atlantic SZ 22 worths 3 IPCs for USA:
Brazil (3 IPCs)

SZ 23, SZ 24, SZ 27 South Atlantic on African Coast
Cannot be Convoy Raid since there is never more than 2 IPCs values as bordering Territories.

SZ 28 (South of Africa) worths 3 IPCs:
Union of South Africa (2 IPCs)
French Madagascar (1 IPC)

SZ 33 (South to SZ 34) worths 3 IPCs:
East Africa (1 IPC)
Rhodesia (1 IPC)
French Madagascar (1 IPC)

SZ 34 (which is bordering Saudi Arabia) worths 5 IPCs:
East Africa (1 IPC)
Egypt (2 IPCs)
trans-Jordan (1 IPC)
Persia (1 IPC)

SZ 35 (which is bordering India) worths 3 IPCs:
India (3 IPCs).

SZ 36 (which is east of SZ bordering India) worths 4 IPCs 3 IPCs for Japan:
Malaya (1 IPC)
French Indo-China Thailand (2 IPCs)

Burma (1 IPC) UK TT

In this specific SZ, Axis Submarine can not Convoy Raid UK because it is a single 1 IPC but Allies can do it against Japan for 3 IPCs.
If UK gets hold of FIC to reach 3 IPCs, then Japan can do Convoy Disruption on UK.

Western Japan Sea SZ 62 worths 12 IPCs, 11 for Japan.
Japan (8 IPCs)
Manchuria (3 IPCs)

Buryatia (1 IPC) Russia TT.
In this specific SZ, Japanese’s Submarine can not Convoy Raid Russia because it is a single 1 IPC but if Russia conquer Manchuria (3 IPCs), Japan could do it since Russia would get 4 IPCs in this SZ.

In a given round of play, there is two occasions to roll for Convoy Disruption:
1- When a Submarine is On Convoy Raiding and forfeit any attack against Naval units.
2- When a Submarine is On Station.

1- When a Submarine is On Convoy Raiding
Instead of attacking enemy’s naval units, a Submarine which doesn’t submerge during the combat phase can make a Convoy Raid instead at the end of Combat phase of the attacking player’s turn.
Submarine unit is allowed to attack Merchants Convoy, if didn’t make any other attack nor submerge in the SZ, and this imply there was no naval combat in the SZ raided during Combat Phase.

2- When a Submarine is On Station
As long as there is still at least 1 enemy’s Submarine unit of the owner’s of adjacent TTs into a given SZ, this Submarine is considered On Station.
At the end of the territories owner’s turn (on his Collect Income phase), an enemy’s Submarine Disrupts Convoy.
Such Convoy Disruption is mandatory and all players must enforce the rule and watch for every submarine unit illegible to roll for damage.

CONVOY RAID or CONVOY DISRUPTION DAMAGE:
Each Submarine roll 1D6, considering only 3 or less for damage, up to the maximum number of IPCs from all territories owned adjacent to the SZ for a given round of play.
The Disrupted player must pay immediately to the bank the given IPCs damage.

So, if 2 UK’s Submarines roll 5 IPCs damage into SZ6 at the end of Germany’s Income Phase, then when UK’s Combat phase will occur in the same round of play, Germany will suffer no more damage due to Convoy Disruption in this SZ, whether from UK or from USA, until the end of the actual round of play.
This means that Russia can still do a Convoy Raid against Norway and Northwestern Europe, because Russia begins a new game round.

With so much adjacent TTs to Baltic SZ and Mediterranean SZ, do you think this kind of Sub HR will be mostly detrimental toward Axis powers?
One reason: Germany is not a Sea-Power, to get ride of any Allied Subs (along France, for instance), Destroyer units must be built.
But this defensive naval investment was never a required purchase for Germany. This makes an additional cost pressure to protect Germans’ incomes.

Do you think this way of designating Convoy SZ is balanced?
Or is it an issue, especially France TT adjacent to SZ 8 or SZ 14, as Convoy Disruption was an issue against Italy in Global 40 (sometimes Italy can lost even up to 12 IPCs to such Convoy Disruption in SZ 97 of 1940 Europe Map)?

Due to this increase in Submarine economic warfare capacity, do you think each Destroyer should blocks Sub on a 1:1 basis in every combat round, so only outnumbering Submarines can submerge at the beginning of any combat round?

There is no such thing as Convoy Disruption for Submarines in 1942.2.

I tried to make a proposition from Black_Elk wishes.

It would better reenact the historical Atlantic and Pacific Subwarfare with it.

@Narvik:

So, what is wrong with the OOB rule ?

Maybe were you talking about the submarine combat values?
Here are the main posts from the thread which started everything:
@Baron:

I play-tested the ideas below:

SUBMARINES A3 D1 M2 Cost 7
Surprise Strike, (blocked when at least 1 Destroyer or Anti-Sub Vessel is present),
Submerge, instead of rolling for a Surprise Strike attack (blocked by ASV on a 1:1 basis for the first combat round only),
Stealth Movement: No Hostile Sea-Zone (except ASV can block Submarine Stealth movement on 1:1 basis),
Cannot hit airplanes,
Can be hit by planes, doesn’t require an Anti-Sub Vessel.
Re: Reality wrecking destroyer rules need a revamp…
http://www.axisandallies.org/forums/index.php?topic=34169.msg1372793#msg1372793

DESTROYER A2 D2 M2 Cost 7
Anti-Sub Vessel: each ASV blocks Surprise Strike capacity of all enemy’s Submarine units present.
Cancel Sub’s Submerge on 1 DD:1 Sub basis for the first combat round only
(When it occurs, defending Subs rolls a Defense @1 in the first round, and any surviving Subs can submerge at the beginning of the second combat round.)
Cancel Sub’s Stealth Movement on 1 DD: 1 Sub basis for Combat or Non Combat Move, all additional Sub units can perform a Stealth Movement as usual.

TRANSPORT A0 1Def@1 Maximum per TPs group M2 Cost 8, 1 hit
A transports group get a single defense roll @1/round along with defending warships
(for this single defense roll, friendly transports are all considered being part of the same defending player’s group),
and each transport unit can be taken individually as casualty. As long as their is still 1 TP remaining, it can roll this single defense @1.
Must be escorted by a warship when making an amphibious assault in an enemy’s Submarines infested SZ or Transports infested SZ, so to be able to ignore them/ or fight them with combat units.
Otherwise, Submarines and Transports may be ignored during Transport Combat Move or Non Combat Move.
http://www.axisandallies.org/forums/index.php?topic=34290.msg1373212#msg1373212

The Submarines in defensive combat situations always rise the question of taking them as casualties or not (since it has such a low defense @1 and unable to hit planes).
The option of submerging after first round (even when enemy’s Destroyers are present, as allowed according to the HR above, not OOB) is still a tough call.
It clearly leaves all tactical decisions to the player.
That is quite funnier than all Sub rules I tested before (and I tested numerous variations, believe me! :-D):
will you take the Sub unit as fodder or let your Destroyer taking the hit, which gives the opportunity to submerge and fight another day (on offense with a high @3)?

No complex rules with planes vs Subs either.

I can see it work, people. Submarines are not always taken as fodder instead of a friendly destroyer, letting Destroyer be the main sea fodder. And the main reason is that you don’t want to loose you more offensive efficient Sub units in a desperate combat.
Sometimes, it is a tough call: giving an additional combat round to your Battleship, so you can have one last chance to make a hit @4, or simply submerging the Subs (sacrificing your BB) knowing that there is an enemy Battleship which will be without escorting DD and very vulnerable to First Strike Shots when your Subs will be on offensive.

The overall units interaction is simpler while the Submarines have a much more offensive role, if you don’t use them as fodder (which are not cheaper than Destroyer, since they are at the same cost.)

You can easily play Defenseless TPs at 7 IPCs and both DDs and Subs at 8 IPCs, if you prefer.
You will still get the same simpler interactions between combat units (Subs, DDs, planes).
I forgot to mention that according to the HR above, owner choose the order of all casualties, including transports.  So all the tactical choices are in his hands.

@Baron:

Thanks guys for your reply,
I think I really find the solution and it was under our noses.
The issue about 6 IPCs Subs is that it shouldn’t be the fodder of the sea, but 8 IPCs Destroyer.
Larry Harris fixed this issue by requiring that planes need Destroyer to hit Submarines, so not bringing into combat a Destroyer will prevent the defender to use submarines as fodder against a massive Air attack.

Your 8-8-8 was part of the solution Toblerone77.
Destroyer is still A2 D2 M2 C8, 1 hit, block Submarine’s no hostile SZ and Surprise Strike on 1:1 basis
Transport is A0 D1 M2 C8, 1 hit (I prefer chosen last for historical, but the Classic transport is OK, from a game play perspective)

The real change is to make Submarine absolutely not interesting unit as fodder.
Here is the trick, I think:
Submarine A3 D1 M2 C8, 1 hit, Submerge, cannot hit plane, No Hostile Sea Zone, Surprise strike and the rest as OOB.
Need 1 DD to block 1 Sub’s Surprise Strike.
Works the same as yours Der Kuenstler, with KNP escape always possible during regular combat phase, except 1 thing:
planes can always hit submarines (DD not needed, but they can submerge before being attacked, if the Surprise Strike Phase is not blocked).

On offense, such Sub can be prefered over Destroyer A2 and even sometimes, Cruiser A3 and Fighter A3, simply because you will be able to directly hit Warships, even capital warships (the costlier units), with even a bonus by getting ride of enemy’s DDs and being able to retrieve Surprise Strike. So submarine would not be chose amongst the first fodders casualties.

At first glance Sub seems more powerful.
In fact, this Sub unit is weaker than the actual OOB Submarine with DK’s HR.
4 OOB Subs A2 D1 C6 = A8 D4 C24, 4 hits.
3 Subs A3 D1 C8 = A9 D3 C24, 3 hits.
4 Subs A2 OOB 57% vs 3 Subs A3  38% for 8 IPCs Subs, if both were attacking the others at her attack factor.

On offense, it is still a formidable weapon, but on defense and due to the similar cost with Destroyer, it will be a waste to sacrifice them as fodder since you can always Submerge (once the first regular attack has been done against them, in case when many DDs are attacking) to make a better use of them on the offense. Let them survive to fight another day!
Why would you keep them as fodder to pad your fleet on defense, since they are now vulnerable to plane but unable to hit them like DD can?

I think this new combat value and the same cost as Destroyer and the evasive Submerge will do the job by itself without the need to add a specific restriction on casualty picking as I suggested earlier.

The optimized choice of any owner’s will be clear. You can use Subs as fodder on defense, but it is at a huge tactical cost, since this more expensive Submarine is an offensive weapon, hitting as hard as a Cruiser on specific targets, such as BB, CV and Cruiser. That was the case OOB, but since it was the cheapest warships, it was clearly tantalizing to pick them as casualty.

What do you think of this?
Isn’t that simpler?
No special rule for plane.
No unlimited blocker capacity for DD, keeping 1:1 against Surprise strike and no hostile SZ only.
A Submerge capacity which is not block but only delayed until the regular combat phase, which still imply that Planes needs to bring X number of Destroyers to prevent X number of Subs from submerging during their Surprise Strike phase.

Do you see why it was mostly right under our nose? :wink:

Do you think there is enough money on the 1942.2 board to be playable and not a plague on overall economy?

@Black_Elk:

But that precedent has been established with global.
Perhaps if you wanted to explore a less potent convoy disruption, the subs “on station” might only hit at a 1, or perhaps auto damage at 1 to match their defense value, the way you have the raid matching the attack value? This would be more of a token or novelty phenomenon, but might prevent the sort of disruption spam you see against Italy in G40.

The 1 hit auto damage can be interesting. It is, after all, the average results of 1+2+3+0+0+0= 6 out of 6 = 1 IPC.
I was inspired by G40 which gives to roll 2D6 for Convoy Disruption.
The difference is that I split the rolls to increase the opportunity for Submarine to do it before being sunk.
In a complete table turn, a single sub unit cannot do more damage than her G40 counter-part.

@Black_Elk:

Well, if the gameplay was enjoyable, I wouldn’t have any issue including some kind of simple repeating income bonus to facilitate a more dynamic submarine economic warfare situation.

Would be interesting to see how the starting submarines might be used during the first round, **if the player elected to use them for raids rather than combats.

The ability to bleed IPCs directly from the enemy can be very potent, especially if this can effect their starting cash. Thinking mainly of the UK.**

True. I didn’t think about it. It opens a completely different strategy.
One or two German’s Subs can try an opening raid.

Russian Sub will certainly make it against Finland-Norway Sz.

Doing Sub economic warfare in combination with Strategic bombing raid can now becomes a way to strangle an opponent.

@Black_Elk:

On the other hand, if disruption is restricted to subs only (no other ships), and you already have an increased cost for those, it might not be as huge an issue. Allowing air to hit subs would be helpful too, for helping to avoid the convoy disruption conundrum of G40.
:-D

The actual rules suggested still imply that a Destroyer is needed to prevent a Sub to submerge (on a 1:1 basis) before airplanes can make an attack roll.

I can’t figure a simple way to allow planes to hit submarines before they submerge without coming back to Revised Sub rules in which planes were Subs doom.

@Baron:

@Black_Elk:

But that precedent has been established with global.
Perhaps if you wanted to explore a less potent convoy disruption, the subs “on station” might only hit at a 1, or perhaps auto damage at 1 to match their defense value, the way you have the raid matching the attack value? This would be more of a token or novelty phenomenon, but might prevent the sort of disruption spam you see against Italy in G40.

The 1 hit auto damage can be interesting. It is, after all, the average results of 1+2+3+0+0+0= 6 out of 6 = 1 IPC.
I was inspired by G40 which gives to roll 2D6 for Convoy Disruption.
The difference is that I split the rolls to increase the opportunity for Submarine to do it before being sunk.
In a complete table turn, a single sub unit cannot do more damage than her G40 counter-part.

So, you believe it is better if the damage are following the Subs combat values: Attack 3 / Defense 1.

CONVOY RAID DAMAGE:
Each Submarine roll 1D6, considering only 3 or less for damage, up to the maximum number of IPCs from all territories owned adjacent to the SZ for a given round of play.

or CONVOY DISRUPTION DAMAGE:
Each individual Submarine On Station in a given SZ inflict 1 IPC damage, up to the maximum number of IPCs from all territories owned adjacent to the SZ for a given round of play.

In both case, the Disrupted player must pay immediately to the bank the given IPCs damage.

If you have a better way of formulating this HR, I will accept it gladly.

I can see the merits of this 1-3 on D6 roll for damage / 1 IPC auto-damage.
The first Convoy Disruption occurs during a Combat phase where there is already some dices tossing.

The second Convoy Disruption occurs during the Collect Income phase of the enemy player.
Collect Income phase have no such dice rolling.
So it is faster to simply count how many Submarines are On Station and to substract IPCs accordingly.

@thespaceman:

Hi all. Great discussion so far. I have always thought that there should be a sub war built into the game.  Here are a few thoughts.

First. The problem with planes. Historically planes were the nemesis of subs in The Atlantic. Closing the Air gap really was the end of the sub free for all. Asw planes were the liberators welling tons catalina etc not spitfires and hurricanes

Proposal:
1.only bombers can complete asw missions. Fighters do not have range or equipment for asw.
2. When on asw range of planes is reduced by 2.

Is the 1:1 rule to big a drop for the destroyers. A few destroyers would often guard an entire convoy against the wolf packs.
Proposal:
Destroyers remove the surprise strike at 2 subs per destroyer. This would give the destroyer a bit bigger bite.
Submerge.subs should never lose the submerge ability. It is the sub captains choice to attack or withdraw.

Fighters (F4F wildcat) and TcBs (TBF Avenger) were used against Subs in ASW but they were aboard Carriers, mostly escort carriers.
So in fact, Fgs attacking Sub from Island have a lot less range than Fgs aboard carriers. If you move the Carrier, you can move 2 spaces while Fgs go 3 space and came back 1 behind to deck on Carrier.

So, there is already in-built game restriction such as you suggested.

Within my HR, Sub is at the same cost as Destroyers and 1 DDs blocks all Subs First Strike, for simplicity.
Sub gets A3 D1 M2 while DD gets A2 D2 M2.

The 1:1 blocker is only for Stealth Move and Submerge.

The attack value of Subs is already better than DDs, no need to give an additional First Strike against DDs.

Thanks Thespaceman,
You gave me an idea to solve the German cunundrum when being Raided.
This country could find it hard and expensive to sunk subs.

Here is the idea: StBs get a special ASW attack @1.
It allows to strike Subs before they Submerge.
This occurs when StBs are attacking a SZ infested by Subs only.
Otherwise, a regular attack @4 is used.

So this gives StB a small chance to sink Sub. 1 shot  before submerge.
So it becomes possible to strike Subs without buying a Destroyer.
Of course, DD is far better but now you can do something against Convoy Disruption if you cannot invest in warships.

It can work as a Catalina or a Condor.

@Black_Elk:

I like this approach, because the mechanic is straightforward. I think I favor Convoy Raids over convoy disruption, because it still strikes me as a little strange allowing the enemy to make a form attack when it’s not their turn. But that precedent has been established with global.

Perhaps if you wanted to explore a less potent convoy disruption, the subs “on station” might only hit at a 1, or perhaps auto damage at 1 to match their defense value, the way you have the raid matching the attack value? This would be more of a token or novelty phenomenon, but might prevent the sort of disruption spam you see against Italy in G40.

On the other hand, if disruption is restricted to subs only (no other ships), and you already have an increased cost for those, it might not be as huge an issue. Allowing air to hit subs would be helpful too, for helping to avoid the convoy disruption conundrum of G40. :-D

I think I better understand why Der Kuenstler and you prefer a Convoy Raid which occurs during player’s turn combat phase.
The G40 Convoy rule are giving Warships some kind of “double dip” actions, unlike SBR or Shorebombardment which imply a choice:
you can SBR or a regular attack, you can Shore bombard or kill the poor enemy’s transport in the SZ but not both.

To the contrary, G40 Convoy Disruption makes for a regular attack in the SZ then, waiting till the enemy’s Collect Income phase, you can roll for damage according to the number of warships which still survived in the SZ.

This is probably one of the reason it affects Italy so much after Taranto raid. Italy lost all his big warships and if counter-strike goes sour, the Convoy Disruption is plaguing this Axis power.

I understand that G40 rules were made that way to simplify the calculations and bookkeeping about the maximum IPCs lost by multiple Raids from more than 1 enemy’s powers, for instance UK subs and US subs could do it against Italy, eventually. It becomes simpler to wait for Italy’s Income Phase to know the total amount of damage and to compare to the maximum allowed.

Here is my solution to solve both: 1- attack on player’s turn (no double-dipping effect) and 2-keep record straight (no immediate plunder on IPCs already owned by player but still waiting Income Phase to apply damage).

1- All warships can do Convoy Disruption, including planes which have room to land on a Carrier. No extra Fgs or TcBs can do it, neither StBs.
2- The damage results for all warships are following their attack factor or less:
Submarines Attack @2 (or Attack @3 if playing with Super Subs Tech, or with my HR Subs A3 D1 Cost 7 or 8 IPCs)
Destroyer Attack @2
Cruiser Attack @3
Battleship Attack @4
Carrier Attack @0 (But planes which can land on Carrier do damage)
Fighter Attack @3
TcB Attack @3 or 4 (if paired to Fg)

3- During combat phase, a player can Convoy Raid an empty SZ or a SZ which have only Transports or Submarines.
Said otherwise, if any enemy’s surface warships is in the SZ, there is no Convoy Disruption, only regular combat.
(Warships are actively protecting the merchant’s ships. That’s the way to rationalize this, IMO.)
This also imply it cannot make a regular attack on Subs and/or Transport and a Convoy Raid, it is one or the other, not both.
(Same rule as with Shore Bombardment applied for Convoy Raid.)

4- When rolling for damage, you only consider the lower results which would make for a hit in regular combat.
For example, Cruiser do damage on a 3 or less: 1 is 1 IPC, 2 is 2 IPCs, 3 is 3 IPCs, 4-5-6 make no damage.
Subs do it on a 2 or less: 1 is 1 IPC, 2 is 2 IPCs, 3-4-5-6 make no damage.

5- Once all damaged are calculated, you place in SZ a number of Attacker Country Marker equal to the amount of IPCs damage.
Example, 3 US Destroyers get 1,2,3. It means 3 IPCs damage.
So you put in the SZ 3 US markers.

6- When it is the enemy’s Collect Income Phase, you substract from his IPCs income the number of his Enemy’s Control Marker in the SZ Convoy Raided up to the maximum allowed for this SZ.

7- I would give a Special Convoy Disruption for Subs, each enemy’s Submarine still present in the SZ during player’s Collect Income Phase, makes 2 IPCs additional damage, up to the maximum allowed in this SZ.

That way the OOB 2D3 Convoy damage rolls for Subs can be taken somehow into account without too much complexification.

What do you think everyone of this change for G40 Convoy Disruption rules?