Art of Sub Warfare

I've ran some tests on how the PROMOTION_SEE_INVISIBLE_SUBMARINE works:
CiV 1.0.0.621 (Default XML values)

View of the WorldBuilder Scenario


Conclusions
Any naval unit can see Submarines if they are in any adjacent hex.


Any land unit can see Submarines if they are in any adjacent hex.


Notice that when the land unit is not adjacent, the sub cannot be seen (also applied to naval units that don't have PROMOTION_SEE_INVISIBLE_SUBMARINE)


Units with PROMOTION_SEE_INVISIBLE_SUBMARINE can see subs up to their maximum sight radius (default for Destroyers is 5; Subs 2)


Suggestion #1
Remove PROMOTION_SEE_INVISIBLE_SUBMARINE from all units other than submarines. They will be able to detect subs out to their sight radius (default 2). All other units (land and naval) will need to be in an adjacent hex.

Suggestion #2
Remove all sight promotions from the Destroyer (I.e - PROMOTION_EXTRA_SIGHT_III). The destroyer will now detect subs at 2 hexes or less (controlled by PROMOTION_SEE_INVISIBLE_SUBMARINE). If you want them to see subs farther, add an entry in CIV5Units.XML under BaseSightRange and set it to whatever number you want them to see. Also, the sight promotion on the Caravel would need to be lost with upgrade.

Suggestion #3
Give the Subs PROMOTION_EXTRA_SIGHT_I allowing the subs to see 3 hexes and attack 3 hexes. Use this with suggestion #2 and Subs can see subs out to three hexes, Destroyers can see them at 2 hexes, all other units must be adjacent to the Sub to see it.

Once the Sub is seen, it remains seen until it moves again. This is why cities can see Subs when the subs are next to them (anything adjacent to a sub can see it)

At a minimum:
The PROMOTION_EXTRA_SIGHT_III should be removed from the destroyer.
PROMOTION_EXTRA_SIGHT_II (Caravel) should be lost with upgrade.
Adjacent Units should not be able to see the Sub if they don't have PROMOTION_SEE_INVISIBLE_SUBMARINE (especially non-DOMAIN_NAVAL units)
Units without PROMOTION_SEE_INVISIBLE_SUBMARINE should only be able to detect the sub when they try to enter its hex.
PROMOTION_SEE_INVISIBLE_SUBMARINE should allow exploration of rival territory without an open border agreement.

I also noticed that if you hold down the right mouse button and mouse over hexes in the ocean, the move indicator sometimes will display red, indicating an invalid move. You can then deduce that a submarine exists in that hex...

I disagree with some of your conclusions/fixes.

I think that a destroyer should be able to see subs within their full sight radius (or at least 3 hexes, same as another sub - which I agree should be able to see 3 hexes, not 2).

Other units should not be able to see subs at all, while only cities that can build subs themselves (i.e. are advanced enough) should be able to see subs in adjacent tiles.

As for deducing sub locations, I'm not sure what the answer to that would be. Other than allowing units of different civs to stack (obviously not gonna happen, nor should it), there is no real possible solution. Maybe the tile should not show red until you actually issue the command and then the ship just stops in the adjacent tile.

Thanks for investigating the exact rules though. The civilopedia is quite imprecise in civ5. Furstratingly so.

prodigitize said:

...I think that a destroyer should be able to see subs within their full sight radius (or at least 3 hexes, same as another sub - which I agree should be able to see 3 hexes, not 2)...

Click to expand...

Destroyers at a minimum can see five hexes (2 + 3 from PROMOTION_EXTRA_SIGHT_III) and up to 8+ with inherited/chosen promotions and social policies. Seems unbalanced in its current form, given that subs can only see two hexes by default.

Agreed. But that doesn't have much to do with subs.

Though a destroyer should be able to see further than a sub, I think it shouldn't be able to surpass the 6 hexes visible by fighters. Since social policies and wonders can add +2, I guess destroyers should only get a +2 extra sight and caravels and subs should only get +1 (but that gets lost when upgrading to destroyers).

I.e. Subs/Caravels get +1 sight, so can see 3 hexes away, potentially up to 5 hexes away.
Destroyers get +2 sight, so can see 4 hexes away, potentially up to 6 hexes away.

My other point is that detecting subs should only be possible with units equipped with such technology. That is destroyers and other subs. There is no way a caravel or a land unit should be able to see a sub, even in an adjacent tile. Cities should only be able to see then if they possess the required technology to build destroyers/subs, or else it means they don't have the technological means.

Mind you, these are more subjective and debatable points, not necessarily bugs.

prodigitize said:

Agreed. But that doesn't have much to do with subs...

Click to expand...

A destroyer with the ability to see subs out to their sight radius is the only reason I think it has to do with subs. I agree that destroyers should have the same sight radius as they do now only IF it were possible to limit how much they see below the surface. As it is now, and AFAIK it's unmoddable (without the source SDK), there is no way to limit sub-surface sight independently of surface sight.

The solution I propose is the best compromise possible with the current modding tools:

Remove PROMOTION_SEE_INVISIBLE_SUBMARINE from all units other than submarines. Subs will be able to detect subs out to their sight radius. All other units (land and naval) will need to be in an adjacent hex (currently not fixable).

Give the Subs PROMOTION_EXTRA_SIGHT_I allowing the subs to see 3 hexes.

With this configuration, destroyers keep their large surface sight, but lose the ability to detect subs more than one hex away. Subs gain the ability to see them from three. Hunting subs requires building subs yourself.

I have a mod on the hub that does this... search "easymoney" if you're interested. It plays and is balanced well, but comments are always welcome.

Mind you, these are more subjective and debatable points, not necessarily bugs

Click to expand...

Seeing subs in adjacent hexes without PROMOTION_SEE_INVISIBLE_SUBMARINE is a bug (or at the very least, not what the designer intended). If you except that conclusion, the rest will follow. If not, then you're correct, it's subjective. The only one I'd consider debatable is the destroyers sight radius and its effect on balance regarding the submarine. Also, naval damage is going up in the next patch, which means that the destroyers faster movement and larger sight radius will make its likely first strike against subs more damaging, thereby tipping the balance between the two further off kilter.

The sub and destroyer are the only no resource, modern naval units. Given the above, why would someone ever build a sub?

prodigitize said:

Since social policies and wonders can add +2, I guess destroyers should only get a +2 extra sight and caravels and subs should only get +1 (but that gets lost when upgrading to destroyers).

Click to expand...

Let Caravels keep their PROMOTION_EXTRA_SIGHT_II, but change Destroyer's PROMOTION_EXTRA_SIGHT_III to PROMOTION_EXTRA_SIGHT_II. That way Caravels upgraded to Destroyers don't get any extra sight (because they already have the same promotion).

Yeah, subs are clearly broken. I tink the solution would be to make an ASW promotion which gives destroyers the ability to see subs in a three hex radius. All other units should not be able to see a sub unless they stumble upon it.
The idea behind the promotion uis that it should only be available after a certain tech and you have to dedicate resources to make part of your destroyer fleet into ASW vessels.

Submarines must be visible in adjacent hexes, otherwise you wouldn't know why you can't move there, so I don't think it's a bug (but maybe they shouldn't be visible by land units).

The sight radius of various units can be adjusted a bit.

The "extra sight" promotions should be "lost with upgrade", the same applies to many other unit abilities. I don't really like the concept of units retaining their special abilities when upgraded to different types of units.

They need to fix the following:

• Land units and cities should not be able to see subs (unless they have PROMOTION_SEE_INVISIBLE_SUBMARINE)
  
• Sea units without PROMOTION_SEE_INVISIBLE_SUBMARINE should see subs in adjacent hexes ONLY when they try to move into the submarines hex. Other than that, the sub remains invisible.
  
• Sight below water should be configured independently of sight above water. Maybe add two different variables. This would allow large sight radius on the surface, but none or a low sight radius below the surface.

I personally think units without the capability to see subs should be able to move onto their tile. Otherwise it's very much a cheat (and a tedious one at that!) for the human player to be able to detect subs just by testing tiles.

Also, I believe subs should be invisible until they attack, then visible for a turn or two after that. The capability to always see them could be a sonar promotion unlocked when subs become available, and allows detection a few tiles away (independent of regular sight range).

Oh, and they shouldn't get the "bombardment" line of promotions, since that's literally pointless for a sub.

It's clear submarines and aircraft were not finished. Incorrect promotions, visible to land units, no combat card for aircraft (originally), and hellloooo 30-second attack animation for stealth bombers!

BomberEscort said:

A destroyer with the ability to see subs out to their sight radius is the only reason I think it has to do with subs. I agree that destroyers should have the same sight radius as they do now only IF it were possible to limit how much they see below the surface. As it is now, and AFAIK it's unmoddable (without the source SDK), there is no way to limit sub-surface sight independently of surface sight.

The solution I propose is the best compromise possible with the current modding tools:

Remove PROMOTION_SEE_INVISIBLE_SUBMARINE from all units other than submarines. Subs will be able to detect subs out to their sight radius. All other units (land and naval) will need to be in an adjacent hex (currently not fixable).

Give the Subs PROMOTION_EXTRA_SIGHT_I allowing the subs to see 3 hexes.

With this configuration, destroyers keep their large surface sight, but lose the ability to detect subs more than one hex away. Subs gain the ability to see them from three. Hunting subs requires building subs yourself.

I have a mod on the hub that does this... search "easymoney" if you're interested. It plays and is balanced well, but comments are always welcome.



Seeing subs in adjacent hexes without PROMOTION_SEE_INVISIBLE_SUBMARINE is a bug (or at the very least, not what the designer intended). If you except that conclusion, the rest will follow. If not, then you're correct, it's subjective. The only one I'd consider debatable is the destroyers sight radius and its effect on balance regarding the submarine. Also, naval damage is going up in the next patch, which means that the destroyers faster movement and larger sight radius will make its likely first strike against subs more damaging, thereby tipping the balance between the two further off kilter.

The sub and destroyer are the only no resource, modern naval units. Given the above, why would someone ever build a sub?

Click to expand...

Totally agree with these suggestions.
However,i m afriad that there is no reason then to build the destroyer if any ship to adcacent tile can see it.!
How can you make the sub or other unit to enter/explore rival teritorry without an open borders agreement?
But i have edited the xml so that sub and destroyer need iron in order to build.I think thats cheap,and easy to find.I m not sure however,if AI prefers to build units without resources needed.
I made this experiment with ZERO Fighter:I made it build-able by every civilization and at the same time i removed resources for it(it was oil).The results were stunningver 10 fighter zero squadrons attacked me!

makrisgialos said:

Totally agree with these suggestions.
However,i m afriad that there is no reason then to build the destroyer if any ship to adcacent tile can see it.!
How can you make the sub or other unit to enter/explore rival teritorry without an open borders agreement?
But i have edited the xml so that sub and destroyer need iron in order to build.I think thats cheap,and easy to find.I m not sure however,if AI prefers to build units without resources needed.
I made this experiment with ZERO Fighter:I made it build-able by every civilization and at the same time i removed resources for it(it was oil).The results were stunningver 10 fighter zero squadrons attacked me!

Click to expand...

The destroyer still has its normal sight radius and can be used as scouts, it remains the same destroyer as the default one except it can't see subs at more than 1 hex. Now, submarines are needed to counter submarines. You could remove some movement points on the sub to make up for this if you'd like (or add some to the destroyer).

You can't make them explore rival territory <HiddenNationality> is currently broken.

You just need one of the extra sight promotions since they all stack. The sub has two sight by default, adding PROMOTION_EXTRA_SIGHT_I makes it three. (adding PROMOTION_EXTRA_SIGHT_II on top of that would make it five, etc)

Thanks for your contribution, I agree with your suggestions. The invisibility of submarines is indeed quite useless at the moment.

it makes subs quite pointless.
a couple of destroyers is a lot better.
subs should be invisible to all units that don't have a sonar promotion and able to be stacked.

PawelS said:

Submarines must be visible in adjacent hexes, otherwise you wouldn't know why you can't move there, so I don't think it's a bug (but maybe they shouldn't be visible by land units).

Click to expand...

Land units can (by the time there are subs) embark so the same argument applies to them.

Land units seeing subs is a side effect of not requiring them to be transported on a boat, and not likely a bug

--------------

I think subs/destroyers/battleships are meant to R/P/S, and don't think it's unintended that a destroyer has a major advantage VS a sub.

Some additional thoughts:
Apart from the visibility problem mentioned above, I see another relevant issue: All units can (basically) attack a visible submarine. That should not be possible or at least be very restricted. Attacking a submarine should be reserved for few units only (maybe via a promotion).
(This maybe belongs to the suggestion-forum)

Changes made in 1.0.1.217 show me that this will not be changed and how subs function now will be they way they'll function into the foreseeable future. Firaxis/2K updated the help text of subs to include a blurb that they can be seen from adjacent tiles, it appears their intent is to leave it as it is...

Sight below water should be configured independently of sight above water. Maybe add two different variables. This would allow large sight radius on the surface, but none or a low sight radius below the surface. (Post #10)

Click to expand...

The suggestion mentioned above would probably solve this bug:

Easymoney, Thanks for trying to fix the submarine visibility issue. I downloaded your Submarine Mod V3 from the Mod browser. It said "Transfer Complete" however, I never get the message to "Install" it, nor does it show up in my ....Mods folder. I've downloaded/installed several dozen other mods and haven't run across this. Any idea of the problem or do you have a zip file I could download from someplace? Many Thanks - Jim