Armor Factors

[phavoc]

The rules allow for a small 50ton fighter to have the same armor factor as a 500,000 Dton dreadnought. That has always struck me as nonsense. Common sense tells us that this is impossible. And reality tells us that armor capability is more than just slapping more slabs on top of slabs. In reality armor is highly dependent upon both materials science and engineering. And smaller anything simply cannot take the same amount of energy applied to it. The rules acknowledge this in comparing starship weaponry vs. vehicle.

Armor has two issues related to it (for the most part, though materials make this a more complex discussion) - mass of the armor and then the protection offered by the armor. If you use the basic crystal iron armor, adding more gives you a better armor factor. However as navies discovered when they started adding armor (and to a lesser extent, it's true in vehicles), simply welding more iron and steel on top of the other armor it doesn't give you linear extra armor protection. To begin with, it's just too massive. But more importantly, unless you had the proper underlying hull structure to both mount the armor against AND to handle the impact of the shells, it would quickly fail. So the armor technology had to address how to add more protection factor, minimizing the amount needed, and how to put it all together so it could actually work. Traveller simplifies all this and just has an armor factor, which isn't a bad thing for a game system. But the game also allows a 50ton fighter to have the same armor level as a dreadnought... and that's just silly. If you simplify the design system then common sense says that you are going to need to assign maximum levels for craft based on their size. Small craft might be armor level 0-2, 100-1,000 ton might be 0-4, etc, all the way up to the max. It makes no sense to allow a small craft to have all the benefits of being tiny, super-agile, and armored as much as a dreadnought. That's just... silly. The more armor you add the more mass (which isn't considered) and more hull structure to make it work in combat. Which means small ships don't have enough space to devote to it and function. Of course players are going to min-max the hell out of their designs, but this is why you have to put some sort of framework around things to make them somewhat workable and still be playable. It's hella fun to mount weapons on every surface point and wipe out armada's.. but Traveller has never been a bulletstorm style gaming system.

How do others handle this in their sessions?

 

[Old School]

It hasnt been issue in our game, but no one’s tried to build a 10 or 20 ton craft with bonded superdense factor 14, either. Using RAW, any player designed small craft is going to have a beastly amount of armor.

Having the armor as a pure percentage of hull size is the issue. Its not much sacrifice for a small fighter to give 11.2% of its tonnage for 14 poonts of bonded superdense armor. Thats a huge sacrifice for a large ship, especially one that is Jump-4.

My suggested solution is to keep the percentages, but also have a minimum tonnage for each point of armor (this could vary between armor types) so those percentsges arent abused by smaller craft.

A key question is how do you want to play the game? Do you want fighters that routinely shrug off multiple simultaneuous missile hits (a common occurence at Armor 14).

I would allow a decent amount of armor on smaller (200-400 dton) starships, although probably not 13 or 14. I do like the concept of a hesvily armored small beast of a ship that can defeat larger, less armored or unarmored opponents. The more you lower maximum armor by size, the more you emphasize the advantage of size in the mechanic.

 

[DickTurpin]

There is more to armor's effectiveness than sheer mass. There is also it's shape and slope. Using a simple example of a sphere, the only spot where the armor is restricted to its base thickness is the point directly in line with the weapon attacking it. As a shot strays further from this "direct hit" area the armor's effective thickness increases at the same time the chance of a shot skipping off rather than penetrating increases. See https://panzerworld.com/relative-armor-thickness.

If two spherical ships (one a 10 ton fighter and one a 500,000 ton dreadnaught) are compared, it is obvious that the attack angle changes far more quickly on the smaller ship. This rapid angle change grants the fighter a much greater effective armor rating than the dreadnaught, even if the actual armor thickness is identical. As a result, the fighter does not actually require the same thickness of armor to gain the same level of protection.

I addition, starship armor essentially IS the hull, it is not just bolted on after construction. The required structure is automatically included during the design process.

Taking these two factors into consideration, as well as desiring a game that does not require an advanced engineering degree to play, I have no problem using the rules as written.

 

[phavoc]

There is more to armor's effectiveness than sheer mass. There is also it's shape and slope. Using a simple example of a sphere, the only spot where the armor is restricted to its base thickness is the point directly in line with the weapon attacking it. As a shot strays further from this "direct hit" area the armor's effective thickness increases at the same time the chance of a shot skipping off rather than penetrating increases. See https://panzerworld.com/relative-armor-thickness.

If two spherical ships (one a 10 ton fighter and one a 500,000 ton dreadnaught) are compared, it is obvious that the attack angle changes far more quickly on the smaller ship. This rapid angle change grants the fighter a much greater effective armor rating than the dreadnaught, even if the actual armor thickness is identical. As a result, the fighter does not actually require the same thickness of armor to gain the same level of protection.

I addition, starship armor essentially IS the hull, it is not just bolted on after construction. The required structure is automatically included during the design process.

Taking these two factors into consideration, as well as desiring a game that does not require an advanced engineering degree to play, I have no problem using the rules as written.

That only applies to a projectile. Energy wouldn't be reflected the same way. Yes, the T-34 angle made a huge difference for cannons of the age - but even the vaunted T-34 was killed by an 88mm hitting the frontal plate. Only when you had smaller, less energetic rounds would it make a difference. And today, with APFSDS, or HEAT rounds specifically designed to address those sorts of things it's much less of an issue than it used to be.

It also doesn't take into account that the same projectile hitting the armor has to have the proper underlying superstructure to transfer the energy without buckling the armor. And that works differently the more armor you have.

Size makes a difference too. 10 tons vs 500,000 tons means the slope on the larger ship is essentially a flat surface. Only a smaller ship would be able to have an actual angle. And even then, the amount of energy transferred from the projectile is going to affect the smaller mass much more significantly than the larger one. The larger it is the more it can simply absorb. The smaller it is the more effect the energy being absorbed will have on the craft.

 

[Annatar Giftbringer]

I can see how it might become a problem, with fighters unable to hurt each other, and ships needing fusion barbettes as AAA...

This could create interesting situations, where two opposing swarms of heavy fighters might avoid each other and going directly for enemy capital ships, since they can’t hurt each other.

One way to avoid immortal small craft might be to try a version of the capital ship armour system instead? That’s what I’ve been intending to do, should it become a problem for me.

In capital ship battle mode (high guard, p.86 and onwards) each point of armour gives 3% damage reduction, so a maxed out armour 15 fighter would reduce incoming damage with 45% rather than ignoring all damage lower than 15.

Of course, in capital ship mode, damage works differently too, so perhaps 3% might now work when using regular ship scale damage, but the exact numbers can be tweaked until it feels right.

 

[AnotherDilbert]

Why would a 20 Dt small craft not be able to have as much armour as a 10 Dt grav tank?

Yes, it's a simplification that battleships are limited to the same armour as grav tanks and small craft. But allowing battleships a lot more armour would wreck the combat system.

If you want a more detailed handling of armour there is always TNE and FFS.


Isn't it about there that these discussions generally lead?

 

[Annatar Giftbringer]

Why would a 20 Dt small craft not be able to have as much armour as a 10 Dt grav tank?

Yes, it's a simplification that battleships are limited to the same armour as grav tanks and small craft. But allowing battleships a lot more armour would wreck the combat system.

If you want a more detailed handling of armour there is always TNE and FFS.


Isn't it about there that these discussions generally lead?

Good points! Keeping it simple is part of the Traveller charm, and as mentioned above, capital ship combat can be used if one wants to give everyone a chance to hurt each other.

 

[AnotherDilbert]

Note that laser turrets have no problem killing small small-craft with a single hit, since they have so few Hull points. Heavy armour is needed to give them any chance of surviving being shot at, and triple pulse lasers will penetrate even armour 15 depressingly often.

 

[Annatar Giftbringer]

Note that laser turrets have no problem killing small small-craft with a single hit, since they have so few Hull points. Heavy armour is needed to give them any chance of surviving being shot at, and triple pulse lasers will penetrate even armour 15 depressingly often.

True, triple turrets will get through, so perhaps
Fusion barbettes aren’t necessary for AA and large ships will be alright (at least the ones with pulse lasers..) that only leaves fighters having trouble hurting other fighters.

 

[AnotherDilbert]

... that only leaves fighters having trouble hurting other fighters.

Even heavily armoured light fighters will inflict damage to each other occasionally, and with 60 dogfighting attack for each ship attack they will kill each other within a round or so.

Example: Two identical light fighters in dogfight:
Attack: +4[gunner] +3[FireCtrl] +2[pulse] +1[aid gunner] +2[dogfight] -4[dodge] = +8 to attack:

Attack roll on horizontal axis, damage roll on vertical axis, all possible results enumerated.

So they do an average of 0.93 damage with a 32% chance of a crit. Since even 2-3 damage leads to a killed fighter with crit ripple, they will kill each other in just a few dogfighting rounds.


With a boon from a sensor lock:

The likelihood of high attack roll increase significantly, leading to average damage 1.5 and 50% crit.


We can even use a called shot to inflict a Hull crit, almost guaranteeing a kill with crit ripple:

Even with the negative DM for called shot we have a 26% crit chance, which is basically a 26% kill chance.


With these damage levels even heavy fighters with max armour and only a single pulse laser will kill each other within a single space combat round.


Note that even a single beam laser has a decent chance of inflicting damage:

 

[AnotherDilbert]

Also note that with even a little less armour, damage (and kill chance) is much higher.

E.g. with armour 10:

We have well over 50% chance to kill a light fighter with a single shot...

 

[AnotherDilbert]

And finally note that even with Armour 15 and Reflec for a total of Armour 18 vs laser:

A single pulse laser will do damage, but needs both a high attack roll and a high damage roll.

With a 10% chance of inflicting damage it will take 10-20 dogfighting rounds to kill a light fighter, but that is still much less than a single space combat round...

 

[Condottiere]

Depends on your tolerance for complexity.

Fire Fusion Steel had a go at a universal armour system; Tee Five permits composite armour.

You could also tweak the design to permit selective armouring around more vital ship components.

 

[phavoc]

Why would a 20 Dt small craft not be able to have as much armour as a 10 Dt grav tank?

Yes, it's a simplification that battleships are limited to the same armour as grav tanks and small craft. But allowing battleships a lot more armour would wreck the combat system.

If you want a more detailed handling of armour there is always TNE and FFS.

Isn't it about there that these discussions generally lead?

They shouldn't. If you've ever been in a tank you will notice there is a huge difference between that and a naval craft. They aren't exact analogues, so let's assume an M-1 tank vs small craft yacht. An M-1 is 32ft long, so let's say a 60ft yacht. Top speed of an M-1 is about 50Mph. For comparison we'll use a Hatteras 64 motor yacht (random Google find). It's top speed is 21Mph. The yacht has 2 cabins, 3 heads and berths. The M-1 seats 4.

These are two very different vehicles, but it illustrates the discussion about the cost of having lots of armor - space. So there's no real reason why a vehicle could not mount same levels of armor as a space vessel. I am actually looking for a simple method, but also one that recognizes common sense.

So I would offer to you the same question - why would a 50 Dt small craft be able to have as much armor as a 10,000 Dt cruiser?

 

[MongooseMatt]

I am actually looking for a simple method, but also one that recognizes common sense.

Referee fiat.There is no other way.

We are not looking to limit players or produce ships for a pure Third Imperium setting in High Guard (or any of the core books, for that matter). It has to be able to handle all kinds of ships from all kinds of universes with the minimum of pain. You might, for example, have a setting where there are no big ships and everything is done with fighters, so having the higher armour values might make sense there. Alternatively, you might decide that fighters should have paper thin armour and impose your own limitations when creating new designs.

This is all working as intended, as they say. Just don't let your players loose on the design engines without limitations. The building example in the VHB is probably the best that will happen and it could get a lot worse...

 

[AnotherDilbert]

They shouldn't. If you've ever been in a tank you will notice there is a huge difference between that and a naval craft.

Spacecraft are not watercraft, nor are they aircraft.

From the detailed design systems, such as MT and TNE, we know that grav tanks and spacecraft are built the same way with the same armour and other systems.

Since both are almost unconstrained by mass they can both mount very thick armour. Both space fighters and grav tanks are basically flying tanks.

So I would offer to you the same question - why would a 50 Dt small craft be able to have as much armor as a 10,000 Dt cruiser?

Agreed, that is a huge limitation of the system, but what would actually be better if the cruiser could mount Armour 100?

 

[phavoc]

Spacecraft are not watercraft, nor are they aircraft.

From the detailed design systems, such as MT and TNE, we know that grav tanks and spacecraft are built the same way with the same armour and other systems.

Since both are almost unconstrained by mass they can both mount very thick armour. Both space fighters and grav tanks are basically flying tanks.

No, they are not, but you are missing my point. A tank pays for all that armor by having very cramped conditions. You don't see that penalty on spacecraft. I was giving an illustration.

The issue I've been saying all along is that the system is broken, and has been, for quite some time. There is no magical aura about spacecraft that makes them able to reduce reality so you can say this hull a few inches thick is BETTER than the foot thick armor a tank would mount. That's silly. Armor is armor, weapons are weapons. As long as you can power a starship laser on a tank it should hit the same as a laser on a starship.

Even though the mass of a ship isn't factored in (thankfully), it doesn't give you a magic wand and say you can pile 40m of armor on the outside of a 10Dt craft and it still only displaces 10Dt. Displacement in reality is taking the volume based upon the external. So everything you add takes up INTERNAL space. Which means you can't cheat and add layers upon layers outside for free. The concept of turrets violates that rule of logic, but that's a different argument.

Agreed, that is a huge limitation of the system, but what would actually be better if the cruiser could mount Armour 100?

Striker tried to create a universal system, with I think, 1pt of starship armor being equivalent to 40pts of vehicle armor. But if mass means nothing, then armor is armor. And if that's the case, then yes, you'd have to increase the numbering scale to accomodate it.

I prefer the simpler armor scales because adding more numbers can complicate things more than they need to be. However my point remains - how can you equivalently armor a fighter to the same level as a battleship? That's indicative of a broken system.

 

[phavoc]

Referee fiat.There is no other way.

We are not looking to limit players or produce ships for a pure Third Imperium setting in High Guard (or any of the core books, for that matter). It has to be able to handle all kinds of ships from all kinds of universes with the minimum of pain. You might, for example, have a setting where there are no big ships and everything is done with fighters, so having the higher armour values might make sense there. Alternatively, you might decide that fighters should have paper thin armour and impose your own limitations when creating new designs.

This is all working as intended, as they say. Just don't let your players loose on the design engines without limitations. The building example in the VHB is probably the best that will happen and it could get a lot worse...

Hi Matt,

That's always a possibility and also a long-held rule for gaming.

My issue is that this is where we (the players) are looking to the game manual community to come up with these things for us. Obviously we could build entire systems using house rules, and I'm sure there are a few people out there who have. But I think most prefer to buy rather than build their game mechanics.

And your point about making a system to handle all kinds of variations is spot-on. But it also sidesteps the original question - how does something so tiny get the same level or protection as something 1,000x it's size?

 

[MongooseMatt]

And your point about making a system to handle all kinds of variations is spot-on. But it also sidesteps the original question - how does something so tiny get the same level or protection as something 1,000x it's size?

Well that depends on your setting - and you are absolutely within your rights to say it can't, and impose a limit (we put all kinds of limit on the 'official' 3I ships, such as a jump-6 max). This is perfectly normal. Or, you might say, the fighters in your setting use unobtanium in their armour, which cannot be done on larger ships because of expense - they get around the problem by using more of the normal stuff.

This is something that we, as designers, _really_ should not get into with a game like Traveller as anything we do will ultimate limit someone's campaign. We _can_ say that in our published universes, rules x, y, and z are imposed upon ship design (and there has been talk of doing a book that describes exactly that for the Third Imperium universe).

We have to strike a balance between definitions and flexibility. We get round this by saying you can do pretty much anything you want as the rules give you that much latitude, but you have to put a bit of work into your universe - however, if you don't want to do that, our published universe comes pre-packaged and ready to go.

This does mean that Traveller is trying to be two different things - but I think it pretty much works

 

[AnotherDilbert]

No, they are not, but you are missing my point. A tank pays for all that armor by having very cramped conditions. You don't see that penalty on spacecraft. I was giving an illustration.

I don't believe I'm missing the point.

Tanks and fighters are built the same way and use the same armour. Fighters are cramped too and generally do not have four men crews. Even light fighters are much larger than current tanks (~2 Dt?).

There is no magical aura about spacecraft that makes them able to reduce reality so you can say this hull a few inches thick is BETTER than the foot thick armor a tank would mount.

They both use the exactly same ~50 cm armour to get the same armour value (Space 15 / Vehicle 150).

Armour is not all that large but very heavy, the limiting factor is generally mass not space.

Even though the mass of a ship isn't factored in (thankfully), it doesn't give you a magic wand and say you can pile 40m of armor on the outside of a 10Dt craft and it still only displaces 10Dt.

No one uses 40 m of armour, only about 0.5 m max.

Striker tried to create a universal system, with I think, 1pt of starship armor being equivalent to 40pts of vehicle armor. But if mass means nothing, then armor is armor. And if that's the case, then yes, you'd have to increase the numbering scale to accomodate it.

Striker was vehicles only, MT combined HG and Striker to a single system, with some strange side effects.

I prefer the simpler armor scales because adding more numbers can complicate things more than they need to be.

The space system is anchored to the vehicle and personal system on the small side. Unless you want to rebuild the personal combat system too, not just the space combat system, you have to increase armour on large ships, not decrease armour on small ships.

However my point remains - how can you equivalently armor a fighter to the same level as a battleship? That's indicative of a broken system.

It's been done in TNE. Larger ships are immune to the puny weapons in fighters and ACS. I believe that wasn't popular...

But basically I agree that the system in TNE that was somewhat more realistic and considered mass was superior. It was also much more complicated, both the design system and the combat system.



It's not very difficult to make the armour system more thickness oriented. Just drop the TL limitations allowing craft to carry as much armour as they like, and halve the size of each point of armour for each ten times the size of the craft.

Size adjusted Armour volume = Armour volume × 0.5 ^ ( log₁₀( craft displacement ) - 1 )
So,
10 Dt craft use the normal volume,
100 Dt craft use half the normal volume,
1000 Dt craft use quarter the normal volume,
100000 Dt craft use sixteenth the normal volume,
etc.

This leads to cruisers with Armour 100 and battleships with Armour 200 or so.
And fighters will still have ridiculous armour since they don't have to accommodate all that jump fuel.
And you have to rebuild the entire combat system...