JTAS 5 - Cascading Hull Failure

[Linwood]

Looking for thoughts on the damage control article in JTAS 5, in particular the cascading hull failure rule. I like the concept but the rule seems a bit problematic - a ship with one Critical could suddenly find itself (on a very unlucky roll) with 1D/100 dton continuing Hull damage unless a damage control roll is made. Makes starship combat much more lethal.

For those who don’t have JTAS 5 (yet) the rule is this - whenever ship damage passes a 10% damage threshold the GM rolls 2D with DM+1 per Critical Hit taken so far. On 12+ the ship begins taking 1D/100 dton in Hull damage, continuing until the crew’s cumulative damage control results equals or exceeds the damage taken that round. I’m thinking this should be adjusted by ship construction (Fragile or Reinforced Hull) and the ship’s age, and that the 12+ threshold may be too low.

Thoughts?

 

[Anonymous]

The rule sounds like it adds some interest and urgency to dangerous situations, and may be a useful tool for GMs.

Do they explain how this damage occurs?

If you are not on fire (no air), and not manevering, in zero G, then there is no stress on the hull. Superdense molecular bonding hull computer got hit?

 

[AnotherDilbert]

Interesting, that makes crit-fishing a lot more interesting...

 

[Old School]

Linwood, at first glance I agree with your thoughts. Like the concept, but it is very severe. Making the threshold higher would also mean that ships with zero critical hits aren’t subject to this risk. I think that’s appropriate, especially given the rules that limit the weapons that can inflict a critical hit on larger ships. If you want to destroy a capital ship with small weapons, you’re going to have to do it the hard way, not just than get lucky with this roll.

 

[Linwood]

To Moppy’s question the article refers to this rule in the context of space combat, so it sounds like the stresses from combat maneuvers and weaknesses induced by previous critical hits are responsible for the cascade. (Which makes me wonder what happens if you try to enter jumpspace with a cascading failure in progress.)

I could also see a modifier based on hull material; seems reasonable that crystaliron or bonded superdense will resist this better. It might make sense to have a modifier based on Armor rating - 1/2 or 1/3 feels appropriate - with the provision that this modifier changes if the ship loses Armor.

It would really make combat more exciting and might be the answer to the “what does 0 Hull mean?” question. But like Old School i’m Not on board with a chance this can happen with no critical hits unless another factor is in play.

 

[AnotherDilbert]

... - whenever ship damage passes a 10% damage threshold the GM rolls 2D with DM+1 per Critical Hit taken so far. On 12+ the ship begins taking 1D/100 dton in Hull damage, continuing until the crew’s cumulative damage control results equals or exceeds the damage taken that round.

Note that this only happens when the ship takes 10% damage, so at the same time as it takes a sustained damage crit. It can never happen without a crit.

 

[MonkeyX]

I like this idea as sometimes there may be players that don’t have an active space combat station. Having a fire break out that needs extinguishing or something else happen adds to the overall fun

 

[Linwood]

... - whenever ship damage passes a 10% damage threshold the GM rolls 2D with DM+1 per Critical Hit taken so far. On 12+ the ship begins taking 1D/100 dton in Hull damage, continuing until the crew’s cumulative damage control results equals or exceeds the damage taken that round.

Note that this only happens when the ship takes 10% damage, so at the same time as it takes a sustained damage crit. It can never happen without a crit.

Yep. What bothers me though is that with that first hit adding a DM+1 to the check you have a 1 in 12 chance of a cascading hull failure. Seems a bit high for most ships.

But I do think it’s a great story idea. Just a little cautious about the implementation.

 

[AnotherDilbert]

Add in a few laser and it will happen sooner rather than later...

I haven't really considered the consequences of this, but ACSs will really hate light laser fighters.

 

[Linwood]

I was thinking about that last night. This will really suck for small craft, since one solid hit can often generate multiple criticals. And single-person craft won’t be able to do much in the way of damage control.

But maybe that’s appropriate - not to mention very cinematic.

And maybe we should be fitting single-person craft with some sort of escape pod?

Another thought - there was no mention of repair bots in the article. I assume they’d be able to perform damage control, although maybe at a penalty. Certainly they should be able to support damage control checks by the crew.

 

[Old School]

A cockpit that separates from the main craft is a good idea.

I think its appropriate that small craft are wrecked by one shot. If one shot from a beam laser can do meaningful damage to a 400 ton ship, it should wreck a 10 or 20 ton ship.

What I haven’t been able to satisfactorily house rule is armor for small craft. The RAW allow for a lot of armor on small craft using minimal space. Short of a full chart that assigns tonnage to armor vs. ship size I don’t have a solution.

 

[AndrewW]

A cockpit that separates from the main craft is a good idea.

There's the Detachable Bridge option.

 

[Linwood]

Does that work for small craft? (Because it’s late and I’m too tired to look it up for myself...)

 

[Old School]

Minimum detachable bridge size per the rules is 15 tons. But don’t let that stop you!

 

[Linwood]

CORRECTION - Went back and reread the article and the check has a DM+1 for every 10% in hull damage - which is less ugly than per critical. My bad!

However - the rule calls for a check every time a ship crosses a 10% damage threshold. As written the risk of a cascading hull failure occurring gets progressively worse as the ship accumulates hull damage. But the risk also depends on how quickly that occurs - a ship that takes 50% Hull damage has a substantially better chance of avoiding a cascading failure. The risk of a cascade in that case is just over 58% if I’m calculating things correctly. But if the ship accumulates damage more slowly, crossing each threshold one at a time, the risk of a cascade occurring by the time you cross the 50% damage threshold is around 86%.

Feels a bit too harsh....

 

[AndrewW]

Does that work for small craft? (Because it’s late and I’m too tired to look it up for myself...)

Small craft can have bridges so yes. As long as you have the tonnage (and budget) for it.

 

[Old School]

Per the rules the minimum size for a detachable bridge is 15 tons, but it doesn’t appear to be written with small craft in mind. Just house rule it. Its a good idea.

 

[Anonymous]

Do fighters in Traveller have pressurised cockpits? I haven't seen anything about it. Otherwise just climb out in the vac suit and take the emergency kit that contains a radio beacon and a compressed gas thruster.

 

[Old School]

Per High guard, cockpits have 24 hours of life support.

 

[Anonymous]

Per High guard, cockpits have 24 hours of life support.

I don't have the thing at hand right now - is at 24 hours of refills for a suit, or 24 hours of air for not a suit?