Ship Combat Question: Point Defense

[SSWarlock]

The corebook rules state that a gunner performing point defense can roll to engage missiles, with a -1 cumulative DM per missile previously engaged, until a roll is missed (see page 149).

Does the number of weapons in the turret being used affect the point defense rolls in some way? If so, how? If not, why not?

 

[Denalor]

My idea about that issue can be found here
http://www.mongoosepublishing.com/phpBB2/viewtopic.php?t=37563

 

[Rikki Tikki Traveller]

I don't think the intent was to make it per weapon, but per gunner. Whether the gunner is firing a single weapon multiple times or multiple weapons, the idea is to simulate the ability to shoot some of them down, but not necessarily all of them. Gunner skill (and luck) being the driving factors.

This works very well for small ships with only a couple of turrets, but for larger ships the rules from High Guard will probably have to be used.

 

[Patron Zero]

Likely not to be accepted as canon but I like the idea of an automated point defense system exclusive of a vessels primary offensive turrets or other related ordnance.

In my pre-Mongoose TU I allowed for a sort of defensive CIWS on smaller starships to supplement the classic Traveller one turret per 100 tons rules. Mind if the player characters invested in better software or upgrades to the actual point defense systems, the chances of an inbound missile (or torpedo) being intercepted increased accordingly. I had considered the inclusion of gunnery skills to possibly enhance said results but preferred to leave such to crewed weapon stations (or turrets) in 'traditional' combat.

And should point out referring to non-beam weapon CIWS, either gaus-coil guns or possibly vacuum operational 'Gatling' style cannons, neither system to give an undue edge to the defending vessel. Limited magazine capacity as well as possible mechanical failure simply worked in to keep a game balanced and playable. Again, if you go Yugo rather than Cadillac you take your chances on the outcome.

 

[lastbesthope]

Something like the weapons set up we see in the episode "Mutiny" of Space : Above and Beyond would be interesting.

LBH

 

[phavoc]

Today in order to hit a defended target, the attacker fires swarms of missiles in the hope that a few will get through to hit. So it's entirely reasonable to mount some sort of close-in weapon defense that fires as a last-ditch attempt to destroy the missile prior to impact.

But for the most part player skill won't come into play. The time between engagement and impact is just too small. It's an automated system and either it works, or it doesn't. It's gonna have a maximum number of targets it can engage in any round, and of course its going to have a firing arc issue with it.

Likely not to be accepted as canon but I like the idea of an automated point defense system exclusive of a vessels primary offensive turrets or other related ordnance.

In my pre-Mongoose TU I allowed for a sort of defensive CIWS on smaller starships to supplement the classic Traveller one turret per 100 tons rules. Mind if the player characters invested in better software or upgrades to the actual point defense systems, the chances of an inbound missile (or torpedo) being intercepted increased accordingly. I had considered the inclusion of gunnery skills to possibly enhance said results but preferred to leave such to crewed weapon stations (or turrets) in 'traditional' combat.

And should point out referring to non-beam weapon CIWS, either gaus-coil guns or possibly vacuum operational 'Gatling' style cannons, neither system to give an undue edge to the defending vessel. Limited magazine capacity as well as possible mechanical failure simply worked in to keep a game balanced and playable. Again, if you go Yugo rather than Cadillac you take your chances on the outcome.

 

[Patron Zero]

Today in order to hit a defended target, the attacker fires swarms of missiles in the hope that a few will get through to hit. So it's entirely reasonable to mount some sort of close-in weapon defense that fires as a last-ditch attempt to destroy the missile prior to impact.

But for the most part player skill won't come into play. The time between engagement and impact is just too small. It's an automated system and either it works, or it doesn't. It's gonna have a maximum number of targets it can engage in any round, and of course its going to have a firing arc issue with it.

I also think a CIWS could be defined as a very simple arrangement of limited range VLS missile tubes, think more glorified mortars or clustered shotguns that discharge dense clouds of solid shot or even bomblets.

I like the idea of a ship dispensing 'chaff' or even 'flares' much the way modern day fighter-bomber aircraft do to evade incoming missiles. That mirrored on a starship as part of the automated CIWS package of offensive-defensive ordnance systems should increase the chances of said inbound threats being neutralized at a 'safe' distance.

 

[starfleet]

Honestly I can't see flares or chaff being 'that' much use in space for ships beyond a few tons.. the reason is that unless your running perminant stealth on a larger ship it simply has:

A. a much larger metalic signiture then any chaff would.
B. a much larger heat signiture
C. A much larger power signiture


even using the basic missiles we have today, the bigger the target the harder it is to 'spoof' the target with just chaff and flares.

ECM I could see coming into it's own in the form of jamming the trackers, hitting the seekers with low power lasers is likely to burn out sensors as well..

Also why is point defense a last ditch effort, lets look a simular styles of universe from the Honorverse PDS - Star Fire etc. it's a layered defense which is something i think Traveller forgets.. Heck we even use a Layered defense in modern combat:

A. ECM attempts to spoof the missiles guidance luring them off target.
B. Anti Missile, Missile Systems are launched at the incoming missiles in an attempt to blow the missile up with another missile.
C. Phalax systems attempt to intercept the missile as it close's into final range.

in a space setting the first two as far as I can see would be the same (presuming you don't have a CAP to attempt to shoot down the missiles)

at which stage, laser systems along with any other system you have that is capable of intercepting missiles would attack that aren't tasked with attacking the enemy to begin with so you'd end up with:


CAP if avalible (fighters generally have more range then any other system)
ECM
Anti Missile, Missile Systems
Laser Systems
Gattling Systems
Repulser Systems (using CT's tech)

then if all else fails:
Nuclear Dampeners if the missile is Non-Conventional.

Even then the one thing I didn't/don't agree with on CT is that a Dampener would block all of a nukes explosive power.. a Nuke that hits near enough the hull will damage something through raw kinetic force (heat and speed).. the radiation might be turned away but the ships hull and armor are gonna take some damage from the explosion itself.

 

[Patron Zero]

Honestly I can't see flares or chaff being 'that' much use in space for ships beyond a few tons..

I was using a common term to refer to much more sophisticated counter-measures, chaff being some process (physical or technological) to 'cloud' the inbound missile's sensors and a flare being a device that would draw attention away from it's intended target.

And yes, speaking more of non-military vessels, more referring to merchant ships or other private enterprise-commercial venture starships or reasonable if not modest displacement.

 

[starfleet]

Patron, I'd just lump it into ECM for the most part.. or actually ECM + Drones would be another and btw I realized technically i'm "wrong" CT and the like does have layered defense for Missiles, lasers, repulsors then Dampeners.. but yeah.. commerical vessel i'd see it as say when you go into combat here so lets presume that you have a pirate he's targeted you and fired a missile or a missile salvo:

1. Commerical ECM (or if you have the contacts non-commerical) would kick in trying to electronically jam the seeker's guidance.
2. a drone of some sort (reusable if it's not blown up after some maintance), is jettersoned out and keeps station at a distance away putting out a lot of heat and radar signiture.
3. depending on your set up either counter missiles launch or lasers/gattlings (with the first you'd likely use them first then gattlings/lasers second)
4. the missile gets passed you pray your dampeners hold against the explosion if it's nuke and you don't get rad fried.

how i'd do it in game is that ECM = modifier to the attack roll say a +1,2,3 etc kinda like stealth..
drone = another modifier based on tech level of the drone a +1 at say 12 and a +2 at 15.

on the same stage I also would play it that missiles etc have tech level etc that help with the targetting.. say a TL 10 missile has a +0 a TL 12 -1, TL 13: -2 TL 15: -3 or something like that.

that way say some one with Turrent gunnery 3 Dex mod 0 fired at a ship with no DM for the ship other then this, TL 12 Missiles.. the ship being attacked has ECM 1, Drone TL 12

based on hitting straight 8 as the starting point that would be modified by:

8, -1 (Missiles tech level) = 7
7 - 3 (gunnery skill) = 4
4 + 1 (ECM 1) = 5
5 + 1 (drone tl 12) = 6

So if the gunner rolled a 6 or higher on the missile to hit then the missile is on target resolve the Laser etc like normal to try and stop it if he rolls 6 or lower then it missiles on a 4 or 5 the missile blows up near the drone taking it out, any lower it missiles explodes and the drones safe.. etc.

that's real rough but it's just an idea i had.