Point Defense

[Major B]

Question on MT vehicle designs -

What is the benefit of the higher-tech level point defense modules? While the power requirement decreases, weight, volume, and costs increase with each tech level.

If the tech difference between the firing system and the point defense module generated a DM then I could see a benefit to installing the higher tech systems. However, power is usually less of a problem than space for me so I'm inclined to go with lower tech level modules. I just want to be sure I'm not designing a weakness into my vehicles.

I'd appreciate any insight, especially if I'm missing something that is already covered in the rules.

Major B

 

[jec10]

In Ct/Striker the advanced PD fire control allows you to roll more dice against incoming rounds. No evidence of this in MegaT.

 

[jec10]

Major B,

hope you're still around. I dug out a (very) old post from Rob Dean on TML that tried to put back into MT some of the stuff from CT/Striker they left out by mistake in their cut-and-paste:

"POINT DEFENSE



One of the Striker artifacts left in the MT rules is the Point Defense
targetting system.



Basically, a point defense weapon could do one of three things: Shoot at
targets (like anything else), shoot at direct fire weapons like missiles,
as long as they were visible for long enough to track (the PD weapon had to
be able to see the last 150m of the trajectory, and you could support other
vehicles as well as your own), and shoot at incoming indirect fire. A tech
9 PD system gets 4 dice against indirect fire, plus two dice for each tech
level higher, so that TL10 gets 6, TLll gets 8 and so on. These dice are
modified by individual DMs of plus or minus the difference in tech levels.
Zero is the minimum. Thus, if your TL14 artillery fired at my TL9 PD system,
I'd roll 4 dice (at -5 each, meaning that only 6s would knock down a
projectile.) If my TL9 artillery fired back, your TL14 PD system would roll
14 dice (+5 each) for an average of 119 projectiles destroyed. Multiple
rocket launchers, which shoot everything at once, have an advantage against
PD systems due to overload--divide the hits by two. So, in the example given
above, you would knock down an average of 60 rockets, rather than 119.



Nothing to it...but they didn't bother putting it in MT, even though they left
in the PD fire control systems.



My additional recommendation would be to allow weapons with PD fire control
to fire at moving targets with no movement penalty, since they are designed
to destroy fast moving targets. I'd also limit the number of indirect fire
rounds that can be destroyed to the rate of fire of the weapon, which puts
a premium on things like rapid pulse plasma guns. A third recommendation
would be to not permit anti-indirect fire with a PD projectile gun. You still
might want PD fire control for a projectile weapon because of recommendation
one, however."

 

[Major B]

Jec10, thanks very much for digging that one up.

I've asked DonM to take a look and see if this is something to add to his MT errata compilation.

Major B

 

[DonM]

I agree that there's errata here, but what is it?

The errata could be "remove point defense completely", it could be "extensive rewrite of section incorporating Striker info", or it could be something else...

Any suggestions?

 

[aramis]

Incorporate addition of rules.

 

[jec10]

I agree that there's errata here, but what is it?

The errata could be "remove point defense completely", it could be "extensive rewrite of section incorporating Striker info", or it could be something else...

Any suggestions?

As you are aware, and as pointed out in the original post by Major B, the MT point defense stats make no sense as printed. As we know, the entire point defense rules section appears to have been forgotten. I concur that the simplest thing would be to remove the point defense references from the vehicle design system. I guess it depends on whether you think point defense weapons are a core part of Traveller military canon. I'd say, given that they appear in CT from LBB4 on, and in TNE, it would be a bit odd to have them not existing in MT. Hence I suggested Rob Dean's views back in the day. Incorporating them doesn't seem too egregious.

 

[DonM]

While I have a copy of Striker, I don't know the system all that well. How much of a cut and paste from Striker is needed, and can someone point me to the section in the Striker rules that we need?

And, if we are going to do that, do we need anything else from Striker in MT... If we're adding ONE thing, let's go over Striker now and see if the MT rules are dependent on any other "missing" pieces that need to be added from Striker.

 

[jec10]

Point Defense rules start on page 6 of CT/Striker Rule Book 2: Advanced Rules. The distillation by Rob Dean I posted earlier in this thread may actually be more useful for MT - given the differences in "turn" structure and length between the rulesets (which you'll remember in MT led to the famous wrong rating of mass driver weapons). Remember also that in CT/Striker 1cm=10metres. I'm not sure how you'll interpret a CT/Strker weapon's "effective range" for MT. I'd guess it is the maximum rangeband before attentuation starts to apply. So an autofire weapon with point defense fire control could engage indirect fire rounds falling as far out as the rangeband before attentuation starts to apply to reduce its penetration. The number of dice against indirect rounds is only going to apply in MT large scale combat (the rules in the referees companion) - for the normal MT combat system (in the players manual) you are just going to try to shoot down a single incoming indirect fire round (and I'd suggest the relevant CT/Striker section is Rule 36.B on page 7, even though that says it is for point defense against direct fire) because that is how indirect fire is incorporated.

 

[DonM]

Hmm... I'd like Aramis to weigh in on this -- he knows weapon details for MT far better than I, and I'd like his expertise on what could or should be used for MT errata on point defense on Striker. For that matter, I'd wager he's also pretty good at handling Striker, so if he looks at this thread again...

 

[aramis]

There's the rub: I've only played striker as striker a handful of times. I'm an AHL guy. And even then, I've not played EITHER striker nor AHL since 1990.

So, we hve PDFC knockign out multiple rounds in striker... where's my books... not handy... arrgh...

This is a simple case of the Striker mechanic looks portable enough.
It also appears skill-less.
Effective range is Routine Task, not pen-drop, IMO, but both happen the same in striker/ahl.

 

[Major B]

DonM,

I'm not able to address the entire problem, but here are a couple of suggestions:

Player's Manual page 68 - Fire Control - Add the following as the last sentence in the paragraph: "Vehicle mounted weapons with point defense targeting modules suffer no penalty when firing at moving targets."

Player's Manual page 69 - Following Direct Fire - Add another paragraph titled "Point Defense Fire: Direct Fire weapons equipped with a point defense targeting module can fire at incoming missiles, rockets, and CPR indirect fire. Incoming rounds must be visible by direct line-of-sight by the point defense system for at least 150 meters of their trajectory in order to be targeted." (need helpworking out the mechanics here)

 

[jec10]

These suggestions look good Major B. I'd modify the second slightly though. I think as written it should apply to "direct fire missiles, grenades and rockets". [so you can target RAM grenades and ATRL as suggested in Striker] Add "A marginal success on the task roll destroys one incoming round; if there is exceptional success (see page 71) each level by which the task roll is exceeded destroys another incoming round, the player firing the point defense weapon decides which incoming rounds are destroyed. Point defense weapons ignore the 'small target' difficulty level increase. Ground vehicles may not move if they are to perform point defense fire (grav vehicles are not restricted)"

Then add another section on page 73 for indirect fire: "Weapons with point defense fire control can engage incoming indirect fire rounds intended to land anywhere out to the range at which the difficulty for the point defense weapon to engage them would remain at most Routine. The procedure is the same as for point defense against direct fire."

[By using the last you see the value of having higher TL point defense fire control.]

 

[Major B]

So the advantage of succeeding tech levels in PD modules is the range of the 'umbrella' they provide?

This is good, but only gives an advantage at TL 14 where the range jumps from V Long to Distant, so there is no effective difference between a TL 9 and a TL 13 PD module.

Is there a way to apply the TL difference between the firing system and the PD system as a DM as you showed Striker does?

 

[Major B]

Thought more on this while I was on the Subway this morning - How about applying (TL minus 9) as a +DM to the roll so that any exceptional success resulting from the roll will knock down more incoming rounds. I think that is in keeping with your intent.

I think this works better than trying to cobble some opposed die roll and I don't see how the firing platforms TL will effect the difficulty of the PD fire except possibly in the case of a missile.

 

[jec10]

Thought more on this while I was on the Subway this morning - How about applying (TL minus 9) as a +DM to the roll so that any exceptional success resulting from the roll will knock down more incoming rounds. I think that is in keeping with your intent.

I think this works better than trying to cobble some opposed die roll and I don't see how the firing platforms TL will effect the difficulty of the PD fire except possibly in the case of a missile.

I think this sounds perfect!

The only way I could see the original CT/Striker 4D, 6D, etc being useable is in the large-scale combat in the Referee's Companion where indirect fire arrives en masse like in CT/Striker. In ordinary MT combat it doesn't.

 

[Major B]

Then here is a consolidation with some additions - check to see if I captured each piece correctly and that my additions make sense (it sounds confusing to me so call this a second draft and suggest clearer wording if you can):

Player's Manual page 68 - Fire Control - Add the following as the last sentence in the paragraph: "Vehicle mounted weapons with point defense targeting modules suffer no penalty when firing at moving targets."

Player's Manual page 69 - Following Direct Fire - Add another paragraph titled "Point Defense Fire: Direct Fire weapons equipped with a point defense targeting module can fire at incoming direct fire missiles, grenades, rockets, and indirect fire from mortars, howitzers, high-velocity guns, and mass drivers. Incoming rounds must be visible by direct line-of-sight by the point defense system for at least 150 meters of their trajectory in order to be targeted. The range at which a point defense system can engage is limited by the shorter of the weapons range or the range at which a fire controlled weapon can engage with routine difficulty (V. Long for TL 9-13, Dist. for TL 14+). Apply a +1 modifier to the roll for each tech level above 9 of the firing point defense targeting module (a TL10 module receives a +1, TL11 receieves +2, etc.). A marginal success on the task roll destroys one incoming round; if there is exceptional success (see page 71) each level by which the task roll is exceeded destroys another incoming round. The player firing the point defense weapon decides which incoming rounds are destroyed. Point defense weapons ignore the 'small target' difficulty level increase. Ground vehicles may not move if they are to perform point defense fire (grav vehicles are not restricted)."

Player's Manual page 73, add the following sub-paragraph at the end of the Indirect Fire section: "Weapons with point defense fire control can engage incoming indirect fire rounds targeted to land anywhere out to the range at which the difficulty for the point defense weapon to engage them would remain at most Routine. The procedure is the same as for point defense against direct fire (see page 69)."

 

[Scott Martin]

Doesn't MT have stabilization by TL? IIRC point defence could operate from a moving vehicle if it was appropriately stabilized (negative mods at low TL's) generally by TL-9 vehicles with stabilization could move at flank speed and fire (even Pt Def) and have no mods, whether Grav or ground

and given the ROF of most PD weapons, you probably want each additional level of success to destroy 2x as many rounds (so a +4 exceptional success should destroy 1+2+4+8+16 = up to 31 rounds)

This post is based on memories of Striker, which is what MT is based on, but not MT itself: Striker PD weapons could eat up a prodigious number of incoming rounds. Striker also differentiated some systems (like Multiple Rocket Launchers) which were designed to saturate point defence: if these are used, then PD is 50% as effective (so the above "31 rounds" would destroy 16 MRL rounds instead: always round in the defenders favor)

Scott Martin

 

[Major B]

MT has stabilization but it is only required for vehicles using tracks, legs, wheels, or air cushion for locomotion. The stab systems vary in volume from TL 6-10 and provide the ability to move at progressively faster speeds while engaging (20-120 kph).

Rather than remaining motionless then, weapons mounted on vehicles with contact-based suspensions that are equipped with BOTH point defense and stabilization systems would be able to move at speeds up to the maximum allowed by the stabilizer system (?).

The increase in rounds per level of exceptional success makes sense too. Jec10, does this compare favorably with Striker?

The point on MRLs and other 'saturation' systems makes sense too - I think Jec10 mentioned something about that in an earlier post and I missed it...

 

[jec10]

These are all good points (although I'd beg to differ on the ground-vehicle move and fire one, CT/Striker is quite specific that any ground vehicles may not be moving and engaging in PD fire, and CT/Striker has stabilisation systems for guns as well) but the problem, as I've already tried to explain is that MT combat is not at all like Striker when it comes to indirect fire. Its not clear to me at all how the designers intended indirect fire to work in MT - can someone explain who has actually done it in a gaming session. From my reading of the Players Manual, it isn't clear what role ROF for indirect fire weapons plays. Are they seriously expecting you to roll scatter individually for potentially dozens of incoming shells? Completely barmy.