Vehicle Combat

[JFGarber]

It's been too long since I've used some of these rules, and I've forgotten too much.

When a character (say with a plasma gun with PEN = 25/1 and damage of 13) attacks a vehicle (listed as 10G armor and 7/18 hull points), how do I convert from Referee's Manual stats to Player's Manual?

Is armor a straight transfer and ignore the material type? That would make sense--there are early tech slug throwers that could damage ground cars while a grav tank with armor 55 is immune to darn near anything character portable,while the G-Carrier above can be reasonably threatened by even character portable plasma.

Hull/locomotion/power points must get a multiplier. There's no way a single kick disables a ground car. Perhaps 10? That gives the G-Carrier 70/180 hull point allowing it to absorb 6 plasma gun hits. That is for a paramilitary vehicle, but still seems high.

Thanks in advance for your perspective.

 

[McPerth]

Hull/locomotion/power points must get a multiplier. There's no way a single kick disables a ground car. Perhaps 10? That gives the G-Carrier 70/180 hull point allowing it to absorb 6 plasma gun hits. That is for a paramilitary vehicle, but still seems high. .

From Consolidated MT Errata:

For purposes of personal combat only, multiply a vehicle’s hit value by 10 before starting the combat session. For example, a ground car lists hull hits of 2/5. Its actual hit value in personal combat is 20/50 (multiplied by 10). In a similar manner, its locomotion and power plant hits are each 10/20 (1/2 multiplied by 10).

 

[AnotherDilbert]

Note that the penetration is 25/1 so is halved for each rangeband. See Attenuation (PM, p70).

Penetration is 25 at Short range, 12 at Medium range, and 6 at Long range.

So the vehicle takes full damage at Short range (<5 m) [high penetration], half damage at Medium range (<50 m) [low penetration], and negligible damage (10% so 1 damage) at longer ranges [zero penetration]. (MT PM, p70)

This if further modified for Marginal (50%) or Exceptional Success (200-800%). (PM, p70-71).

Also note that a hit on a vehicle can hit a subsystem. See Hit Location tables PM p74.


A kick (count as club?) with a Pen of 2 and damage 2 would inflict 10% rounded down to no damage to a vehicle.


I'm not sure the errata is needed or appropriate. It would make the very lightly armoured GCarrier invulnerable except at point blank range, and even then it would take many hits to inconvenience it...

Note that even an unarmoured Ground Car (armour 4) is rather difficult to damage with anything lighter than 9mm Rifle or Gauss Pistol even at Short range.

 

[McPerth]

MT penetratin rules have some flaws:

Some months ago, in another thread, there was an argument about how damage is applied to vehicles in zero penetration case.

Today, reviewing Traveller Digest nº 20 Q&A (*), I saw in zero penetration situation damage is given as NE with a note that says vehicles and robots take 10% damage as superstructure hits. So, personnel takes no damage (al long as armor is fully closed) and vehicles/robots 10% damage as superstructure (regardles if its armor is complete or it's not) if their armor is higher than penetration.

This gives us a paradoxal situation:

In a planet with standard atmosphere, we have a zone about 200 m in diameter where there are 6 Trepida Tanks (armor 40) and 15 soldiers in vacc suits (armor 5). (Trepidas took most of the budget and there was not money for better personal armor...).

A starship acting as ortillery support fires a factor 7 PA against them, hitting the center of the zone (standard hit, rolling just what is needed, so no multipliers for damage, nor automatic hits). Danger space is (factor x 15), so 105 m radius, affecting all the troops.

As atmosphere is denser than trace, penetration for PAs is 0. Of course distance is irrelevant (as long as it is in range), as you can halve 0 as much as you want and it won't change anything. So both troops and tanks are in zero penetration situation.

Damage for PAs is 2000. Troops are fully enclosed by armor, so, as zero penetration rules say, they are unhurt. Tanks are likewise fully enclosed, in zero penetration situation, but, as they are vehicles, they recieve 10% damage (200 hits) each as superstructure hits.

So, after the hit, we have 6 smoking destroyed Trepidas and 15 unhurt infantrymen in vacc suit...

As much as I try, I cannot see any logic in this outcome, and I feel it's against rules spirit to allow PAs to be used as ortillery in atmosphere in first place, and making tanks more vulnerable than lighty armored infantrymen in second place. So I think something is flawed on those rules.

I know it's an extreme situation, but I've always believed extremes are the best to show the flaws in most rules/laws.

This quote is from the thread about MT errata ,and has been partially fixed in the consolidated errata 2013.

Don's untimely passing away has stopped, AFAIK, errata updates.

 

[AnotherDilbert]

MT penetratin rules have some flaws:

Today, reviewing Traveller Digest nº 20 Q&A (*), I saw in zero penetration situation damage is given as NE with a note that says vehicles and robots take 10% damage as superstructure hits. So, personnel takes no damage (al long as armor is fully closed) and vehicles/robots 10% damage as superstructure (regardles if its armor is complete or it's not) if their armor is higher than penetration.
...
So, after the hit, we have 6 smoking destroyed Trepidas and 15 unhurt infantrymen in vacc suit...

As much as I try, I cannot see any logic in this outcome, and I feel it's against rules spirit to allow PAs to be used as ortillery in atmosphere in first place, and making tanks more vulnerable than lighty armored infantrymen in second place. So I think something is flawed on those rules.

I know it's an extreme situation, but I've always believed extremes are the best to show the flaws in most rules/laws.

This quote is from the thread about MT errata ,and has been partially fixed in the consolidated errata 2013.

Agreed that extreme test cases are good tests.

The simple solution is to treat vehicles exactly like characters and only apply 10% damage to exposed unarmoured areas, i.e. none on a tank.

If penetration is less than the armor value, the weapon inflicts 10 percent of its damage point value if the target is a character with exposed areas of less than the full armor value.
On the other hand, if the character is fully enclosed in the armor, the hit has no effect.
Vehicles and robots always apply such hits as structure damage. [This does not say that vehicles always take 10% damage, only that vehicles do not use the Hit Location table for low penetration results.]
This is known as a zero penetration result.
[line breaks added]

Note that this is still problematic as 2000 damage should kill both the infantry and the tanks, armour or no. So perhaps apply a minimum of 1% damage (round down) in the fully enclosed case.


The errata solution does not even come close to solving this problem.

 

[JFGarber]

So the vehicle takes full damage at Short range (<5 m) [high penetration], half damage at Medium range (<50 m) [low penetration], and negligible damage (10% so 1 damage) at longer ranges [zero penetration]. (MT PM, p70)
....
I'm not sure the errata is needed or appropriate. It would make the very lightly armoured GCarrier invulnerable except at point blank range, and even then it would take many hits to inconvenience it...

Note that even an unarmoured Ground Car (armour 4) is rather difficult to damage with anything lighter than 9mm Rifle or Gauss Pistol even at Short range.

The x10 makes sense to me. I'm OK with a ground car being difficult to damage with handheld slug throwers. And once I studied 101 Vehicles a little more I realized that the G-Carrier is reasonably resilient to most anything man-portable at range, but is very vulnerable to its own armament. That feels about right.

 

[JFGarber]

Thank you both.

 

[AnotherDilbert]

The x10 makes sense to me. I'm OK with a ground car being difficult to damage with handheld slug throwers.

Take this example: an M-16 shooting at a regular Ground Car.
A 5 mm Assault Rifle has Pen 3/2 and Dam 3.
A Ground Car has Armour 4 and Hull 2/5 modified to 20/50.

The assault rifle can't penetrate so does 0 damage or 1 damage on exceptional success. We can unload a few mags into the car without doing more than scratching the paint. It would take 20 Exceptional Success results to inconvenience the car.

Hitting a moving car at Medium range is a Difficult task with a -4 DM, modified to Routine for large target, so we need to roll 11+ for marginal success and 13+ for exceptional success.

At Long Range (>50 m) this turns into 15+ for exceptional success and the car and its occupants are virtually immune to small arms fire.


Even an anti-tank grenade launcher with damage 6 would take about four hits to seriously damage a regular car.



Example 2:
The Trepida grav tank used earlier.
It has armour 40 and Hull 12/29 modified to 120/290. Its main armament is Fusion X-14 with Pen 67/5 and damage 30.

Shooting at itself it can only achieve low penetration (15 damage) so it would take 8 good hits to incapacitate it and 20 good hits to destroy it.



The ×10 damage points for vehicles leads to unarmoured cars being almost immune to small arms and tanks that are very, very difficult to kill even with heavy anti-tank weapons. I think that is inappropriate.

 

[aramis]

The ×10 damage points for vehicles leads to unarmoured cars being almost immune to small arms and tanks that are very, very difficult to kill even with heavy anti-tank weapons. I think that is inappropriate.

It was intended to be a scale factor, not a flat x10.

It can be much better worded:

multiply all vehicle damage points by 10.
Area effect and energy weapons weapons targeting a vehicle do 10x listed damage to the vehicles, but listed to characters and animals under 5 tons.
Flechette rounds do not get the damage bonus.
​

Note that most vehicle weapons do area effect excepting KEAP and flechette rounds.

No simulation is perfect.

 

[AnotherDilbert]

No simulation is perfect.

Agreed.

It can be much better worded:

multiply all vehicle damage points by 10.
Area effect and energy weapons weapons targeting a vehicle do 10x listed damage to the vehicles, but listed to characters and animals under 5 tons.
Flechette rounds do not get the damage bonus.
​

Note that most vehicle weapons do area effect excepting KEAP and flechette rounds.

That is just a complicated way of saying that slugs and KEAP (APDS) are ineffective against vehicles.

Take the standard Rheinmetall 12 cm tank gun.
HE would be Pen 19 Dam 160
KEAP(APDS) would be Pen 33 Dam 12
It would basically be unable to hurt tanks, since the HE round would not penetrate and the APDS round would barely do any damage at all, even with full penetration. A near miss with a HE round would do more damage with zero penetration (16) than the APDS with full penetration (12).
That seems to be a rather bad simulation of reality.



I frankly don't see the problem the erratum is trying to solve.

In the book system vehicles don't fall apart under small arms fire or because they are kicked, but can be one-shot disabled by anti-materiel and anti-tank weapons. Isn't that as it should be?

 

[mike wightman]

The M-16 versus a typical ground car example is hardly a simulation of what really happens.

Hollywood may have car body panels stopping 5.56 rounds but the truth is very different...

 

[kilemall]

The M-16 versus a typical ground car example is hardly a simulation of what really happens.

Hollywood may have car body panels stopping 5.56 rounds but the truth is very different...

My favorite is people diving behind furniture and my ref brain automatically assuming the couch/bar is made of steel and concrete given the results.

 

[AnotherDilbert]

Hollywood may have car body panels stopping 5.56 rounds but the truth is very different...

The problem is the Ground Car is too heavily armoured; armour 4 is about 12.5 mm (½") of soft steel.

A real car would barely be armour 1 and hence readily penetrated by common small arms.

 

[mike wightman]

Yup, I agree. There are quite a few 'odd' design decisions in the MT vehicles.

 

[McPerth]

Example 2:
The Trepida grav tank used earlier.
It has armour 40 and Hull 12/29 modified to 120/290. Its main armament is Fusion X-14 with Pen 67/5 and damage 30.

Shooting at itself it can only achieve low penetration (15 damage) so it would take 8 good hits to incapacitate it and 20 good hits to destroy it.

The Trepida wil lb efiring as a crew weapon, so, being TL14, it will hit as a simple task up to long sitance, routine up to distant and difficult for Vdistant.

Let's imagine it fires t oanother Trepida at 4 km (distant). It's a routine task, with low pen situation (so DMG is 50%, so 15). If we asume the gunner to hae dex 7 and skill 2 (rather average in MT), he wil have a +3 DM, so:

• On a roll of 4, modified to 7, he hits as marginal success: 7 DPs
• On a roll of 5, modified to 8, he hits as normal success: 15 DPs
• On a roll of 6-7, modified to 9-10, he hits as exceptional success x2: 30 DPs
• On a roll of 8-9, modified to 11-12, he hits as exceptional success x4: 60 DPs
• On a roll of 10-11, modified to 13-14, he hits as exceptional success x8: 120 DPs

So, you can incapacite it on a roll of 10+at 4 km distance...

And this assumes only superstructure is hit, as other damages may be taken into account...

Add to this the pinpoint rules that allow you to pinpoint those locations...So, if you pinpoint the PP (why not to do, as it hs no drwbacks?), any exceptional sucess (so, as above, a roll of 6+) will achieve 30+ hits at structure and PP, so killing the Trepida (IIRC, I don't have my 101 vehicles handy)

Let's imagine it is not so increased:

A longbow achieving an exceptional success may do 1-3 DP to its superstructure. So, about a dozen such hits will leave the Trepida inoperable...

So, what seems to you a better simulation?

The problem is the Ground Car is too heavily armoured; armour 4 is about 12.5 mm (½") of soft steel.

A real car would barely be armour 1 and hence readily penetrated by common small arms.

Fully agreed here.

 

[AnotherDilbert]

Let's imagine it fires t oanother Trepida at 4 km (distant). It's a routine task, with low pen situation (so DMG is 50%, so 15). If we asume the gunner to hae dex 7 and skill 2 (rather average in MT), he wil have a +3 DM, so:

• On a roll of 4, modified to 7, he hits as marginal success: 7 DPs
• On a roll of 5, modified to 8, he hits as normal success: 15 DPs
• On a roll of 6-7, modified to 9-10, he hits as exceptional success x2: 30 DPs
• On a roll of 8-9, modified to 11-12, he hits as exceptional success x4: 60 DPs
• On a roll of 10-11, modified to 13-14, he hits as exceptional success x8: 120 DPs

So, you can incapacite it on a roll of 10+at 4 km distance...

You forgot a few modifiers...

It's a large target so one level easier task; modified to Simple task.

Cover: can make the task one level harder; potentially back to Routine.

Movement: Both the firer and target may select a movement rate and hence movement DM up to -100 (or -195 in vacuum). The difference between their DMs is applied to any firing task between them divided by 16 for Distant range.

Evade: Both firer and target may choose to Evade doubling their movement DM.

So we have to apply a DM of somewhere from -0 to -24 for movement.

Yes, we can easily hit and destroy a target sitting still in plain sight in the open at short range, but that isn't very surprising...

(Yes, 4 km is short range for a weapon with 500 km range...)

A longbow achieving an exceptional success may do 1-3 DP to its superstructure. So, about a dozen such hits will leave the Trepida inoperable...

Bowmen, riflemen, attacking mosquitoes, they all do the same damage on Exceptional Success. That is quite bad, but it requires the vehicle to sit still within range of the attackers. If you just zoom past the movement DM will prevent any hits.

The mechanism is questionable, but making vehicles immune to infantry is probably even worse.

So, what seems to you a better simulation?

Something simpler, this is way to complicated to use at the table.

I don't mind complicated design systems, they are used between sessions. But at the table the combat system must be quick and simple enough for everyone to follow.