Combat System C

[tbeard1999]

After a weekend of tinkering (dodging the hurricane), here's "Combat System C" (because it's the 3rd major combat system I've created for Traveller). Attached to this file is a detailed system including small arms and armor through TL 15. Basically, its the CT Proposed System, with refinements and a movement and combat sequence. Please give it a try and I welcome questions, comments, and complaints.

The fire combat system is modular and can be implemented separately from the combat sequence of play.

Fast Overview

Fire Resolution

1. Roll to hit on 2D. Base to hit roll is 8+. Add to hit modifiers.

2. For each hit, roll penetration (1d6+penetration). If the roll equals or exceeds the target's armor rating, the hit penetrates.

3. Roll damage for penetrating hits.

Note: This moves fast because there's only 1 die roll to hit (even with automatic weapons) even though multiple hits can be scored with an autofire burst. Then, each penetration die can be rolled at the same time. Then, all damage can be rolled at the same time (except for the First Hit in Combat damage).

Melee Strike Resolution

1. Roll to hit on 2D. Base to hit roll is 8+. Add to hit modifiers.

2. For each hit, roll penetration (1d6+penetration). If the roll equals or exceeds the target's armor rating, the hit penetrates.

3. Roll damage for penetrating hits. Damage is allocated exactly like CT.

Combat Sequence of Play

1. Initiative Roll.

2. Declare Cover.

3. Suppressive Fire.

4. Movement & Snapshots.

5. Normal Fire.

As I update the system, I'll post revised PDFs.

Updates:
V1.2

EDIT: To comply with COI rules, the PDF has been moved here: http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=17031

A direct link to the PDF is at http://www.travellerrpg.com/CotI/Discuss/attachment.php?attachmentid=273&d=1223413088

 

[far-trader]

A quick observation, not sure how it applies if at all

The thing that always bothers me about detailing the "to hit" roll of an abstracted system by adding an "armor pentration" roll is what about the attacks that "hit" but don't "penetrate"? Shouldn't they have an effect? Damage the armor or other items the target has? Scare the person? Knock the wind out of them? Severely bruise them even? All things I usually put down to the low damage rolls for hits. But with an armor penetration roll what are the low damage rolls? The bullet punctures your armor but miraculously is stopped from doing serious damage by your dog tags?

Same problem comes up with most (if not all) "hit location" rules I've seen.

Anyway, that's just me being a crank But I'd be interested in your take on the point.

 

[dean]

I laughed out loud at the inclusion of the John Woo Factor.
Looks decent, what it's designed for is what you need for your campaign.

 

[tbeard1999]

A quick observation, not sure how it applies if at all

The thing that always bothers me about detailing the "to hit" roll of an abstracted system by adding an "armor pentration" roll is what about the attacks that "hit" but don't "penetrate"? Shouldn't they have an effect? Damage the armor or other items the target has? Scare the person? Knock the wind out of them? Severely bruise them even? All things I usually put down to the low damage rolls for hits. But with an armor penetration roll what are the low damage rolls? The bullet punctures your armor but miraculously is stopped from doing serious damage by your dog tags?

Same problem comes up with most (if not all) "hit location" rules I've seen.

Anyway, that's just me being a crank But I'd be interested in your take on the point.

My first thought is that the penetration system is designed to resolve serious damage. Damage from non-penetrating hits should be left up to the referee (although see my Knockback rules for campaigns with high JWF (John Woo Factor). And some kinds of weapons may not require penetration to have an effect. If I shoot you with a dart smeared with nerve agent, a non-penetrating hit will still leave some deadly nerve agent on your armor. If you're careless and touch it, you'll be in trouble. And as referee, if you get hit with an HEAP round, I might make you make a saving throw to avoid damage to your delicate electrobinoculars. Sadistic referees might even require a roll to see if large and/or valuable equipment is hit first. Just to be snide, I'd even add +1 to the target's armor value after the valuable piece of gear is torn up...

In a situation where the armor is penetrated, but the damage roll is unusually low, I'd simply interpret that as a hit on a non-critical area--a "flesh wound" that grazes the edge of the arm, torso, cheek, etc. If dramatically appropriate, I like your idea--your cigarette lighter, dog tags, pocket Orange Catholic Bible, MRE biscuit pack, etc., slows the bullet down.

 

[tbeard1999]

I laughed out loud at the inclusion of the John Woo Factor.
Looks decent, what it's designed for is what you need for your campaign.

Ultimately (and ideally) what will emerge will be a toolkit of mechanics. Much like the armor options, each main mechanic will have several options to allow GMs to tailor the combat system to their tastes.

 

[tbeard1999]

Updated PDF to V1.2

Corrected misc typos. Changed and expanded description of additional targets and fire lane rules. Made separate archaic armor section. Added archaic shields. Changed "John Woo Rating" to "John Woo Factor". PDF is in first post of this thread.

 

[beowulf2044]

In JTAS #13 and the article on the 4mm Gauss Pistol by Terry McInnes, he wrote that the damage for the pistol was 4D6, and the weapon had the capability for either single shot or four round burst. It was also illegal at Law level 4 and above.

Just thought I'd pass this along for your consideration.

 

[tbeard1999]

In JTAS #13 and the article on the 4mm Gauss Pistol by Terry McInnes, he wrote that the damage for the pistol was 4D6, and the weapon had the capability for either single shot or four round burst. It was also illegal at Law level 4 and above.

Just thought I'd pass this along for your consideration.

Thanks! My damage calculations are based on certain assumptions about muzzle velocity and projectile mass. Gauss pistols in CS3 do 3D damage and are capable of autofire. But what really distinguishes them is the higher ammunition load compared to other pistols (which makes the autofire capability as nasty as an SMG) and high penetration.

Since damage and penetration are distinct variables, I don't see any harm in positing a "heavy" (say, 6mm) gauss pistol that does more damage but only carries 10-12 rounds (due to the extra space consumed by a larger power pack and larger bullets).

 

[tbeard1999]

Explosives Damage

Here's the first draft of my damage scale for explosives. EDIT: Second draft now.

Basically, kinetic energy weapons will do damage based on their penetration (some adjustment will be made for small arms, especially pistols). The current rule of thumb is Penetration/2 equals dice of damage.

Weapons using high explosives will do contact damage based on the mass of explosives in the warhead. As with armor, materials tech and everything else, I assume that the mass efficiency of high explosives will continue to advance:

TL	Decr.	ME
5	TNT	.8
8	RDX, etc	1.00
9		2
10		3
11		4
12		5
13		6
14		7
15		8

So, to determine the damage of an HE warhead, determine the amount of explosives (in kg) in its warhead, multiply that by the explosive's ME and consult the chart below. In the case of HE bullets, add the HE damage to the damage rating of a normal bullet (minimum of +1D).

To determine the damage of an HEAP (high explosive armor piercing) warhead, determine the amount of explosives (in kg) in its warhead, multiply that by the explosive's ME and consult the chart below. In the case of HEAP bullets, add the HE damage to the damage rating of a normal bullet (minimum of +1D). Determine fragmentation from the amount of HE in the bullet.

Fragmentation damage is tentative, but here's how I see it working:

If a target is hit by an HE weapon, the target takes the "Contact" damage. All targets within the "primary blast radius", "secondary blast radius" and "tertiary blast radius" take the listed damage.

A target that straddles two blast radii is considered to be in the higher damage band.

For instance, consider a TL8 4cm fragmentation hand grenade. It has .22kg of TNT. Multiply .22 by TNT's ME of .8 equals .176. Consulting the chart below:

Descr.	 	 Contact	  Primary	 Secondary	 Tertiary
TL8 Grenade 	 2/4D 	 	 4m 2/3D 	 8m 1/1D 	 12m 0/0D

So, it has a primary blast radius of 4m, does 3D damage, penetration 2 to everything within that radius.

Its TL15 counterpart is considerably more effective. It has .22 kg of TL15 megablastium-Q36. Multiply .22 by TL15 explosive's ME of 8 equals 1.76kg. Note that it has a "dial down" capability, where damage can be adjusted to lower settings damage (at full strength, it would be lethal against lighly armored targets out to 46m; this might include the user of the grenade).

Descr.	 	 Contact	 Primary	 Secondary	 Tertiary
TL15 Grenade 	 16/32D 	 15m 16/31D 	 31m 8/15D 	 46m 4/7D

HE Damage Chart (HE)

HE Equiv	 Contact 	 Primary 	 Secondary 	 Tertiary 
 (Kg)	 Pen/Dmg 	 Radius 	 Radius 	 Radius 
 0.05 	 1/2D 	 	 2m 1/1D 	 4m 0/0D 	 6m 0/0D 
 0.10 	 1/3D 	 	 3m 1/2D 	 6m 1/1D 	 9m 0/0D 
 0.15 	 2/4D 	 	 4m 2/3D 	 8m 1/1D 	 12m 0/0D 
 0.20 	 2/5D 	 	 5m 2/4D 	 10m 1/2D 	 15m 1/1D 
 0.25 	 3/6D 	 	 5m 3/5D 	 10m 1/2D 	 15m 1/1D 
 0.30 	 3/7D 	 	 6m 3/6D 	 12m 2/3D 	 18m 1/1D 
 0.35 	 4/8D 	 	 6m 4/7D 	 12m 2/3D 	 18m 1/1D 
 0.40 	 4/9D 	 	 7m 4/8D 	 14m 2/4D 	 21m 1/2D 
 0.45 	 5/10D 	 	 7m 5/9D 	 14m 2/4D 	 21m 1/2D 
 0.50 	 5/11D 	 	 8m 5/10D 	 16m 3/5D 	 24m 1/2D 
 0.55 	 6/12D 	 	 8m 6/11D 	 16m 3/5D 	 24m 1/2D 
 0.60 	 6/13D 	 	 8m 6/12D 	 16m 3/6D 	 24m 2/3D 
 0.65 	 7/14D 	 	 9m 7/13D 	 18m 3/6D 	 27m 2/3D 
 0.70 	 7/15D 	 	 9m 7/14D 	 18m 4/7D 	 27m 2/3D 
 0.75 	 8/16D 	 	 9m 8/15D 	 18m 4/7D 	 27m 2/3D 
 0.80 	 8/17D 	 	 9m 8/16D 	 18m 4/8D 	 27m 2/4D 
 0.85 	 9/18D 	 	 10m 9/17D 	 20m 4/8D 	 30m 2/4D 
 0.90 	 9/19D 	 	 10m 9/18D 	 20m 5/9D 	 30m 2/4D 
 0.95 	 10/20D 	 10m 10/19D 	 20m 5/9D 	 30m 2/4D 
 1.00 	 10/21D 	 10m 10/20D 	 20m 5/10D 	 30m 3/5D 
 1.05 	 11/22D 	 10m 11/21D 	 21m 5/10D 	 31m 3/5D 
 1.10 	 11/23D 	 11m 11/22D 	 22m 6/11D 	 33m 3/5D 
 1.16 	 12/24D 	 11m 12/23D 	 23m 6/11D 	 34m 3/5D 
 1.22 	 12/25D 	 12m 12/24D 	 24m 6/12D 	 36m 3/6D 
 1.28 	 13/26D 	 12m 13/25D 	 25m 6/12D 	 37m 3/6D 
 1.34 	 13/27D 	 13m 13/26D 	 26m 7/13D 	 39m 3/6D 
 1.41 	 14/28D 	 13m 14/27D 	 27m 7/13D 	 40m 3/6D 
 1.48 	 14/29D 	 14m 14/28D 	 28m 7/14D 	 42m 4/7D 
 1.55 	 15/30D 	 14m 15/29D 	 29m 7/14D 	 43m 4/7D 
 1.63 	 15/31D 	 15m 15/30D 	 30m 8/15D 	 45m 4/7D 
 1.71 	 16/32D 	 15m 16/31D 	 31m 8/15D 	 46m 4/7D 
 1.80 	 16/33D 	 16m 16/32D 	 32m 8/16D 	 48m 4/8D 
 1.89 	 17/34D 	 16m 17/33D 	 33m 8/16D 	 49m 4/8D 
 1.98 	 17/35D 	 17m 17/34D 	 34m 9/17D 	 51m 4/8D 
 2.08 	 18/36D 	 17m 18/35D 	 35m 9/17D 	 52m 4/8D 
 2.18 	 18/37D 	 18m 18/36D 	 36m 9/18D 	 54m 5/9D 
 2.29 	 19/38D 	 18m 19/37D 	 37m 9/18D 	 55m 5/9D 
 2.41 	 19/39D 	 19m 19/38D 	 38m 10/19D 	 57m 5/9D 
 2.53 	 20/40D 	 19m 20/39D 	 39m 10/19D 	 58m 5/9D 
 2.65 	 20/41D 	 20m 20/40D 	 40m 10/20D 	 60m 5/10D 
 2.79 	 21/42D 	 20m 21/41D 	 41m 10/20D 	 61m 5/10D 
 2.93 	 21/43D 	 21m 21/42D 	 42m 11/21D 	 63m 5/10D 
 3.07 	 22/44D 	 21m 22/43D 	 43m 11/21D 	 64m 5/10D 
 3.23 	 22/45D 	 22m 22/44D 	 44m 11/22D 	 66m 6/11D 
 3.39 	 23/46D 	 22m 23/45D 	 45m 11/22D 	 67m 6/11D 
 3.56 	 23/47D 	 23m 23/46D 	 46m 12/23D 	 69m 6/11D 
 3.73 	 24/48D 	 23m 24/47D 	 47m 12/23D 	 70m 6/11D 
 3.92 	 24/49D 	 24m 24/48D 	 48m 12/24D 	 72m 6/12D 
 4.12 	 25/50D 	 24m 25/49D 	 49m 12/24D 	 73m 6/12D 
 4.32 	 25/51D 	 25m 25/50D 	 50m 13/25D 	 75m 6/12D 
 4.54 	 26/52D 	 25m 26/51D 	 51m 13/25D 	 76m 6/12D 
 4.76 	 26/53D 	 26m 26/52D 	 52m 13/26D 	 78m 7/13D 
 5.00 	 27/54D 	 26m 27/53D 	 53m 13/26D 	 79m 7/13D 
 5.25 	 27/55D 	 27m 27/54D 	 54m 14/27D 	 81m 7/13D 
 5.52 	 28/56D 	 27m 28/55D 	 55m 14/27D 	 82m 7/13D 
 5.79 	 28/57D 	 28m 28/56D 	 56m 14/28D 	 84m 7/14D 
 6.08 	 29/58D 	 28m 29/57D 	 57m 14/28D 	 85m 7/14D 
 6.39 	 29/59D 	 29m 29/58D 	 58m 15/29D 	 87m 7/14D 
 6.70 	 30/60D 	 29m 30/59D 	 59m 15/29D 	 88m 7/14D 
 7.04 	 30/61D 	 30m 30/60D 	 60m 15/30D 	 90m 8/15D 
 7.39 	 31/62D 	 30m 31/61D 	 61m 15/30D 	 91m 8/15D 
 7.76 	 31/63D 	 31m 31/62D 	 62m 16/31D 	 93m 8/15D 
 8.15 	 32/64D 	 31m 32/63D 	 63m 16/31D 	 94m 8/15D 
 8.56 	 32/65D 	 32m 32/64D 	 64m 16/32D 	 96m 8/16D 
 8.99 	 33/66D 	 32m 33/65D 	 65m 16/32D 	 97m 8/16D 
 9.43 	 33/67D 	 33m 33/66D 	 66m 17/33D 	 99m 8/16D 
 9.91 	 34/68D 	 33m 34/67D 	 67m 17/33D 	 100m 8/16D 
 10.40 	 34/69D 	 34m 34/68D 	 68m 17/34D 	 102m 9/17D 
 10.92 	 35/70D 	 34m 35/69D 	 69m 17/34D 	 103m 9/17D 
 11.47 	 35/71D 	 35m 35/70D 	 70m 18/35D 	 105m 9/17D 
 12.04 	 36/72D 	 35m 36/71D 	 71m 18/35D 	 106m 9/17D 
 12.64 	 36/73D 	 36m 36/72D 	 72m 18/36D 	 108m 9/18D 
 13.27 	 37/74D 	 36m 37/73D 	 73m 18/36D 	 109m 9/18D 
 13.94 	 37/75D 	 37m 37/74D 	 74m 19/37D 	 111m 9/18D 
 14.64 	 38/76D 	 37m 38/75D 	 75m 19/37D 	 112m 9/18D 
 15.37 	 38/77D 	 38m 38/76D 	 76m 19/38D 	 114m 10/19D 
 16.14 	 39/78D 	 38m 39/77D 	 77m 19/38D 	 115m 10/19D 
 16.94 	 39/79D 	 39m 39/78D 	 78m 20/39D 	 117m 10/19D 
 17.79 	 40/80D 	 39m 40/79D 	 79m 20/39D 	 118m 10/19D 
 18.68 	 40/81D 	 40m 40/80D 	 80m 20/40D 	 120m 10/20D 
 19.61 	 41/82D 	 40m 41/81D 	 81m 20/40D 	 121m 10/20D 
 20.59 	 41/83D 	 41m 41/82D 	 82m 21/41D 	 123m 10/20D 
 21.62 	 42/84D 	 41m 42/83D 	 83m 21/41D 	 124m 10/20D 
 22.70 	 42/85D 	 42m 42/84D 	 84m 21/42D 	 126m 11/21D 
 23.84 	 43/86D 	 42m 43/85D 	 85m 21/42D 	 127m 11/21D 
 25.03 	 43/87D 	 43m 43/86D 	 86m 22/43D 	 129m 11/21D 
 26.28 	 44/88D 	 43m 44/87D 	 87m 22/43D 	 130m 11/21D 
 27.60 	 44/89D 	 44m 44/88D 	 88m 22/44D 	 132m 11/22D 
 28.98 	 45/90D 	 44m 45/89D 	 89m 22/44D 	 133m 11/22D 
 30.43 	 45/91D 	 45m 45/90D 	 90m 23/45D 	 135m 11/22D 
 31.95 	 46/92D 	 45m 46/91D 	 91m 23/45D 	 136m 11/22D 
 33.55 	 46/93D 	 46m 46/92D 	 92m 23/46D 	 138m 12/23D 
 35.22 	 47/94D 	 46m 47/93D 	 93m 23/46D 	 139m 12/23D 
 36.98 	 47/95D 	 47m 47/94D 	 94m 24/47D 	 141m 12/23D 
 38.83 	 48/96D 	 47m 48/95D 	 95m 24/47D 	 142m 12/23D 
 40.77 	 48/97D 	 48m 48/96D 	 96m 24/48D 	 144m 12/24D 
 42.81 	 49/98D 	 48m 49/97D 	 97m 24/48D 	 145m 12/24D 
 44.95 	 49/99D 	 49m 49/98D 	 98m 25/49D 	 147m 12/24D 
 47.20 	 50/100D 	 49m 50/99D 	 99m 25/49D 	 148m 12/24D 
 49.56 	 50/101D 	 50m 50/100D 	 100m 25/50D 	 150m 13/25D 
 52.04 	 51/102D 	 50m 51/101D 	 101m 25/50D 	 151m 13/25D 
 54.64 	 51/103D 	 51m 51/102D 	 102m 26/51D 	 153m 13/25D 
 57.37 	 52/104D 	 51m 52/103D 	 103m 26/51D 	 154m 13/25D 
 60.24 	 52/105D 	 52m 52/104D 	 104m 26/52D 	 156m 13/26D 
 63.25 	 53/106D 	 52m 53/105D 	 105m 26/52D 	 157m 13/26D 
 66.42 	 53/107D 	 53m 53/106D 	 106m 27/53D 	 159m 13/26D 
 69.74 	 54/108D 	 53m 54/107D 	 107m 27/53D 	 160m 13/26D 
 73.22 	 54/109D 	 54m 54/108D 	 108m 27/54D 	 162m 14/27D 
 76.89 	 55/110D 	 54m 55/109D 	 109m 27/54D 	 163m 14/27D 
 80.73 	 55/111D 	 55m 55/110D 	 110m 28/55D 	 165m 14/27D 
 84.77 	 56/112D 	 55m 56/111D 	 111m 28/55D 	 166m 14/27D 
 89.01 	 56/113D 	 56m 56/112D 	 112m 28/56D 	 168m 14/28D 
 93.46 	 57/114D 	 56m 57/113D 	 113m 28/56D 	 169m 14/28D

 

[tbeard1999]

High Explosive Armor Piercing Rounds (HEAP)

HEAP rounds use a shaped charge to penetrate armor. Very simply, the explosive is shaped to form a long, thin, plasma jet comprised of the liner material (usually copper or depleted uranium these days) and explosive.

HEAP rounds are typically less effective against infantry than comparable-sized HE rounds, primarily because the HEAP round has to devote considerable mass to the liner, while the HE rounds can contain more explosive and fragmentation material (typically 50%-100% more).

To determine the damage and penetration in Combat System C, use the following formula.

1. Multiply the mass of explosive (in kg) of the explosive in the warhead by the mass efficiency of the explosive material. In most cases, TL5-6 warheads will be considered "TNT", regardless of actual composition. The result is the warhead equivalent mass (this is the equivalent amount of TL7 explosive, in kg) and is expressed in kg.

Explosive Mass Efficiency Table
TL	Decr.	ME
8-	RDX, etc	1.00
9		2
10		3
11		4
12		5
13		6
14		7
15		8

Example--A TL5 M307A1 56mm recoilless rifle (aka "bazooka") HEAT round has 0.18 kg of explosive. Multiply 0.18 x 1 = .18. The warhead equivalent mass is 0.18.

2. Multiply the warhead equivalent mass by the penetration number given in the HEAT Warhead Penetration Chart to determine the penetration of the round in cm of RHA. Double the final penetration if the original explosive weighed less than 0.2 kg:

TL	Liner		PN
5-6	Steel		20
7	Copper		25
8	DU		30
8	DU/Tand		40
8	Copper/Tand	35

"Tand" = Tandem or multiple penetrators.

Example--the 56mm round above is a TL 5 round, so its PN is 20. Multiply its warhead equivalent mass of .18 by 20 = 3.6. Double that because the explosive weighed less than 0.2kg. Final penetration is 7.2 cm of RHA.

3. Determine the penetration by referencing the Penetration/Damage chart.

Example--the 56mm round above will penetrate 7.2 cm of RHA. This corresponds to a penetration of 16.

4. Determine the damage by referencing the HE damage chart. The warhead equivalent mass is used in the HE Eq. Mass column. Use the penetration determined in step 3 for contact penetration. Use the values on the HE damage chart for primary, secondary and tertiary radii.

Example--the 56mm round above has a warhead equivalent mass of 0.18. This corresponds to a contact damage of 4D. So the round looks like this:

Contact: 16/4D
Primary: 4m 2/3D
Secondary: 8m 1/1D
Tertiary: 12m 0/0D

For comparison, let's consider a TL15 version.

It has 0.18kg of TL15 megablastium 4. Its warhead equivalent mass is 0.18 x 8 = 1.44 kg. It has a DU/Tandem warhead, so its penetration in cm of RHA is 1.44 x 40 = 57.6 cm. This corresponds to a penetration of 46. Consulting the HE damage chart, we find that 1.44 kg HE equivalent has a contact damage of 28D. So, the round looks like this:

Contact: 46/28D
Primary: 13m 14/27D
Secondary: 27m 7/13D
Tertiary: 40m 3/6D

Note that this TL15 bazooka round will knock out any TL6- Real World main battle tank from the front. It could penetrate some TL7 main battle tanks from the front depending on where it hits. It could probably defeat the side armor of main battle tanks through TL8. Like its TL5 counterpart, it's quite an anemic weapon, although better than nothing. Of course, it would be devastating against unarmored targets.

 

[tbeard1999]

Rating Small Arms -- Penetration and Damage

Here's my draft small arms rating system for penetration and damage. A weapon's damage and penetration at effective range is determined by its muzzle energy. (For representative weapons, I used an average of available rounds; I recommend that policy, since special rounds can exploit the break points in the chart and give an unreasonable performance boost).

	Muzzle
	Energy		Pen/	Modern
Rating	(J)		Dmg	Example
1	50-99		-2/1D	.25
2	100-199		-2/2D	.32
3	200-399		-2/3D	.38 Sp
4	400-599		-1/3D	9x19mm; .40 S&W; .45 Auto
5	600-899		0/3D	.357 Mag
6	900-1599		1/3D	.44 Mag; .30 Carbine
7	1600-2599	2/3D	5.56x45; 7.62x39
8	2600-4599	3/3D	7.62x51; .30-06
9	4600-6599	4/3D	338 Win Mag
10	6600-9599	5/3D	.470 Nitro
11	9600-13599	6/3D
12	13600-18599	7/4D	12.7x99 (.50 Cal)
13	18600-23999	7/5D
14	24000-30999	8/6D	14x114 (14mm HMG)
15	31000-38999	8/7D
16	39000-47999	8/8D
17	48000+		9/9D

 

[pendragonman]

Here's my draft small arms rating system for penetration and damage. A weapon's damage and penetration at effective range is determined by its muzzle energy. (For representative weapons, I used an average of available rounds; I recommend that policy, since special rounds can exploit the break points in the chart and give an unreasonable performance boost).

A very reasonable policy, I think. If a GM wants to have special rounds they can design their own.

 

[tbeard1999]

Gun Design

I started out intending to build my own gun design system (and may still do so), but in the meantime, I've been designing guns with Fire Fusion and Steel 2. Here are the changes:

1. Design CPR guns normally except as noted below.

2. Weapon penetration and damage is determined by the weapon's Actual Muzzle Energy. Disregard FFS damage and penetration stats. In general, commercially designed weapons will have actual muzzle energy near the middle of each muzzle energy band. Use the penetration/damage chart posted earlier. DS rounds are designed exactly like normal rounds (but use the FFS additional cost), but the penetration will be increased, depending on its TL:

DS Chart	
TL	Pen
0	
8	1
9	2
10	3
11	4
12	5
13	6
14	7
15	8

Actual muzzle energy is 85% at long range and and 75% at extreme range.

3. Weapon ranges depend on the weapon's Actual Range in FFS and its barrel length. Multiply the Actual range times the indicated number on the chart below to get each range. For numbers greater than 20, round down to nearest 10 meters; for numbers less than 20 but greater than 10, round down to nearest 5 meters, for lower numbers round down to the nearest whole number.

Normal Rounds
Barrel Len
(cm)	Effective	Long	Extreme
0	1	4	8
20	2	4	6
30	4	8	12

DS/Gauss Rounds
Barrel Len
(cm)	Effective	Long	Extreme
0	2	8	-
20	3	6	-
30	6	12	-

So, a weapon with a 20 cm barrel and an actual range of 11.8 in FFS will have an effective range of 11.8, rounded down to 11, a long range of 47.2, rounded down to 40, and an extreme range of 94.4, rounded down to 90.

3. Recoil will be added to the combat system later, but here's the basic sketch:

-Each bullet or burst fired by a weapon has a recoil. Compare the total recoil from all shots made in a turn to the figure's STR. For every 2 points of recoil greater than STR (or fraction thereof), the "to hit" roll is modified by -1.

 

[tbeard1999]

v1.6 Posted

Direct link to PDF http://www.travellerrpg.com/CotI/Discuss/attachment.php?attachmentid=273&d=1223413088

Link to thread: http://www.travellerrpg.com/CotI/Discuss/showthread.php?t=17031

This version adds recoil, conversion of real world weapons, and multiple shots.

 

[samuelvss]

I love your system here. I haven't had a chance to use it.

I have a shotgun fetish, though, and enjoyed what you have done with the ammo breakdown! One snigger, though, is the damage of the slugs is just too much: You are talking about less energy than a .308 (7.5 mm autorifle). I'm a big believer in the "bigger/slower" school of terminal ballistics, but I believe 4D should be it for a slug damage.

Also, you can't have a party without inviting Ma Deuce:

TL 5 12.5mm HMG C,A, (+ incapable of fire without a tripod, unless in battledress) Eff/Long/Extr
800/1600/2400 Mag 50 Recoil 24(++).

The ranges are a bit less than you put for the sniper rifle, but for good reason. Despite some great ballistics, 800m is really a good effective range. Even with very practiced gunners we would let the target arrays get to 800m before opening up. I have seen a semi-pro football player carry an unloaded M2 for a good bit (13 km roadmarch), but firing one not mounted to something is just beyond the pale. It is a very nice weapon in a dismounted defense, though it should be served by a crew of 3 dismounted; one can fire it, but to reload, change barrels and the like really takes 3 to do in any kind of combat order. 2 would do so, but at a reduced rate of fire.

 

[tbeard1999]

I love your system here. I haven't had a chance to use it.

Thanks!

I have a shotgun fetish, though, and enjoyed what you have done with the ammo breakdown! One snigger, though, is the damage of the slugs is just too much: You are talking about less energy than a .308 (7.5 mm autorifle). I'm a big believer in the "bigger/slower" school of terminal ballistics, but I believe 4D should be it for a slug damage.

I haven't done the kind of extensive analysis for shotguns that I did for rifles and pistols. So, the damage could definitely be too high (although I do think I ran the numbers). I'll look at it again.

Also, you can't have a party without inviting Ma Deuce:

TL 5 12.5mm HMG C,A, (+ incapable of fire without a tripod, unless in battledress) Eff/Long/Extr
800/1600/2400 Mag 50 Recoil 24(++).

The ranges are a bit less than you put for the sniper rifle, but for good reason. Despite some great ballistics, 800m is really a good effective range. Even with very practiced gunners we would let the target arrays get to 800m before opening up. I have seen a semi-pro football player carry an unloaded M2 for a good bit (13 km roadmarch), but firing one not mounted to something is just beyond the pale. It is a very nice weapon in a dismounted defense, though it should be served by a crew of 3 dismounted; one can fire it, but to reload, change barrels and the like really takes 3 to do in any kind of combat order. 2 would do so, but at a reduced rate of fire.

Looks good to me. I'll add it to the next version of the combat system. Thanks for the input.

 

[Straybow]

I didn't like the GURPS rule-of-thumb for burst fire, so I did the statistics for how many hits in a 3 round burst. That was based on 3d6, but it is a simple matter to do for 2d6.