Things that go Boom! Part 8: Looking at Artillery

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JCab747
March 10, 2019 - 10:29am
And this is a story that builds upon the previous four stories.

What follows are notes.
Joe Cabadas
Comments:

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JCab747
March 10, 2019 - 10:36am

Taking Cover from Bombs and Artillery

Characters caught in the open during an artillery or bomb attack are particularly vulnerable to injury or death.Going prone on the ground should be treated as having hard cover and it will cut the damage/effects of explosive, stun/sonic, and tangler attacks by 75 percent unless the attacker has rolled an automatic hit. Prone characters in the secondary blast radius receive no damage.

Going prone does not protect against gas attacks, but it will mitigate the effects of foam bombs, electrical discharge, field crusher and incendiary warheads. If caught within the immediate blast radius, treat a prone character as being in the secondary blast radius (unless the enemy has rolled an automatic hit). Prone characters in the secondary blast radius receive no damage.

Characters in unarmored vehicles are subject to damage from artillery, bomb and missile attacks. Those in armored vehicles, such as tanks, may have partial or even full protection from damage until any defenses are breached.

Energy screens can protect or reduce the damage done to characters, vehicles and structures.

Taking cover in trenches, underground bunkers, caves, etc. may completely protect characters from damage. But, if a character is in a low-lying shelter, they are potentially even more vulnerable to gas attack weapons.
Joe Cabadas

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JCab747
March 10, 2019 - 10:38am

Artillery Rules

Star Frontiers never provided much in the ways of artillery rules (the only exception was the Sathar automatic cannon that was featured in the “Starspawn of Volturnus” module.

The “Tanks a Lot!” article offered cannons and a howitzer, it never tackled the concepts of indirect fire, time on target(coordinating the fire from many weapons so the rounds land at the same time), or even an abstract idea of how long it takes an artillery shell to travel from its firing location to a distant target. What follows are some suggested house rules providing an Artillery weapons skill, direct fire versus indirect fire, spotters, Time on Target, and counter battery rules.

New Skill: Artillery

Most characters will not be able to use artillery weapons without the specialized Weapons: Artillery skill. An artillerist can fire a weapon directly at a target if he can see it. If he is firing the weapon at a target he cannot see, the artillerist uses indirect fire and will usually need a forward observer of some sort – a character or robot – or will be relying on other remote sensor information or calculating a to-hit roll based upon a known distance. Otherwise, firing such a weapon blindly is almost guaranteed to miss.

Weapons: Artillery

Type: Military PSA/Enforcer

Success Rate: ½ LOG + 10% per level

PR: Alpha Dawn: None; Zebulon: Mathematics 2

A military specialist with this skill is capable of firing artillery-like weapons, maintaining such equipment and acting as an artillery observer. Unlike most weapons skills, it is based ona character’s Logic (LOG) score rather than Dexterity or Strength. Outside of a few specialized planetary militia units and the UPF Landfleet, this skill is uncommon. This character can also use grenade mortars and grenade rifles.

Even if the first few shots miss a target, each turn that a forward observer provides information, the artillerist can add +5% to his success rate to a maximum of +20% bonus.

Joe Cabadas

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JCab747
March 10, 2019 - 10:41am

Direct Fire

As with the use of lasers, gyrojet, projectile and sprayer weapons, an artillerist who has a line-of-sight to his target can fire directly at it. To direct fire a weapon accurately, it  should have a sighting device and the firer needs an unobstructed view of the target.

If there is intervening terrain, buildings, or other units in the way, the attacker cannot use direct fire.

Opponents are easily able to fire back at an artillery unit that utilizes a direct fire attacks.[1]

Heavy Weapon Modifier. Remember attackers using artillery have a -10 percent penalty when firing.

Indirect Fire

Indirect fire is the preferred way that artillery units operate. Targets are out of the line-of-sight of the enemy and munitions are fired on a ballistic trajectory. Shots are normally directed by a forward observer. Artillery can than shoot over obstacles and friendly units while being concealed from direct fire attacks.

However, artillery units are vulnerable to enemy artillery counter-battery fire.[2]

Game use. In addition to the -10 percent modifier for heavy weapons, the artillerist receives an initial -10 percent penalty for using indirect fire. Each turn that a forward observer provides information, the artillerist can add +5% to his success rate to a maximum of +20% bonus. (This adjustment of fire is called “registering.”)



[1]Direct Fire,”https://en.wikipedia.org/wiki/Direct_fire.

[2] “Direct Fire,” https://en.wikipedia.org/wiki/Direct_fire and “Glossary of Useful Terms,” : http://www.gutenberg-e.org/mas01/mas12.html.

 

Illustration source: Source: http://www.gutenberg-e.org/mas01/mas12.html

Joe Cabadas

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JCab747
March 10, 2019 - 10:43am

Spotters

A forward observer is critical when it comes to directing indirect artillery fire. This observer can be airborne, a satellite, a robot, a remote sensing device, a drone, or a person. The spotter’s job is to provide real-time information to artillery units so they can hit their targets.

Remote sensors can also act as spotters. For example, a seismic sensor post could detect enemy troop movements and opposing artillery fire and can be used to triangulate on an area. In game use, characters using such a remote system to target artillery fire receive an initial -15 percent penalty modifier.

As the spotter provides more information, the artillerist can add +5% to his successrate to a maximum of +20% bonus.

Joe Cabadas

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JCab747
March 10, 2019 - 10:51am

Time on Target

It was long discovered during the ancient wars of the Humans, Yazarians and Vrusk that most casualties in an artillery bombardment occur within the first few seconds when troops are in the open. Once the initial rounds hit, soldiers go prone on the ground or take cover. This dramatically reduces deaths and injuries due to shrapnel or high-explosive blasts.

As a result, artillery units learned how to fire their weapons in an order so that all their shells would hit a target at the same time and inflict the most damage possible. [1]

Large cannons as well as howitzers are capable of using time on target attacks, firing multiple shots at different elevations, speeds and timing so they will arrive at the target area at aboutthe same time.

Large cannons can fire up to three TOT shots, howitzers can fire five TOT shots, and railguns can fire up to six such shots.

A player must declare that they are using a TOT attack, up to how many shots they are firing in this manner, and write down the locations on the map that the shells are aimed at. The shells will all arrive on the same turn after the last one is fired.

TOT Usage. Large cannons have a rate of fire of one shell every two turns (1/2). It will take 6 turns for a large cannon to fire three shots for a TOT attack.

A howitzer has a ROF of one-fourth (1/4) so it will take 20 turns for it to fire its last shell in a TOT attack. A railgun has a ROF of one per turn so it will take 6 turns for it to fire its last round in a TOT attack.

How long before an artillery shell hits? A number of factors come into play in the modern world to determine how long it takes for anartillery shell to reach its target from the gun that fired it. Such factors include gun speed, the angle and gravity.

For game purposes, assume that all artillery shells hit a target that it takes 1 second for an artillery shell to travel 1 kilometer. So, if the target is 6 kilometersor less from the gun, it will be hit the same turn the round was fired unless the artillery unit is using a Time on Target attack. For every 6,000 meters of distance the target is away from the gun, add a turn before the shell hits.[2]

Enemy units with radar or other scanners can detect incoming artillery rounds, which will allow them to sound an alarm so soldiers can take cover, turn on inertia screens and activate anti-missile or anti-artillery lasers. (Note, sound travels 1,988 meters per game turn, so an artillery unit can be heard firing up to two kilometers away during the same turn.) Any ready counter-batteries may then fire in retaliation even before the first artillery shells in a TOT attack hit their targets. 



[1]“Time On Target,” https://en.wikipedia.org/wiki/Time_On_Target

[2] Adopted from: Grining, Peter. “Artillery in 2300AD,”http://www.users.globalnet.co.uk/~dheb/2300/Articles/PG/PGArt.htm



 

This illustration shows how time on target (TOT) is used so that the artillery munitions will arrive at the target about the same time. The artillery unit has fired six different shots at different elevations, speeds and timing so they will arrive at the same turn. Source:https://en.wikipedia.org/wiki/Time_On_Target

 




Joe Cabadas

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JCab747
March 10, 2019 - 10:54am

Counter-Battery Fire

When an artillery unit fires, not only will it make a tremendous sound (assuming it is used on a planet with an atmosphere), which will provide a warning to any nearby opponents, but its shells are visible on radar. For each round fired by an artillery unit, it gives the enemy a vague idea where the shots are coming from, permitting them to fire back at that location. Basically, a counter-battery radar would act as a forward observer.

Game use. Use the indirect fire rules. For each round fired by an enemy artillery unit, the counter-battery receives a +5% bonus to zero in on the attacker’s location.

The only way to avoid counter-battery fire is to relocate an artillery piece between shots. Otherwise,  stationary artillery units are dead artillery units.[1]

Anti-Aircraft Mode

Artillery weapons – cannons, howitzers and railguns – can be used in an anti-aircraft mode. To do this, they must be mounted in a manner that allows them to shoot upwards, such as a universal turret. 


They will fire standard or high explosive shells with proximity fuses. Most other specialized munitions are not useful against aircraft, though one could imagine the nasty effects a tangler explosive may have against an aircar’s engines. 


These guns have an additional -15 percent to hit a flying aircraft, however. A “near miss” – within a roll of “5” from the to-hit number, means that the enemy aircraft was in the secondary blast area and will take damage that way. Need to add more info. Railguns versus assault shuttles and landing ships?



[1]“Artillery Development Update,” https://aw.my.com/us/artillery-development-update

Joe Cabadas

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JCab747
March 10, 2019 - 1:25pm
The artillery rules should also include information on how many crew members are needed to fire one of these weapons, such as the howitzer.
Joe Cabadas

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JCab747
March 11, 2019 - 8:20pm

 

Cannon, Small

Cannon,  Medium

Skill:

Artillery

Artillery

Cost:

4,000 Credits

6,000 Credits

Weight:

40 kilograms

80 kilograms

Hard Points:

2 (medium)

4 (large)

Rate of Fire:

1/2

1/2       

Damage:

8d10

12d10

Ammo:

20 shells

15 shells

SEU:

N/A

N/A

Defense:

Inertia

Inertia

PB:

0-150 m

0-300 m

Short:

151-300 m

301-600 m

Medium:

301-600 m

601-1,200 m

Long:

601-1,000 m

1,201-2,000 m

Extreme:

1,001-2,000 m

2,001-3,000 m

Cannons have a single, long barrel and fire single shells at high rates of speed. The impact of the shell is impressive. On smaller vehicles, cannons tend to “rock” the vehicle backward when fired. They are often fired as indirect weapons, but can also be fired directly at a target. If the cannon is too close, it can get damaged or destroyed by its own shell. These weapons can also be fired at aerial targets, but often that requires changing to a different type of ammunition.


 

 

 

Cannon, Large

Howitzer

Skill:

Artillery

Artillery

Cost:

10,000 Credits

25,000 Credits

Weight:

160 kilograms

350 kilograms

Hard Points:

8 (large)

10 (large)

Rate of Fire:

1/2

1/4       

Damage:

3d10 x 10

7d10 x 10 + 50

Ammo:

10 shells

10 shells

SEU:

N/A

N/A

Defense:

Inertia

Inertia

PB:

0-600 m

--

Short:

601-1,200 m

--

Medium:

1,201-2,400 m

200-3,000 m

Long:

2,401-5,000 m

3,001-7,000 m

Extreme:

5,001-10,000 m

7,001-15,000 m

Joe Cabadas

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JCab747
March 11, 2019 - 8:19pm

Railgun (Gauss Cannon)

Skill:

Beam or Artillery Weapons

Cost:

80,000 Credits

Weight:

500 kilograms

Hard Points:

12 (large)

Rate of Fire:

1

Damage:

8d10 x 10

Ammo:

1,000 SEU drum plus 50 rounds

SEU:

20

Defense:

Inertia

PB:

--

Short:

0-1,000 m

Medium:

1-10 km

Long:

10-150 km

Extreme:

150-350 km

 

The precursor to portable gauss rifles, the railgun is an artillery weapon that has beam technology characteristics. It uses an electromagnetic launch system instead of gunpowder or a propellant to fire an armor-piercing projectile up to Mach 10. It delivers its munitions with a range and destructive force that far exceeds conventional weapons. Generally this weapon is unavailable except for well-equipped planetary militias, the UPF Landfleet or the richest mega-corporations.

Joe Cabadas