[[[Playtest Focus]]] Missiles II

MongooseMatt

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Staff member
We had some really good input from you chaps on the missile rules presented yesterday - this new thread presents a revised set of mechanics.

Please read through them carefully (there is a little less text than before, usually a good sign!), but the basic changes are listed here: http://forum.mongoosepublishing.com/viewtopic.php?f=149&t=118010&p=894990#p894990




Missiles

[[[ Replace text on pages 161-162 ]]]

Missile Combat
Unlike most weapons which travel at or close to the speed of light and so hit enemy ships almost instantly, missiles take time to cross the gulf of space. However, despite this drawback, missiles are capable of doing a great deal of damage when they hit an enemy ship.

Launching Missiles
Missiles cannot be used against targets within Adjacent or Close ranges, as there is not enough time for them to obtain a solid lock and safety protocols are engaged to stop the, turning back and hitting their own launch vessel.

Missiles are launched in salvos. A salvo is all the missiles launched by a ship against a single target in the same combat round. This could be a single missile from one turret or dozens from multiple turrets or bays (see High Guard for more information on weapon bays).

Missile salvos effectively have a Thrust of 10 and will reach their target a number of combat rounds after they have been fired, as shown on the Missile Flight table.

Missile Flight
Range Rounds to Impact
Close and Short Immediate
Medium 1
Long 2
Very Long 3
Distant 5

Note that while missile salvos can be fired at Distant ranges, the attacking ship must have detected its target before they can be launched. Given the limited information that can be gained from sensors at this range, friendly fire incidents may be common among Travellers who are too trigger happy with their missiles.

If a missile has not reached its target within 5 rounds, it will run out of fuel and become inert.

Countermeasures
Combat involving missiles creates a very tense atmosphere. The target spacecraft will likely have detected the launches and its crew will have several anxious minutes to watch the blips on their sensor screens gradually get closer and closer.

Fortunately, the crew need not be idle as they await their destruction as there are several countermeasures that can be taken against incoming missiles.

Electronic Warfare: A Traveller performing sensor operator duties on a spacecraft can use the Electronic Warfare action to destroy or misdirect incoming missiles before they impact his vessel or another ship within Close range.

The sensor operator must succeed at a Difficult (10+) Electronics (sensors) check (1 round, INT) in order to destroy or render inert incoming missiles within a single salvo. The Effect of this check will immediately remove that many missiles from the salvo.

Electronic Warfare may be performed upon a salvo multiple times over several rounds, with the effects being cumulative. However, a salvo may only be subjected to Electronic Warfare once per round, no matter how many sensor operators are available.

Flee: A spacecraft under missile attack may simply turn around and engage its manoeuvre drive, thrusting away from the missiles. Missiles are extremely long-ranged weapons and so it is not normally possible to outrange a missile in this way, but it can perhaps buy enough time to prolong electronic warfare or make a jump.

Point Defence: Finally, just as a salvo is about to strike, gunners may engage in point defence, as detailed on page 160.

Missiles and Targets
When a missile salvo reaches its target, the missile makes an attack roll as normal. However, the Gunner skill of the Traveller(s) that fired the salvo is not used as a DM.

Instead, the number of missiles remaining in the salvo greatly affects their chances of making a successful attack. Apply DM+1 to the attack roll for every full 5 missiles in the salvo.

Note that missiles almost always have the Smart trait (see page 75). For missiles, use the TL of the missile itself or that of the attacking ship, whichever is greater.

Finally, missiles launched at Distant range expend most of their fuel just reaching their target, leaving little to counter the target’s manoeuvres. Missile salvos launched at Distant range suffer DM-6 to their attack rolls.

Impact
If an attack roll for a missile salvo is successful, the target will sustain damage. If the salvo consists of just a single missile, this is performed as normal.

However, if a salvo consists of more than one missile, do not add the Effect to the damage caused. Instead, add 1D of damage for every point of Effect. This represents the increased damage of multiple missiles striking their target.

Variant Missiles
High Guard introduces different types if missiles that are more accurate, carry more fuel or are faster, but these rules suit all missiles included in this Core Rulebook. If a ship launches different types of missile at the same target in the same round, then all the missiles of each type are counted as a different salvo.




[[[ Replace text on page 160 ]]]

Point Defence (Gunner)
Using a turret-mounted laser (beam or pulse), a gunner can destroy incoming missiles. Note that a weapon used for point defence cannot be used to make attacks in the same combat round, and vice versa. Point Defence may only be performed against missile salvos (see page 161) as they are about to make their attack roll against a target – missiles are too small and too fast to be targeted at greater ranges. A gunner may only attempt Point Defence against once every round.

The gunner must succeed at a Gunner (turret) check against any missile salvo that is about to make its attack roll against his spacecraft. The Effect of the check will remove that many missiles from the salvo.
 
Instant reaction without thinking it through:

5 missiles give Attack +1, hence Effect +1, hence +1D damage. That is not enough?
Many missiles still ignore armour.

Smart effect should be TL of missile, the ship that launched half an hour before has no influence. The ship might be destroyed or Jumped out when the missile attacks.
 
I wonder if similar system can be drafted for firing the same type of beam/projectile weapons?

I.e. instead of firing 5 turrets, fire all five as as salvo. I haven't put much thought in it, perhaps it might not be as easily applicable.
 
This is going in a direction I was intending to support before this new post came along.

Yep, get the electronic warfare roll right out of the combat sequence, making that an individual action roll on the player's turn. They can choose to do a single action like jamming communications, breaking a lock, attacking missiles per operator and make that defined as a separate action away from the combat calculations.

The rest should be as simple as possible which I think this has done. One roll per gunner for point defence I was thinking is correct otherwise it runs out of control.

What I'm not so sure about is the upgrade from a single missile in a salvo. The logical basis could be something for a triple turret and if possible build the paradigm around +1DM / 3 missiles. +1 dice of damage/ 3 missiles is not out of line in terms of a rational result. 3.5 hull points for 3 missiles is not a deal breaker I think at a first stab. The tricky part is the number of missiles that get through vs. the actual damage and will mull this over more.

What the salvo effect does though is make the smart trait pretty much redundant. You're never calculating how many missiles missed from a major salvo. It's hit more, or hit less. I guess they all just go off in one big bang ;)
 
AnotherDilbert said:
Smart effect should be TL of missile, the ship that launched half an hour before has no influence. The ship might be destroyed or Jumped out when the missile attacks.

My thought here is that the firing ship needs to plot a 'missile firing solution', where its TL would help. Happy to go either way on this, what does everyone else think? Basing it on the higher of the two would also stop us faffing around with multiple TLs on missile types...

arcador said:
I wonder if similar system can be drafted for firing the same type of beam/projectile weapons?

That has crossed my mind for the capital ship/fleet combat :) However, lets get missiles sorted, and then we can expand outwards.

Chas said:
What I'm not so sure about is the upgrade from a single missile in a salvo. The logical basis could be something for a triple turret and if possible build the paradigm around +1DM / 3 missiles. +1 dice of damage/ 3 missiles is not out of line in terms of a rational result. 3.5 hull points for 3 missiles is not a deal breaker I think at a first stab. The tricky part is the number of missiles that get through vs. the actual damage and will mull this over more.

This, I suspect, will be the nub of these mechanics - at what rate we want to scale up the number of missiles vs. DMs, and whether it should indeed be linear. Very much want to hear opinions on this.
 
Update examples from the older tread:

Very Long range, two identical ships shooting at each other.

Free Trader:
Two Free Traders with two turrets with 2 missile racks and a laser each.
Civilians so less skilled gunners and less software.
Fire 4 missiles, EW, EW, EW, PD, PD, Attack, Damage
Launch is no roll?
EW is 2D +1(skill) +1(INT) -2(Sensor) -10(Difficult) ≈ -3 Effect, so don't...
PD is 2D +1(skill) +1(DEX) -8(Average) ≈ 1 Effect
PD kills 2 missiles, 2 left in salvo
Attack is 2D +1(smart) -2(EvasiveAction) ≈ 7 +1 -2 -8 ≈ Effect -2, rarely hit.
Damage is 4D +0D(effect) -3(Armour) ≈ 11 around 15% of structure, so a crit.
Multiple warhead missiles will likely kill ship in a few rounds, if they could hit.
You toss out MCr 1 worth of missiles for next to no effect, not for traders.

Patrol Corvette: two triple missile turrets, two triple laser turrets
Better skill:
Fire 6 missiles, EW, EW, EW, PD, PD, Attack, Damage
Launch is no roll?
EW is 2D +2(skill) +1(INT) +0(Sensor) -10(Difficult) ≈ 0 Effect
PD is 2D +2(skill) +1(DEX) +2(triple) -8(Average) ≈ 4 Effect
EW + PD kills 8 missiles, very rare to let one through
Attack is 2D +1(many missiles) +1(smart) -2(EvasiveAction) -2(Evasion software) ≈ 7 +2 -4 -8 ≈ Effect -3, rarely hit
Damage is 4D +0D(effect) -4(Armour) ≈ 13, almost 10% of structure so might be a crit

Military optimised Patrol Corvette: three triple missile turrets, one triple laser turret
Fire 9 missiles, EW, EW, EW, PD, Attack, Damage
Launch is no roll?
EW is 2D +2(skill) +1(INT) +6(Sensor) -10(Difficult) ≈ 6 Effect
PD is 2D +2(skill) +1(DEX) +2(triple) +1(Accurate) -8(Average) ≈ 5 Effect
EW + PD kills 23 missiles, so no chance of any missiles remaining.
Attack is 2D +1(many missiles) +1(smart) -2(EvasiveAction) -2(Evasion software) ≈ 7 +2 -4 -8 ≈ Effect -3, rarely hit
Damage is 4D +0D(effect) -4(Armour) ≈ 13, almost 10% of structure so maybe a crit


2000t semi-military ship
2000t = 800 struct. 1 Large Missile bay + 19 Laser turrets. Better computer. Good sensors. Heavy Armour. MCr ~1000.
Fire 120 nuclear missiles, EW, EW, EW, 19 * PD, Attack, Damage
Launch is no roll?
[ 3 rolls] EW is 2D +2 (skill) +1(INT) +6(Sensor) -10(Difficult) ≈ 6 Effect
[19 rolls] PD is 2D +2(skill) +1(DEX) +2(triple) +1(Accurate) -8(Average) ≈ 5 Effect
EW + PD kills 3*6 + 19*5 = 113 missiles, so few missiles remaining.
[ 1 roll] Attack is 2D +1(~7 missiles) +1(smart) -2(EvasiveAction) -3(Evasion software) ≈ 7 +2 -5 -8 ≈ Effect -4, very rarely hit
[ 1 roll] Damage is 6D +0D(effect) +0(Effect) -15(Armour) ≈ 6, negligible damage
Rolling PD is getting out of hand.
A MCr 1000 ship is launching MCr 60 worth of missiles each round, worth it for a few rounds, but not 10 - 20 rounds?

Conclusion
Missiles have large problems hitting without TL advantage or massive salvoes.
Salvoes from small ships (400t) are wiped out by good EW. Missiles with ECCM would ameliorate this.
The treat of missiles force you to have good missile defences.
The system is to swingy, bad defences will kill almost no missiles, good defences will kill all missiles.
 
AnotherDilbert said:
Missiles have large problems hitting without TL advantage or massive salvoes.
Salvoes from small ships (400t) are wiped out by good EW. Missiles with ECCM would ameliorate this.
The treat of missiles force you to have good missile defences.
The system is to swingy, bad defences will kill almost no missiles, good defences will kill all missiles.

Okay, missiles with ECCM will be going into High Guard, but not in Core. TL will also become a thing (either instead of specific ECCM or as well as, depends if we roll them in altogether), but probably not in Core either. However, in Core we do not really have good EW (other than operator skill), so this should balance until High Guard comes along with the extra rules?

So, we will make TL a thing (in High Guard) and, I am thinking, we reduce the cost of missiles so large salvos become viable.

I am also thinking that PD should be a Difficult roll... what are people thinking here?

Then the next thing to worry about is going to be missile numbers vs. DM on damage dice. What does everyone think on that?

Also worth pointing out, missiles get better at shorter ranges.

The other thing I was looking at was to allow missiles to be targeted at Close and Adjacent ranges, but to remove the Smart trait when they do so, along with any possibility of EW. What would everyone think of that? Could make close range attacks with missile bays absolutely savage...

Everyone else having as much fun with this tinkering as I am? :)
 
The same 2000t ship. We fire a second salvo from another ship, so the PD is already used:
2000t = 800 struct. 1 Large Missile bay + 19 Laser turrets. Better computer. Good sensors. Heavy Armour. MCr ~1000.
Fire 120 nuclear missiles, EW, EW, EW, 0 * PD, Attack, Damage
Launch is no roll?
EW is 2D +2 (skill) +1(INT) +6(Sensor) -10(Difficult) ≈ 6 Effect
EW + PD kills 3*6 = 18 missiles, 102 remaining.
Attack is 2D +20(~100 missiles) +1(smart) -2(EvasiveAction) -3(Evasion software) ≈ 7 +21 -5 -8 ≈ Effect 15, auto crit
Damage is 6D +15D(effect) -15(Armour) ≈ 60, less than 10%, armour is basically ignored.


Attack is too high?
Damage is too low?
 
I do like the fact that a weapon is only allowed to be used for either used for point defense, or offense...Makes sense to me.

as for firing at close and adjacent ranges stripping away the smart trait.

I've mentioned it earlier, but a simple dumbfire rocket would be a good add, short and adjacent range only cheaper than missile, with nearly the same punch...for those traders on a budget, or someone who has to arm a few hundred fighters.

A trader could carry a handful of expensive missiles, then switch to cheaper rockets when the fight gets up close and personal.
 
msprange said:
The other thing I was looking at was to allow missiles to be targeted at Close and Adjacent ranges, but to remove the Smart trait when they do so, along with any possibility of EW. What would everyone think of that? Could make close range attacks with missile bays absolutely savage...

Sound reasonable. Instead of Smart it could be Gunnery skill since at such sort rang it would be more "firing in the right direction" than "missile manoeuvering".
 
With this system large ships, e.g. battleships, will not bother with armour. If an attack hits it will be _lots_ of dice damage and armor will be irrelevant. I think that is, ahem, undesirable.
 
Yeah, armour is bugging me, and I don't think it can be ignored :)

My first thought is that armour should deduct a proportion of the damage dice added from Effect or (perhaps better) it is armour that dictates the ratio of missile numbers vs. Effect-added damage dice.

That would need a table, which is not great, but might otherwise solve this issue quite nicely.

Anyone see any issues with that?
 
We want to simulate (4D +(small Effect) - Armour) * # of missiles, except that that is too much damage, right?

Using a mechanism of (4D +(small Effect) - Armour) * N is the simplest way to achieve that. N could be (# of missiles hitting)/3 or 5 (rounded up). This could be bearably simple to describe and calculate?

Any other system would be prone fall apart with small or large numbers, so prone to gaming the system.
Allowing a massive effect because we fired lots of missiles will make this system pall apart.
 
AnotherDilbert said:
Any other system would be prone fall apart with small or large numbers, so prone to gaming the system.
Allowing a massive effect because we fired lots of missiles will make this system pall apart.

Well, we can have a little leeway here (because Big Explosions), and I would tend towards simplicity and speed rather than making sure we round up every calculation. So...

I was thinking of something as simple as this (actual figures will need adjusting).

Against Armour 11-15, DM+1 (on the damage dice) for every 10 missiles.
Against Armour 6-10, DM+1 (on the damage dice) for every 6 missiles.
Against Armour 1-5, DM+1 (on the damage dice) for every 3 missiles.

Something like that. Basically greatly limiting the damage potential at the high end, but not screwing over small ships when there is just a couple of missiles in the air. And if we might just be able to translate those rules straight across to capital ship/fleet combat. However, one step at a time (need to figure out what fighters do as PD in fleet combat for a start...).

How would all that look?
 
Simulating to hit could be simple.

The Basic system we want to simulate is: Each missile rolls attack. At 8+ (no DMs) about 40% hit, so if I fire 10 missiles 4 would hit.

To simulate that we could say: Roll Attack for the salvo. 50% of the missies hit, for each Effect add or subtract 10%, max 100% (50%+10%*Effect). So at 8+ (no DMs) if I roll a 7 Effect is -1, so 50%-10% = 40% hits, so if I fire 10 missiles 4 would hit.

There is a bit of calculation, but it is fairly simple and doesn't fall apart with small or large numbers.
 
AnotherDilbert said:
if I fire 10 missiles 4 would hit.

There is a bit of calculation, but it is fairly simple and doesn't fall apart with small or large numbers.

But we are then making (potentially) lots of damage rolls - that is what I want to avoid...
 
You are trying to make the system simpler. From a mathematical standpoint you are making the system more complex. Each time you add a little fudge to parry corner cases, you add complexity, increasing the possibility of strange behavior in some other case.

In a system that allows 10t to 1 000 000t ships to fight non-linear system are a bad idea, they will fall apart at either 10t or 1 000 000t or both.
 
msprange said:
But we are then making (potentially) lots of damage rolls - that is what I want to avoid...
Roll damage once and multiply by number of missiles. I can guarantee that the player who roll a high damage roll and gets to multiply with 10 will not be dissatisfied.
 
AnotherDilbert said:
Roll damage once and multiply by number of missiles. I can guarantee that the player who roll a high damage roll and gets to multiply with 10 will not be dissatisfied.

Fully agree with that! How would you factor armour in on this system?
 
AnotherDilbert said:
We want to simulate (4D +(small Effect) - Armour) * # of missiles, except that that is too much damage, right?

Using a mechanism of (4D +(small Effect) - Armour) * N is the simplest way to achieve that. N could be (# of missiles hitting)/3 or 5 (rounded up). This could be bearably simple to describe and calculate?

Any other system would be prone fall apart with small or large numbers, so prone to gaming the system.
Allowing a massive effect because we fired lots of missiles will make this system pall apart.
 
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