Incoming!! But how fast?

[san*klass]

After a thirty year break I am re investigating CT as a campaign possibility. To that end I bought The Traveller Book last autumn, and have been slowly digesting it's wonders afresh.

However, I have hit a snag with the starship rules, that I hope the learned members of this forum can kindly answer. I imagine that this may have already been addressed here, and so apologies if we are covering old ground!

My problem is with both laser and missile weapons, as follows:-

1) I understand that beam lasers are easier to hit with and pulse lasers do more damage, but I can't seem to find any rules that put numbers to this statement. +2 to hit for beam and +2 damage for pulse are floating around my memory, but I am uncertain if that is right.

2) The missile rules seem to indicate that missiles move just as ships do, but I can't find any indication as to how many G's of thrust they have.

I have read and reread the space combat and ship design rules, but can't find an answer to either question anywhere. Can someone please help??

 

[ffilz]

Pulse lasers are covered by the errata:

Page 29, Laser Fire, Pulse Lasers (omission): Pulse lasers are less accurate but more powerful than beam lasers. A pulse laser fires with a DM of –1 to hit; however, if it hits the target suffers two damage rolls instead of one.

On Google+ there was a discussion of missiles. Mayday has missiles getting 6 turns worth of 6G (annotated as 6G6).

 

[kilemall]

SS3 precisely defines the standard Traveller missile as a homing missile rated 5G6, meaning it can go 5Gs for 6 turns.

The damage is different, 2 hits plus variable impact and warhead design rules, for your purposes unless you feel the need to put on a lot of missile chrome and implement SS3 the standard 1d6 should be fine.

 

[aramis]

After a thirty year break I am re investigating CT as a campaign possibility. To that end I bought The Traveller Book last autumn, and have been slowly digesting it's wonders afresh.

However, I have hit a snag with the starship rules, that I hope the learned members of this forum can kindly answer. I imagine that this may have already been addressed here, and so apologies if we are covering old ground!

My problem is with both laser and missile weapons, as follows:-

1) I understand that beam lasers are easier to hit with and pulse lasers do more damage, but I can't seem to find any rules that put numbers to this statement. +2 to hit for beam and +2 damage for pulse are floating around my memory, but I am uncertain if that is right.

2) The missile rules seem to indicate that missiles move just as ships do, but I can't find any indication as to how many G's of thrust they have.

I have read and reread the space combat and ship design rules, but can't find an answer to either question anywhere. Can someone please help??

#1 — See TTB page 74, top left. Attacker's DM's table. 2 hits but –1 to hit.

#2 — it's missing from TTB. It's also missing from CT-1977 and CT-1981.

So, let's turn elsewhere.

So we look at contemporary partner games... and later supplements.

6G6 (6G for 1 turn) is the default in Mayday, but mayday turns are 2 hours long (7200 seconds) - TTB's are 1000 seconds. I've always used 6g18 (6G for 3 turns) in CT. A mechanical equivalence conversion would be 6G43... but that doesn't jive with the later SS3-Missiles...

The standard missile in SS3 is 5G5 limited burn homing.

Everyone I played with before SS3 had the standard as a 6g18 (but we said 6G, 3 turn endurance)... I know we looked at the AIM-9 Sidewinder... as it was the only thing we had good stats for.

The AIM-9 had 4000lbs for 2.2 seconds, and massed 70 lbs... 57G's for 2.2 sec.
We simply reverse engineered to get 5.7 for 22, or 0.57 for 220... then realized , "Hey, it's TL6... Let's multiply"...

Doing the same math we did back then...

initial AIM-9 data	=4000 * 2.2 = 8800 lb•s at TL 6
We found a reference for 10% reduction in mass per TL. We flipped that, got 111% (=10/9) per TL, 3 TL's minimum to get the TL9 missile...	=8800 * ((10/9)^3) =12071.33058984911
multiplied that by 110lb (50kg, mass of a traveller missile) over 70lb (mass of an AIM-9)	=12071.33 * 110/70 =18969.233 lb•s
Divided by 110lbs to get G•s (gee seconds)	=18969.233 /110 = 172 G-seconds.

[tc=2]Promptly realized that didn't work at all, because it gave us way too little, and went searching for striker[/tc]

Striker's Tac Missiles and Drone Missiles are the key.
A CPR warhead (at 1/20 the standard weight, as per Tac Missiles).
Scale is 30 sec... we need 1000/30=33.3 turns per space turn.
10cm warhead is standard. that's a base of 30kg/round.
We have a cap of 50 kg.
Oh, wait, the warhead is, per striker, supposed to be 15cm.
Batteries are in MW•S; the endurance is MW•S * 10000 / 50 kg in seconds. we need 1000 second turns, to MW•S * 0.2 = CT Turns.
I'm rounding up to the next 20th (0.05) kg, and next whole credit.

1.5	9	HEAP warhead 10cm
3	18	HEAP warhead 15cm
1	300	homing guidance
2	5000	1G of gravitic drive
2.25	844	TL9 Battery, per G (2.25 MW•S/kg)
1.7	893	TL10 Battery, per G (3 MW•S/kg)
1.45	979	TL11 Battery, per G (3.5 MW•S/kg)
1.25	1062	TL12 Battery, per G (4 MW•S/kg)
0.5	1500	TL13 Battery, per G (10 MW•S/kg)
0.35	1750	TL14 Battery, per G (3.5 MW•S/kg)
0.2	2000	TL15 Battery, per G (3.5 MW•S/kg)

[tc=3]important elements of the missiles[/tc]

So, out TL 9 missile options...

3	18	HEAP warhead 15cm
1	300	homing guidance
12	5000	6G of gravitic drive
33.75	12660	TL9 Battery, 15 G•Turn (2.25 MW•S/kg)

So 6G15 (2.5 turns) of gravitic homer... At TL9, per MT, it's going to be reduced to 1/10 effect past 10 diameters.
The TL10 version won't be, and will be more expensive (but may reduce battery costs by using TL9 ones at 10% cost reduction...)

A TL 9 gravitic deep space missile is going to have other issues.

Note SS3 is rather bolluxed either way. It doesn't match ANYTHING else in the system, and has major errors in the tables. Don was rewriting it...

 

[kilemall]

Aramis I looked this up, I didn't want to get into the full chrome of it but SS3 Traveller homing IS 5G6, proximity detonation, warhead HE 10 kg, mass sensing, continuous burn.

And the expression 5G6 means 5Gs, 6 burns- 6 times it can fuel a full 1000 second turns burn at 5Gs. Or, potentially 30 1-G burns.

The current FFE CD-ROM set of original books includes both the as-published SS3 and the revisions edition authorized by Miller and captured by Don McKinney, complete with redone tables. The missile statement in the revision jibes with the errata except for a few costs and the weight numbers, and the tables don't entirely match. Not sure what that means ultimately or which is the more accurate.

The rest of your post are all arguable points I'm not going into, but I think it's important to accurately reproduce the rule, even as we argue to trash it.

Among other things, the problem with this missile definition is that it specs mass homing, which means it's not vulnerable to ECM (radio/radar based). This conundrum is what got me going on the alternative sandcaster load thread in the first place.

Another problem is they specced continuous burn, which effectively is a one turn missile as it misses otherwise if the target is not in the homing range. Well I should say technically it will 'intercept' within 25mm and not be able to impact after the first turn. But on a practical basis, it's EASY to put on 2500 km of space between current position and an incoming missile's course.

So why pay and buy more then 5G1/5G2, use the money to put a bigger/more effective warhead on it or at least make it cheaper? In that sense, your limited burn statement makes much more sense for how the missile is classically regarded as performing.

Continuous burn therefore for cheap dogfighting missiles at one turn range, limited for medium range general work, and discretionary for artisan/long range work.

Heh, if people are using grav/contragrav technology, does that sort of drive by definition spoof a mass sensing missile?

Somehow I had missed the contact detonation x2 multiplier was in addition to the warhead but separate from the impact hits.

Whole thing is just that much more nuanced, especially as ECM'd missiles can still do impact damage even after their warhead/detonators are neutered. Always pays to have a reread with fresh eyes, especially on this set of rules.

 

[kilemall]

Ok, I'll spec my take on what the classic Traveller homing missile should be in SS3, with a target cost of 5000 Cr, vulnerable to ECM as per the classic rules, and a possibility of the 1d6 result as much as possible.

We want this thing to have range AND flexibility but not Benz prices, so limited burn AND radio guidance are musts (since we are going to be using radar anyway for the ECM vulnerability).

Let's retain the 5G speed, seems reasonable to allow the speedsters to potentially get away but hit pursuers or slow vessels, and figure out burn capacity as we go along. May be able to undersize the missile and reduce fuel cost that way.

HOLY COW, those fuel costs are harsh on our budget! A straight translation of continuous 5G6 to limited translates to 5G1- pointless, might as well design it to be a dogfighting one turn missile and put the money into 6Gs.

Ok, we really do need to bring the weight down.

Well the switch to radio receiver from mass sensor saves us 600 Cr, but not weight.

Well here is a radical thought- we'll just toss the warhead out, make it an impact missile only. Doesn't require a detonator either since there is no warhead TO detonate.

Oh, and that weight drops dramatically too with the limited burn spec, may still pull this off. If I can make the missile 25 kg, then I only need half the fuel to achieve 5G6.

Radio Receiver, 1 kg 100 Cr
Limited Burn Propulsion, 5G3, 13 kg 4500 Cr

Well heck, I'm 11 kg under budget, let's do it right, but bargain basement ethos.

We'll go Command Detonation, that gives our heroes the option of impact OR proximity, and a standard HE warhead.

Command Detonator 1 kg, 200 Cr
HE Warhead 10 kg, 500 Cr

For a total cost of 5300 Cr. But actually this would cost less due to the TL rules.

TL9 we get full credit 80% cost for the detonator and radio 60 Cr, HE warhead 50 Cr so 5190 Cr. TL10 we get 80% for most and 10% on the propulsion so 4690 Cr. TL11 max savings, 4240 Cr.

Shop smart. Shop high tech industrial worlds.

Heh, by the Varying Payload multiplier rules for having a half-sized missile, with a 5G3 package on a 25kg weight I should give this missile a 10G6 rating. Hoo doggie, that's a weapon system!

Well, this fits our standard missile not counting the speedster aspect, as ECM could neuter it, it can be command detonated for 2 hits or set for contact and 4 hits, and impact variable rules can add on variable amounts of damage, or be the sole source of hits.

The smarter detonation system might be contact, damage even if the missile is ECM'd on the first turn, but the idea is to recreate the typical homing missile performance to include elimination by ECM roll.

One of these days I'll do the SS3 HG missile. Due to the Striker clues with the warhead Aramis cites, probably 4-5x the volume and therefore weight of a CT missile rack missile. Putting that much warhead and cost on it, these things should have greater range, punch, multiple sensors, intelligent detonators and full evasion. They should utterly terrify an ACS operator.

 

[mike wightman]

The rules for the pulse laser are in the Starter Edition of Traveller: -1 DM to hit, 2 damage rolls.

 

[aramis]

Aramis I looked this up, I didn't want to get into the full chrome of it but SS3 Traveller homing IS 5G6, proximity detonation, warhead HE 10 kg, mass sensing, continuous burn.

And the expression 5G6 means 5Gs, 6 burns- 6 times it can fuel a full 1000 second turns burn at 5Gs. Or, potentially 30 1-G burns.

Not in mayday, it doesn't. Nor in the versions of SS3 I've got on my HD.

 

[mike wightman]

I agree with Aramis - I don't think the 'errata' makes things better, I think it makes them worse.
The original interpretation of burns in SS3 matches Mayday's interpretation - so either the errata needs to be applied to both or the errata should never have been accepted.

 

[san*klass]

Many thanks to all for resolving this problem for me.

The only thing that concerns me is that p74 of my copy of TTB doesn't have the pulse laser rules quoted by Aramis. Mine is one of the Print on Demand copies, so I hope that nothing else has been omitted?

 

[mike wightman]

The pulse laser rules only ever appeared in full form in the CT Starter Edition, they were then copied across to the errata file.

 

[kilemall]

Not in mayday, it doesn't. Nor in the versions of SS3 I've got on my HD.

Agreed on Mayday, but I think Mayday was a simplified creature with huge time/distance ranges, I wouldn't expect the two to match exactly as the missiles would then end up with several times the range.

We gearhead nerds probably need to keep in mind that the different games, especially the early ones, should probably be taken within their specific design/effect intent and as general guideposts and works of 'development of game process'.

And then of course when we DO get mass gearhead nerdery in our rulesets, we complain it's too much work for too little effect. Poor Miller and Company can't win.

However, the errata WAS vetted by Miller, by Don, and so I would take that as a definitive rule which we should note even if we choose to ignore it.

Now if we both have the same material, but there is some misunderstanding on either your part or mine, let's go over it.

The rule states that the 5G6 spec breaks down as

• 5G is maximum Gs the missile can accelerate/alter course
• 6 is the number of G-burns of fuel the missile can make at maximum G.

The following sentences go over multiple cases, a 1G1 missile can go 1 G for 1 turn, the 3G3 example explains that the missile can only accelerate by 3G, can go 3G for 3 turns, but can also go 1 G for 9 turns or 2G for eight turns. Very little of that is errata.



So under that ruleset the 5G6 missile can be set for 1 G and 30 turns. Wouldn't be useful for combat, the sort of thing you might use as a probe, but it's technically possible.


Please explain if I have this wrong somehow.

 

[aramis]

Agreed on Mayday, but I think Mayday was a simplified creature with huge time/distance ranges, I wouldn't expect the two to match exactly as the missiles would then end up with several times the range.


Please explain if I have this wrong somehow.

Mayday is the precursor; SS3 was late in the process. The revision was in the last 5 years, and was almost purely Don, and don changed the meaning of a particular nomenclature because he disliked it.. and I do NOT have revised SS3. Not on the revised CD I got from Marc Christmas 2014, nor on the older one, nor on my HD from Don. The only references to don's changes are in the errata file.

The time difference... Mayday is 7200 second turns, with corresponding hex size; CT Bk2 is 1000 second turns.

Mayday nomeclature:
XgY
X maximum burns per turn
Y total burns available
each burn is 1 G for 1 turn.
A 1G18 limited burn missile is 18 turns at 1G
A 2G18 is 9 turns at 2 G,
A 3G18 is 6 turns at 3G, and so forth.
Seems kinda pointless? Well, it's not.
In addition to limited burn, there's discretionary burn missiles...
which can use less than maximum thrust.
So a 4G8 missile can be used for 0-4 G's on turn 1, then again on turn 2, and if fuel remains, on turns 3 and later. If it does 4G's on turns 1 & 2, it coasts thereafter.
So, on my car, it might read:

4g8 6 5 4
​

after a few turns...

One of the big problems with CT is that much of the newer stuff wasn't checked for compatibility with older stuff. Also, that Striker is essentially the vehicle design sequences for anything smaller than 10Td. (There's a reason MT was built on a striker foundation.)

Striker also gives us a reason why we can get stupidly long durations - gravitics are really really hyper efficient.

 

[whartung]

Every reference I've see of mGn is m is the rating of the engine, and n is the amount of fuel in Gs the unit has.

So, 6G6 is a 6G engine with 6 G turns of fuel. That mean it can burn all 6Gs in one turn, or, at the other end, 1G per turn for 6 turns.

Mayday is like this, TNE is like this.

I've never seen it suggested that a 6G6 missile has 36G's worth of fuel, 6 turns of 6G.

 

[kilemall]

The revised SS3 missiles are somewhat similar to Mayday, but each propulsion type plays radically differently.

I won't get into the Mayday characterizations of the missile as I really don't care for the time/turn/damage scale of that game to begin with, just the vector movement system to avoid minis/graph paper tracking.

Original SS3 gutshots missiles, 5G6 in that case means the missile could go 5G for one turn and 1G the next turn, that makes missiles short range dogfight weapons of questionable utility, really horrible. The premier example is a 3G12 missile, which can go 3Gs for 4 turns, 1 G for 12 turns, or 2 G for 6 turns.

Arguably that is 'more realistic' for reaction propulsion fuel use, but it makes for bad gaming. I recognized that when I first saw it in the 80s, and converted it right away to the <accel>G<turns> model.

 

[kilemall]

Every reference I've see of mGn is m is the rating of the engine, and n is the amount of fuel in Gs the unit has.

So, 6G6 is a 6G engine with 6 G turns of fuel. That mean it can burn all 6Gs in one turn, or, at the other end, 1G per turn for 6 turns.

Mayday is like this, TNE is like this.

I've never seen it suggested that a 6G6 missile has 36G's worth of fuel, 6 turns of 6G.

Revised SS3 is this way, and as I just posted, it was clear the darn things were useless at the original definition.

I mean useless. Pitiful. Not worth the rack space.

 

[whartung]

I recognized that when I first saw it in the 80s, and converted it right away to the <accel>G<turns> model.

So, you house ruled that 6G6 means that the missile can burn 6G of maneuver, over 6 different turns?

So under that ruleset the 5G6 missile can be set for 1 G and 30 turns. Wouldn't be useful for combat, the sort of thing you might use as a probe, but it's technically possible.

What ruleset? I have not read S3, but as I've said, I've never seen a mGn missile as having m x n G turns available, it's always been G rating of the drive, total amount of G Turns as Fuel.

Or are you saying the m x n interpretation is updated by errata?

Because in Brilliant Lances, and Battle Rider, both done long after Book 2, Mayday, and S3 follow the same interpretation. 12G12 is a 12 g drive with 12 total G Turns of fuel (not 144). That is, it can not maneuver at 12 G for 12 solid turns. I can for 1 turn.

Revised SS3 is this way, and as I just posted, it was clear the darn things were useless at the original definition.

I mean useless. Pitiful. Not worth the rack space.

Hardly worthless. They work fine as a stand off weapon, as they should. Consider this quote from Battle Rider:

Note a ship can have more missiles in flight at one time than it can control. For example, a ship could launch a number of missiles, a few at a time, and maneuver them to form a picket line in front of the ship. As it launched more missiles, the missiles were already in position in the picket line would be allowed to go uncontrolled, and would coast along ahead of the ship, forming a screen until they were needed.

The problem you're portraying is that the missile don't work like, perhaps, a Standard Missile launched from a ship after a plane. Where you see the exhaust trail arcing as it chases after its target. The idea that you're launching missiles from across the map and they go chasing down ships.

Missile in Traveller are deployed with the ships vector, the 6G6 moniker gives you the engagement range. Toss the missile out and let it coast. On any turn that a target gets within 6 hexes (which is a pretty large hunk of the map), that missile burns all 6 of its Gs and attacks the target.

Similarly, a ship can start closing on an enemy ship, they launch missiles over a couple turns, but otherwise does not maneuver. Much like a sand caster, there's a 6 hex bubble around the ship that should deter any intruder trying to approach. You want to get to me? You get to come through my missile screen.

A 3G12 missile is much more maneuverable, having several opportunities to correct it's course as it homes in on a target.

Finally, in BL/BR, the missiles are 12G12, a 12 hex radius -- 360K km, which is just a crazy range. Because TNE is not limited to 6G M Drives like CT is.

Because that's how the game works. You move your ship, then I get to move my missiles. Which means I get to move the "future point" N hexes (based on G's burned) to it's "new" future point. If you're within 6 hexes of my missile future point, I simply move my future point on to your ship, and fireworks ensue.

So, yea, they take some planning, but they're hardly useless.

 

[whartung]

So I found S3 Revised on the FFE CD.

And, yea, they basically say what you're saying. 6G6 is 36G turns of fuel on the missile.

I just find it curious that they had this insight in 1986, but, apparently, didn't use it in either BL or BR. The fact that they expanded the missiles to 12G was no doubt to make them more dangerous.

Just a serious change in the game, in behavior, operations, and cost, and then they "undid it" in TNE.

 

[aramis]

So I found S3 Revised on the FFE CD.

And, yea, they basically say what you're saying. 6G6 is 36G turns of fuel on the missile.

I just find it curious that they had this insight in 1986, but, apparently, didn't use it in either BL or BR. The fact that they expanded the missiles to 12G was no doubt to make them more dangerous.

Just a serious change in the game, in behavior, operations, and cost, and then they "undid it" in TNE.

ss3 revised was done in the last 5 years.
Not back in the 80's.

 

[mike wightman]

I hereby petition the powers that be to take another look at this 'errata' and remove it - go back to the original version and intent of the rules which maintain compatibility between SS3, Mayday, BL, BR and TNE.