Which Edition? Converting CT/HG to MgT style ranges and range bands

[kilemall]

This is a repost of one I made to a player who wanted to run Drinax possibly under CT.


Well, lot of problems there, not the least of which CT never really merged LBB2, HG and/or Mayday that closely, and Mongoose adventures are going to assume Mongoose action/range/time scales. So, a challenge to make it easy to use MgT2E shipborne adventures in CT.



As some of you may have been following, I've been working up a CT/HG merge, which would play quite differently then either and reverse some of the assumptions/goals away from fleet demolition derby towards player drama.


So, I worked up a conversion using the CT Starter Edition Range Bands, a simplifying of the CT sensor system add-ons I had in mind but with the lock-on/intel mechanic (which I would gather is needed with what I've read between the lines about the nature of that adventure), a really nice EW war bit I'm happy with, and a simplified 'big guns' spinal and missile only Extreme Range.


In addition, I also reduced all scale items by x10, so range bands are 1000km, turns are 100s, and also threw in the EP allocation system and reversal of the critical hit system to disabled.


I had wanted to do a starter commentary version of the rules anyway, the full set is more complex and seriously alters the damage system, but this will do to open up discussion of some of the points I was going to throw out there anyway.

 

[kilemall]

Here is a quick and dirty conversion system to CT/HG for what I gather the MgT system plays like for the needs of the Drinax system. I'm not writing in dodge or any of that, but I'm assuming the adventure is written with MgT assumptions in play, including time for events to happen, and HG-like weapons.

CT combat is normally 1000s per turn, so it's more like ASW punctuated by deadly fire. I'm going to time/distance scale it down and use range bands. If you want a more classic true LBB2 version, up the time and scales by 10 and do the movement/vectoring and play by CT rules, with your own homegrown rules for armor and the like. I can help if you want to go in that direction.


Read CT Traveller Starter Edition for the Range Band system. Move missiles like ships, turret missiles 5G, bay missiles/torpedoes 7G and 60 turns of accel. Convert ships to HG stats. HG for hit/damage resolution. Detection as per CT /10 with die rolls, plug in stealth as needed.

The stuff in bold is where I added in mechanisms not in the original, but which I feel are needed to handle both common situations and ones I gather happen in Drinax.

Time scale- 100s turns
Range bands- 1000km
Detection- Civilian systems 15000km, military systems 60000km
Doggo detection- ships totally shut off and lying doggo are detected at 1/8 normal range, so 1250km for civilian sensors and 7500km for military sensors. Active sensors can be used as per lock-on to roll for initial detection at their normal ranges. Ships using active sensors to detect doggo ships are themselves detected at one higher range- civilian sensors will detect active sensors at 60000km and military sensors will detect active sensor use at 90000km.

Lock-on- Once a ship is detected, it is only a known object blip, course heading accel and HG general size class are known but no other information available. A target solution must be achieved to avoid a -6 DM to hit and calibrate other sensors to be able to gather more intelligence/tactical data.

Roll 8+ to lock on, DMs are Computer model compare +/-, sensor operator skill compare +/-, and +4 for either the locking or target ship use of active sensors.

Once the lock is achieved, the accurate ship size is known, intel items like weapons fit, power plant level, computer model, TL, etc. can be rolled as per the lock on roll. One intel item can be checked per roll, first roll that fails ends any information until the next 100s round.

Lock can be broken by the target ship on a roll of 8+, computer and sensor operator as lock on and -4 DM if either ship is using active sensors. A broken lock-on requires another successful lock-on roll to reestablish.

Tracking- Once detected, tracking out to 90000km
HG Ranges- Short Range 0-24999km, Long Range 25000-49999km, Extreme Range 50000-90000km.

Extreme range does not exist in HG rules. It is treated as Long Range except missiles can only engage if they still have accel fuel and only spinal weapons can hit targets, no bay or turret weapons can reach this far out.

Power Allocation- Ships use the HG EP system to prioritize system operations, especially when under duress in combat and/or damage has been taken. If damage is taken that lowers the ship's power output, the systems are maintained in order of precedence.

At the start of each 100s turn each ship captain determines what the priority of power allocation is. The typical 'everything powered' priority would be

Computer
Screens/Nuclear Dampers
Spinal Weapons
Defensive Weapons
Offensive Weapons
Maneuver/Agility

The HG-style breakoff priority would be

Computer
Maneuver/Agility
Screens/Nuclear Dampers
Defensive Weapons

A captain with Ship Tactics/Tactics (Naval) will have the crew trained to execute one specific priority list per skill level instantly, defined ahead of time. Otherwise, if it is an adhoc priority tactic it will take a 100s turn to explain and execute the new power priority list. The everything powered and breakoff priorities are known to all crews and do not count against the captain's options.

Critical Hits- Critical Hits are altered to system reduced to 50% value and disabled, not destroyed. Emergency repairs can reestablish the system to functionality, further repairs would be required to increase the functional value past 50% and further hits also apply to lower the system value.

 

[kilemall]

Hmm no bites.


Well, if you want to stay with the 1000s/10000km range band time/distance scale, just use the standard range band CT process and HG should work out okay for you.


Now then, I want to explore the interesting part of sizing it down to 100s/1000km, because I think it has some interesting commentary and applicability to the MgT fights, reaction times when you go from hour long decision cycles to less then two minutes, and some affects on the whole 'playing field' the original CT had set up with the 100D. Should this 1000km range band variant go to 10D, or possibly MgT?

First thing I noticed is that if you up the velocity per 100s per G, that you end up accelerating MUCH more quickly then you should.

1G at 1000s from 0 vee gets you 10000km velocity AND distance. Another 1G at 1000s gets you 20000km velocity and distance from the starting point of the previous turn, etc. You move one range band up in vee and distance.

Doing the same with 1G at 100s gets you going 10000km velocity at the end of 1000s, but you will have travelled much further if you do the per range band per turn move. So it takes using proportionate movement, which I worked out and will post on.


But some interesting things happen when velocity starts kicking in at 1/10 detection range.

A typical speed one might encounter is 10 vee for lack of a better term- velocity of 100000 km after 1G accel for 10 1000s turns. Usually well on the way outbound for a 100D jump.

That's 10 range bands every 100s with a 1000km scale.

So if a Free Trader runs across another ship, they won't detect them until 15000km. If the detected ship was at 0 vee and the Free Trader was at 10 vee, the FT will close to 5000km in one 100s turn, flash by and be at 5000km in another 100s, then take 200 more seconds to get to long range, 600 seconds to past long range, then 800 seconds to pass the 90000km loss of detection limit. That's using the adjusted CT detection scale.

If the ships were accelerating at each other the same rate, the window for action would be that much smaller.

Let's say they were both Type S or other military/scout sensor equipped, that's still 100s to get to long range, 2-3 turns of long range before you go to short range, 5 turns of short range, 2-3 turns of long range, then on away until out of range.




So a lot of things like getting your passengers and crew suited up for pulling atmo to vacuum probably couldn't happen that fast, launching ships or damage repair would take longer vs. firing action.

But you can flash by with enough acquired vee and 'get away' a bit easier, with a lot more 'darkness' and hiding in that space between the planet and the jump limit. Missiles fitted with sensors only, drones if you will, would be a much bigger thing to find ships ahead of your path or stay in detection range long enough to catch up.


Changes the feel up a bit, among other things pirates that can lie doggo then power up and run down slow traders are more likely to be a thing.

 

[kilemall]

Then looking at it from an MgT1E perspective and those sensor rules, if you were using that instead of the CT detection/HG range I'm proposing, 90000km is where ships disappear, 50-90000km is the twinkling IR limit alone.


You just apply the range modifiers as per the defined ranges for the range paradigm, but with the difference that you use the CT range band/vee rules and 100s turns/rounds and tracking missile moves instead of the narrative range method.


Velocity then becomes a thing to manage that can work for you or against you.

 

[AnotherDilbert]

So if a Free Trader runs across another ship, they won't detect them until 15000km.

Why such short detection range?

DETECTION
Ordinary or commercial starships can detect other ships out to a range of about one-half light-second; about 1,500 millimeters. Military and scout starships have detection ranges out to two light-seconds; 6,000 mm or 6 meters.
...
Tracking: Once a vessel has been detected, it can be tracked by anyone up to three light-seconds (about 9,000 mm, or 9 meters).

Even in MgT1 ships can normally detect, and shoot at, each other at Distant range (up to 150 000 km, same as CT), albeit with minimal detail.

Note that there is no contradiction between CT and MgT, it's just that most of CT range is called Distant range in MgT1 Core.



By making the turn shorter you will just make manoeuvring less important, as you slooowly change vectors, moving like stuck in molasses, making firepower the only important aspect of space combat, unless you tone down hitting and damage chances as well.

If you do tone down damage chances you will miss or do no damage most turns, possibly turning the system into something that is decided by a few lucky shots.

My point: If you do change the scale, you have to redesign the entire combat system...

 

[whartung]

Mayday has a blurb regarding High Guard.

5 hexes and less is Short range. 5-15 is Long range. 15+ is Out of range.

The scale is 300,000km per hex.

So up to 1.5Mkm is Short, up to 4.5Mkm is Long Range.

You can overlay that on top of your range bands.

 

[kilemall]

I am very aware of the Mayday blurb, but the speed/scale of that game is pretty much the exact opposite of anything I'd want to touch. From my perspective the useful bit of Mayday is simplified combat/fast results, just the thing to settle a big ACS engagement quickly.

 

[kilemall]

Why such short detection range?

The original Reddit thread was about using CT to run Pirates of Drinax. I felt that the POD campaign would require more HG-like equipment then LBB2 would offer and a world of people not doing vector movement per se, plus assuming MgT2E tasking and pacing so wanted to offer a CT experience that would more readily port whatever specifics are in POD.


If you like, run with CT detection and maneuver ranges. 10x scale- so civilian detection is 150000km, military is 600000km, short range is 0-250000km, long range is 250001-500000km, and extreme range with just spinals only is 500001-900000 km. That spinal only range is probably the more radical bit, would mean those big ol battlewagons would be jockeying to keep their big beams at range away from all those annoying little bay equipped cruisers.

Note that there is no contradiction between CT and MgT, it's just that most of CT range is called Distant range in MgT1 Core.

By making the turn shorter you will just make manoeuvring less important, as you slooowly change vectors, moving like stuck in molasses, making firepower the only important aspect of space combat, unless you tone down hitting and damage chances as well.

If you do tone down damage chances you will miss or do no damage most turns, possibly turning the system into something that is decided by a few lucky shots.

My point: If you do change the scale, you have to redesign the entire combat system...

Well, part of the point of bringing all this up is how all the 'simplistic' definitions in all these games, CT as well as MgT, have a specific purpose and breaking them SHOULD force people to reassess assumptions and consider desirable and undesirable game effects stemming from such changes- or how RAW could be improved.



Now then, as to effects- it depends on what you want. I don't like 1000s or 20 minute turns or even larger Mayday/Triplanetary scales. But I don't like MgT's movie action time scales either or the narrative space battle. 100s turns strike my sweet spot.

So this is definitely a princess and the pea preference re: scaling, I don't expect others to share my delicate sensibilities.


I'm mostly after drama, whether it's shooting or decisions or engineering repair, and sudden appearances of enemy ships appeals to that side of things.

That's single ships though- in a fleet engagement there would be scouts everywhere, of either the Type S/Type P/SDB variety, as noted swarms of missile sensor drones or fighters, so a lot of space combat would be finding the enemy and either forcing an engagement at the planet, getting the six at a controllable optimal range or making a high speed breakthrough/damage run at them.

I already had it in mind to redo the damage charts for a more simple/fast resolution system that allows for more close suicidal runs for underpowered ships or mighty blazing battleships standing off the enemy, looking to reduce most of the die rolls while ending up with more drama.

Example, the critical hits all go to disabled rather then destroyed. You get the mission kill but now there is engineering drama to repair the crippled ship in time to possibly turn the tide, rather then be a rapidly disposed of ship. The sort of thing to think of when your perspective is not to operate a ship design demolition derby test wargame but an adventure story.

This divide 10 scale gedanken experiment was outside of that effort and just prompted by the unusual Reddit request, but informed by a lot of thinking I'd already done on the CT/HG front, and I thought it would be interesting to lay out as a prompt to think about possible ATU fiddling others may consider. It was also interesting to see how it worked pretty well in the MgT ethos and how a real range band system port could work with pure MgT rules.

 

[kilemall]

Oh, and nobody EVER talks about all that space in the 50-90K + range outside of normal MgT combat yet you have the full 100D playground originally geared to the CT ranges.



So in a sense MgT ALREADY monkeyed with the playing field to get that drama timing, without dealing with the vast 'what is that IR dot' aspect of their enviornment, beyond IFF games.


Should MgT and/or this scale divided by 10 version have a 10D jump limit? Is that desirable? What are the ramifications of leaving 100D in and having all that mystery space outside the planet and before jump?

 

[Condottiere]

Game mechanism so that stealth coated spacecraft work, and I believe the hundred diameter limit was to encourage piracy.

 

[Fovean]

GURPS Space uses varying turn length for longer ranges, which I’ve adopted for my MgT game. So IMTU there are 6min, 3min, 1min and 30sec space combat turns.

It required adjusting the Thrust to Change numbers and the range band distances a tiny bit but gives a great sense of tense, sweaty sensor blips closing in to staccato bits of rapid-fire action as ships close then flash by one another. I use 10sec personal combat rounds so it folds neatly into boarding actions as well (6sec rounds always seemed too short to me, and 15sec rounds ala CT felt too long; this is a happy medium and my group likes it).

Next up we’re going to try accumulated acceleration for desperate runs to 100d limit.

 

[kilemall]

Game mechanism so that stealth coated spacecraft work, and I believe the hundred diameter limit was to encourage piracy.

The doggo function IMO was clearly meant to be 'sub in space', didn't really designate how shutdown the ship had to be or if it could detect and surprise ambush or know when it was clear to move off. I don't know that stealth was primarily in mind in 1977.


Obviously the planetary ambush part was more drama.


I think piracy was just part of it, looks more like a well-defined battlespace- planet on one side, 100D on the other. Coming in or going out, have to slow down and traverse at an interceptable pace thus creating an artificial space to fight in.


The more we keep the functionality of such rules in mind the more we can shape them to the ends we want in our games for our versions.

 

[kilemall]

[FONT=arial,helvetica]GURPS Space uses varying turn length for longer ranges, which I’ve adopted for my MgT game. So IMTU there are 6min, 3min, 1min and 30sec space combat turns.

It required adjusting the Thrust to Change numbers and the range band distances a tiny bit but gives a great sense of tense, sweaty sensor blips closing in to staccato bits of rapid-fire action as ships close then flash by one another. I use 10sec personal combat rounds so it folds neatly into boarding actions as well (6sec rounds always seemed too short to me, and 15sec rounds ala CT felt too long; this is a happy medium and my group likes it).

[/FONT][FONT=arial,helvetica] Next up we’re going to try accumulated acceleration for desperate runs to 100d limit.[/FONT]

Ok good, the more you know what you want the more you can make it your own. That's the point of this thread.



For the full CT/HG conversion I've been considering 1:1 1000s, 1:10 100s, and 1:100 10s shots. The short range in those cases would be 250000km shots every 1000s, 25000km shots every 100s, and 2500km shots every 10s. Power is the same, just less stored up capacitor power for shots, and closing with the enemy is a 'clenching terror' sort of event.


OR, each closer shot still happens at 1000s scale, but is progressively more powerful, which eventually burns through HG armor. Similar kinetic effects with the missiles, but in reverse, the missile needs time to accelerate to lethal speeds.



Among other things, it clarifies why ANY boarding should be on small craft rather then risk the 'mothership' on close ruinous battle.

 

[Grav_Moped]

...
I think piracy was just part of it, looks more like a well-defined battlespace- planet on one side, 100D on the other. Coming in or going out, have to slow down and traverse at an interceptable pace thus creating an artificial space to fight in.


The more we keep the functionality of such rules in mind the more we can shape them to the ends we want in our games for our versions.

The original conception of transit to and from the 100D limit required (or at least expected and didn't provide for alternatives) zero velocity at the Jump Limit both on departure and arrival. T5 assumes "running" jumps as the default; I haven't checked other rulesets.

(I'm pretty sure I'm not disagreeing with you here.)

 

[kilemall]

The original conception of transit to and from the 100D limit required (or at least expected and didn't provide for alternatives) zero velocity at the Jump Limit both on departure and arrival. T5 assumes "running" jumps as the default; I haven't checked other rulesets.

(I'm pretty sure I'm not disagreeing with you here.)

I don't recall ANY requirement to stop with CT, I always assumed a running jump AND retained vee on reentry.


I've no objection to preferences or variations later versions imposed, just that I don't recall that being a 'requirement'.

 

[Silverhawk]

Obviously the planetary ambush part was more drama.


I think piracy was just part of it, looks more like a well-defined battlespace- planet on one side, 100D on the other. Coming in or going out, have to slow down and traverse at an interceptable pace thus creating an artificial space to fight in.

I agree, if there wasn't a limit to keep a ship from immediately turning around and jumping (either out system or micro jump within the same system) there would only be combat if the participants were a point blank range to begin with.

The more we keep the functionality of such rules in mind the more we can shape them to the ends we want in our games for our versions.

Absolutely agree with you on this.

 

[Silverhawk]

I don't recall ANY requirement to stop with CT, I always assumed a running jump AND retained vee on reentry.


I've no objection to preferences or variations later versions imposed, just that I don't recall that being a 'requirement'.

Page 43 of my copy of High Guard (1980 Edition, I checked to be clear) mentions the possibility of a fleet of Black Globe ships jumping in on a predetermined course with a set velocity and the globes up with no flicker in order to sail in drop at a set time and then blast away at the surprised enemy.

That would support the idea of a running jump and retained velocity.

 

[whartung]

JTAS #24 mentions both retained vectors and differential vectors after jump.

Anyone "stopped" in system A will most probably not be when they arrive simply due to the different vectors the surrounding systems are moving.

"Stopped" relative to what?

I've also see a reference somewhere (and I can't directly recall) about ships being able to change their "normal" space vector while in Jump.

So, in theory, you can have a ship add 1 week of acceleration while in jumpspace. (Cue the "C rocks and starships" thread.)

But I don't remember where I saw that.

 

[mike wightman]

It's in T5

 

[AnotherDilbert]

"Stopped" relative to what?

Traveller doesn't consider relative movement of star systems. Even the star map is simplified to two dimensions...

No reason you can't do it, of course.

I've also see a reference somewhere (and I can't directly recall) about ships being able to change their "normal" space vector while in Jump.

So, in theory, you can have a ship add 1 week of acceleration while in jumpspace. (Cue the "C rocks and starships" thread.)

Yes, it's in T5, but note that gravitic drives does not work in jump space, only reaction drives work.

If you have rocket fuel for a week, go right ahead...

Movement Vector Can Be Changed
A ship can change its speed and direction while in jump space. Vector change requires non-gravity-based drives or devices; gravity-based drives (due to their need to interact with gravity sources) are generally ineffective.