Kosmic Chapter 7 Space Combat

Here is the PDF of Chapter 7 Space Combat from Kosmic, found on DTRPG.


It is a mix of Mongoose Traveller 1e from the SRD, and Cepheus Engine. It has new things such as hex combat, Newtonian movement, GLOC, turrets have RoF instead of weapon count, some different weapons such as rail guns, larger bays, and some other variations.

The scale needs work. This is due to MgT range definitions.

If 1 hex is 5000km then how do you know if a ship is at close, short or medium range since they are all in the same hex?

The Mongoose thrust to change range band is also Newtonilly suspect, especially since you say momentum is conserved. Why not just use a better Newtonian combat system?

Here is a easy way to do it that only requires a circle of hexes with a central hex on your ship display.

Number each internal face of the central arrow 1 to 6. Draw a big arrow in the middle pointing to which way is forward from the frame of reference of the ship - usually direction 1.

Each turn you can spend thrust to gain velocity in any of the directions at the cost of 1 thrust per V. So let's say on turn 1 I order full ahead and move 3 in direction 1. I write a 3 in the hex on the ship display on the 1 face. Every turn until I do something else I have a V of 3 in direction 1.

If I wish to turn then I can apply thrust in a different direction, let's say a tight turn so I put 3 thrust to go in direction 3. I move the ship counter 3 in direction 1 and then 3 in direction 3. Every turn from now on I have to do this until I apply thrust in a different direction.

Note - the ships nose is assumed to be pointing in the direction of any thrust applied that turn, but if the ship is coasting it may point its nose in any direction (in case you want facing for weapon fire)
Note - if you want real Newtonian movement then you only move the ship counter half the distance of the acceleration in the turn it is applied.

This is actually pretty easy if you stick with 5,000km hexes since 1000s of acceleration at 1g gives a velocity of 10kps or 10,000km in 1000 seconds

So a V of 1 actually moves you 2 hexes per turn in that direction.

At the end of each turn subtract opposite face velocity to get the resultant

Try to do it without any numbering hexes, or calculations, only moving ships. Your way is too complex, this has abstractions, simplified for game purposes. This has to be runnable without any knowledge of physics, I tried to keep some realistic elements. As well as some things were kept as to not really being any different in use. We have played it at the table for around 10 years, I use a hex map and little spaceships. Part of the simplification of movement is that turning scrubs forward movement, in truth, I'd have to find an equation of changing direction, how much excess energy it would take. It is all doable, though as I mentioned, this has to appeal to people without any interest in the real physics. The majority of the chapter is about character actions, movement is only a small part of it.

mike wightman said:

If 1 hex is 5000km then how do you know if a ship is at close, short or medium range since they are all in the same hex?

Click to expand...

On page one:

Close: 0 – 10 km same hex
Short: 10 – 1250 km 1 hex
Medium: 1250 – 10,000 km 1 to 2 hexes
Long: 10,000 – 25,000 km 3 to 5 hexes
Very Long: 25,000 – 50,000 km 6 to 10 hexes
Distant: 50,000 km+ over 10 hexes

All this depends on your weapon systems.

For pretty much everything outside of guided missiles, 1 hex (1250km) is too far. Especially with Traveller power (1G+) drives.

Traveller combat works because it lets lasers and energy weapons work at astonishing distances.

If you're using anything kinetic, 1250 is just simply out of range.

Dragoner said:

Try to do it without any numbering hexes, or calculations, only moving ships. Your way is too complex, this has abstractions, simplified for game purposes.

Click to expand...

My method is simplicity itself, all you need is the velocity in the six faces and you move those hexes every turn, you only change the numbers if you accelerate, and by doing a bit of simple maths - subtracion. The hexes don't have to be numbered, all the info is on the ship data card (although is you have a hex map printed to transparent plastic you could make a base for the ship token) and all the info is on the board. You get a vector movement system without multiple counters on the board or having to draw vector arrows. perhaps I am not explaining it simply enough but it really does work.

Dragoner said:

This has to be runnable without any knowledge of physics,

Click to expand...

All you need with my method is to write a number in a hex and move that number in that direction every turn, at the end of every turn rationalise the numbers - if subtracting opposite numbers is too difficult I would imagine the rest of the task resolution system is.

Dragoner said:

I tried to keep some realistic elements. As well as some things were kept as to not really being any different in use. We have played it at the table for around 10 years, I use a hex map and little spaceships. Part of the simplification of movement is that turning scrubs forward movement, in truth, I'd have to find an equation of changing direction, how much excess energy it would take. It is all doable, though as I mentioned, this has to appeal to people without any interest in the real physics. The majority of the chapter is about character actions, movement is only a small part of it.

Click to expand...

So not Newtonian at all.

Dragoner said:

On page one:

Close: 0 – 10 km same hex
Short: 10 – 1250 km 1 hex
Medium: 1250 – 10,000 km 1 to 2 hexes
Long: 10,000 – 25,000 km 3 to 5 hexes
Very Long: 25,000 – 50,000 km 6 to 10 hexes
Distant: 50,000 km+ over 10 hexes

Click to expand...

A hex is 5,000km, so a ship in the same hex is at close range, short range and inside medium range. Two ships in the same hex could be anywhere from in contact to being 4,999km apart.
A ship in an adjacent hex is 5000km to 9,999km so medium range. Like I said, you have got to get the scale sorted out..

mike wightman said:

You get a vector movement system without multiple counters on the board or having to draw vector arrows.

Click to expand...

Don't you find that the lack of "future" counters make it difficult for other players to know your vector?

This is the core of movement:

Thrust number is the same
as it maneuver drive number, so if a
ship is M6 it has 6 thrust. One thrust
is one hex worth of movement, or it
can turn in a hex one side per thrust
number.

That is all they have to know. It is kept simple by design, without writing things down, and doing calculations. I did try a more complex system, and then edited out, the book went from 468 pages down to 354. I am not against a more complex system, like "Advanced Kosmic." It is not complex as is, everything is there. Without playtesting the suggestions, it is unknown how or even if they work.

Ranges are dynamic in their time frame, not static. Easy enough to look at the table.

whartung said:

Don't you find that the lack of "future" counters make it difficult for other players to know your vector?

Click to expand...

They can see your movement on the map.

Which brings up another option.

Both sides can spend this turns thrust in secret and the opponent doesn't know how it has been spent until the counters are moved.

You don't even need a dedicated template - just a way to record the velocity in each of the six hex directions. 5 0 0 0 0 0 is a velocity of 5 straight ahead, 5 2 0 0 0 0 is a velocity of 5 straight ahead and 2 at 60 degrees, 5 2 0 0 0 2 is 5 straight ahead 2 at 60 degrees and 2 at 300 degrees... it really is much simpler with visual hexes. I can demonstrate it in less than a minute and people are confident after three to four turns.

Playabilty has to be important, otherwise try it with 10 ships, 100 times; it looks like too much to figure out.

Dragoner said:

This is the core of movement:

Thrust number is the same
as it maneuver drive number, so if a
ship is M6 it has 6 thrust. One thrust
is one hex worth of movement, or it
can turn in a hex one side per thrust
number.

That is all they have to know. It is kept simple by design, without writing things down, and doing calculations. I did try a more complex system, and then edited out, the book went from 468 pages down to 354. I am not against a more complex system, like "Advanced Kosmic." It is not complex as is, everything is there. Without playtesting the suggestions, it is unknown how or even if they work.

Ranges are dynamic in their time frame, not static. Easy enough to look at the table.

Click to expand...

So thrust 1 is 0.5g? And no momentum? A touch of the abstract but it does what you want it to

Mine takes half a page, I just wish I had the graphics skills to illustrate what I mean, or could explain it face to face and show you, it really is simple.

Dragoner said:

Playabilty has to be important, otherwise try it with 10 ships, 100 times; it looks like too much to figure out.

Click to expand...

It isn't, you can use a piece of paper to record as many ships and missiles as a typical squadron vs squadron engagement. We've done a 20 vs 34 no problem. For learning purposes it is best to do ship vs ship , then a few ships vs a few ships. Once you get the hang of it it is pretty simple and easy, it just sounds complicated. For fleet vs fleet then I lump fighters into squadron counters.

Thrust is nominal 1g; though dynamic, so anywhere from 0-1g.

I had to stand there and watch kids figure it out without me explaining it, so it was pared down to rules light. If it at least gets them a slight bit interested in classical mechanics, I am satisfied.

mike wightman said:

It isn't, you can use a piece of paper to record as many ships and missiles as a typical squadron vs squadron engagement. We've done a 20 vs 34 no problem. For learning purposes it is best to do ship vs ship , then a few ships vs a few ships. Once you get the hang of it it is pretty simple and easy, it just sounds complicated. For fleet vs fleet then I lump fighters into squadron counters.

Click to expand...

We do small ship, so each fighter and missile barrage is generally tracked. As a designer I had to make choices, I chose ease of use over making a more accurate physics engine, partially due to keeping it within the realm of Traveller rules.

Dragoner said:

Thrust is nominal 1g; though dynamic, so anywhere from 0-1g.

I had to stand there and watch kids figure it out without me explaining it, so it was pared down to rules light. If it at least gets them a slight bit interested in classical mechanics, I am satisfied.

Click to expand...

1g for 1000s is a velocity of 10,000km or two hexes per turn after the turn the acceleration took place.

It was the Newtonian physics of LBB:2 combat that got me to study harder in maths and physics.

mike wightman said:

1g for 1000s is a velocity of 10,000km or two hexes per turn after the turn the acceleration took place.

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1g acceleration for 1,000 seconds is 4,903 km; at 9,810 m/s it is 14, 713 km.

That's a distance travelled or displacement calculator, not a velocity calculator.

At the end of the 1000s of acceleration at 1g - which Traveller sets at 10ms^-2 - your velocity is 10km/s or 10,000 km per 1000 seconds.

If you start from 0 and accelerate at 10ms^-2 for 1000s then you can calculate displacement using 1/2 at² since initial velocity is 0, if already moving than you need to add a ut (u is initial velocity) for ut+1/2 at², so you displace 5000km. But the next turn your velocity is now 10,000km per 1000 seconds because v=u+at so you will move 2 hexes even if you don't accelerate.

Apart from an optional rule in CT 77 Traveller has always done displacement wrong. You only move half the distance your velocity change due to acceleration on the turn you accelerate.

For accuracy use 5000km hexes but a velocity of "1" only move 1 hex the turn the acceleration is applied and then 2 hexes for subsequent turns.

Very few tabletop games get this right.

It calculates velocity also, your velocity is ever increasing. We tried it realistically and after a few turns it slowed to a grind, this was also the problem with LBB2 and Mayday.

Newtonian movement or non-Newtonian movement, if the latter then it isn't Traveller to me. You may as well switch to stutterwarp or other non-Newtonian system, they have the advantage that they are much easier.

The level of complexity you want is simply not popular, I am not free of that consideration as a designer, I have to make it playable. Every version of Traveller past LBB 2 (which is pseudo-newtonian) is non-newtonian. It is what it is.

TTB, Starter Traveller, TNE, T4, T5 are all Newtonian.

The only versions that aren't are MegaTraveller and Mongoose Traveller. Even some versions of CE have corrected Mongose Traveller's mistakes.

Mongoose itself now offers Newtonian vector movement in the Traveller Companion.