Starship Combat

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Ratchet2012 Ratchet2012's picture
Starship Combat

This is just a quick thread Im doing... In the book it says that there's no ship-to-ship combat... and Im would love to RP at the helm and do some SHip combat but... well no rules on, is there anyone who has any rules for this? (Like: new ships, shuttles, systems, and weapons?)

Arenamontanus Arenamontanus's picture
Re: Starship Combat

See the big
http://www.eclipsephase.com/space-naval-combat-segway-antimatter-thread
thread. Since that one I have been working on and off on a paper analysing this stuff in *excruciating* detail.

I think real space combat is not going to be very fun in itself: In deep space you spend a few days making minor manoeuvres, manufacturing and releasing weapons/sensors, and then you get to spend a few minutes in mortal danger as software does the fighting. In orbit it is the same thing, except that everything is by surprise and even deadlier, plus there are going to be innocent bystanders.

However, I think there is plenty to be said about the cool stuff *around* it. Sensor arrays monitoring where most ships in the solar system are (no, it is nearly impossible to hide), tricky stealth strategies, the "cloud combat" between offensive and defensive assets, military uses of QE, the perennial debate between laser, railgun and missile fanciers, the fearsome defence installations near Titan and the economics of piracy. That is where adventures can be run, the real space battle is just near-random player kill.

Extropian

Ratchet2012 Ratchet2012's picture
Re: Starship Combat

Arenamontanus wrote:
See the big
http://www.eclipsephase.com/space-naval-combat-segway-antimatter-thread
thread. Since that one I have been working on and off on a paper analysing this stuff in *excruciating* detail.

I think real space combat is not going to be very fun in itself: In deep space you spend a few days making minor manoeuvres, manufacturing and releasing weapons/sensors, and then you get to spend a few minutes in mortal danger as software does the fighting. In orbit it is the same thing, except that everything is by surprise and even deadlier, plus there are going to be innocent bystanders.

However, I think there is plenty to be said about the cool stuff *around* it. Sensor arrays monitoring where most ships in the solar system are (no, it is nearly impossible to hide), tricky stealth strategies, the "cloud combat" between offensive and defensive assets, military uses of QE, the perennial debate between laser, railgun and missile fanciers, the fearsome defence installations near Titan and the economics of piracy. That is where adventures can be run, the real space battle is just near-random player kill.

... well this sucks, I love huge space battles... -__- There has to be a way to make ship combat more fun for us ship junkies ... please don't tell me i wasted my money on this game, when no space combat is in it. cuz last time I watched a Comic Con vid on Youtube they said the game is universal in many ways... (I'm not tring to be an ass... just tring to get mine and other starship lovers voices out.)

InsidiousAlgorythm InsidiousAlgorythm's picture
Re: Starship Combat

*rant* You want space ship battles you should have went with a video game or something, you may have wasted your money, so give your books to an actual role player. Maybe you should have read the book more before you bought it. */rant*

Yeah, I'm being an ass here, my apologies. I just hate it when I hear people whining over the little details like this. Like Arena mentioned, Space combat in a "hard" sci fi universe is impossibly boring with a few intense moments where you may or may not be vaporized in a moment of bad luck. Even the small details like "catching up" to another ship in a realistic manner would be difficult at best. EP, much like Burning Empires uses ships as plot devices and setting more than anything. You want to make it more exciting, and toss out the Hard SF stuff, then improvise and have the players make a few piloting rolls, and a few gunnery rolls too and go from there. Easy.

Arenamontanus Arenamontanus's picture
Re: Starship Combat

Ratchet2012 wrote:
... well this sucks, I love huge space battles... -__- There has to be a way to make ship combat more fun for us ship junkies ...

Have you read Scott Westerfeldt's "The Killing of Worlds"? Most of that book is taken up by a space battle, and it is fairly exciting yet not too far from how I envision EP style space battles. Spaceships moving along fairly rigid trajectories, large clouds of sensors and weapons, devastating interactions once they get into range. I think it can be done.

The one thing that has to go is the hotshot fighter pilot. Transhuman reaction speeds are simply not up to what is needed here, and most of the in-fight piloting is likely done by AI or even faster cut-down software (maybe some of this is based on forks of great pilots... Luke Skywalker is living the high life in Elysium thanks to the royalties from selling his fork to Trillicom Arms, now used as control mechanism in countless missiles).

If I were to actually run a space battle it would likely be some form of mass combat system (even for two ships). The commanders on respective sides make strategic decisions, deciding what kinds of assets to launch and the overall strategy (some space strategy rolls here). Then the asset clouds begin passing through each other, sensing and attacking like crazy. This can likely be treated as attrition warfare with some bonus from the strategy. Whether key targets like the ship are hit can be determined by rolls based on how much damage the opposing cloud does (again with some bonuses for smart strategy). Abstracted enough I think it could be turned into a possible game system, but it would leave most of the drama of sensor arrays trying to detect incoming missiles against the flares of firing weapons, PCs strapped into antiacceleration gel pods, fighter crafts dodging through laser fields while depositing stealth missiles on trajectories that will allow them to launch deadly Casaba-howitzer nuclear detonations at the enemy ship...

Extropian

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

It has no default space combat. However, the system is simple enough to cobble something together if you want. Maybe just create ships as characters and scale up the current combat rules?

If you are looking for a more tactical model, no, EP is pretty far from what you want (but those systems are also usually extremely ungainly and math-heavy). Unless you love math as much as I do, I honestly would recommend finding a computer simulation. You really can't get around it otherwise.

Arenamontanus Arenamontanus's picture
Re: Starship Combat

OK, I give in: here is the current state of my writeup on the physics of EP space combat.

http://www.aleph.se/EclipsePhase/EP%20naval%20strategy.pdf

Please note that it is a work in progress with some ugly formatting issues and several important sections in need of finishing. But I think you might find it interesting.

I would love to hear more comments, especially for getting the sensor analysis better grounded. I am honestly suspicious of my numbers, and would love if somebody who knows photometry could help me here.

Extropian

Arenamontanus Arenamontanus's picture
Re: Starship Combat

I hope I didn't scare you with that post. I would love to develop this field more.

One thing that I think is worth thinking about is the ships between the Fighter and Destroyer. The Destroyer is a monster (the *engine* is a particle beam weapon that can dig through miles of rock!), but it is also heavy, expensive and vulnerable - just what I would expect the Jovian Junta to build.

If my analysis is right, the real advantage will go to ships that are more like carriers of lots of little assets. They sweep in, deposit clouds of weapon buses, sensors, decoys and fighters, then keep out of the way from the real battle. I see them as "high bandwidth frigates" or agile carriers. They might be very lightly armoured, hoping the damage just goes straight through than spread.

Another big problem is hiding course adjustments - they are visible across the solar system, and there are too many eyes. I wonder if there is an advantage in "stealth drives" that push by expelling really cool and heavy propellant (e.g. using a railgun)? I doubt they can be made to work, but that would allow surprise appearances on someone's doorstep.

Extropian

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

I'd remove 'noindent' from the first line under Abstract. Also, there's some formatting issues on the bottom of page 4. Weird sentence format on p. 8 ("it only got about ...") and Joule should be plural at the end of that same column. Your equation on p. 9 crashes into the neighboring column. "Jupiter" should be capitalized on p.10 Graphs on p. 13 are too small to be legible. p.24, last paragraph, a space missing in 'wardheador'.

Reading through the cooling section was pretty informative. I'm imagining ships have massive, unfolding wings as radiators. Not restricted by drag (but still sensitive to impacts from on-coming debris), they might be swept back like concord wings, stretched like a grey goose, or shaped like butterfly wings. I'm sure some shapes are more efficient for specific purposes, but aside from freighters (which I assume to be flat rectangles) and warships (which I assume to have multiple swept fins to reduce damage and provide redundant systems), anything goes, yes? Generally they'd be highly reflective, or grey-white?

What does a water droplet radiator look like? I searched, but didn't see anything.

I imagine that, in preparation for battle, warships will intentionally cool the ship to the lowest tolerable temperature. This will permit them to operate longer without extended radiators. Civilian ships will meddle less with temperature; added radiators mean added mass, slower acceleration, additional needed fuel and so on. Circulators tend to be hot with so much activity. Freighters tend to be cold when coasting, and hot when performing maneuvers.

What you've written up so far is excellent. Very good reading. People who are intimidated by the math can still skim through and get your points easily. I think it would be fairly easy to write up simple, d100 mechanics for sensors, weapons, damage and armor. However, maneuvering in a 3D+T environment would be difficult to portray easily. If anyone has any brilliant ideas, we could probably write up our own space combat system which takes (not counting equipment lists) 30 pages or less.

Maneuvering rules must be:
Mathematically simple (no square roots or complex formulas) in the spirit of the pre-existing EP mechanics
Functional with minimal or no graphics, maps or models
Related enough to the scene to be intuitive (so no crazy SR3 maneuver scores)
Offer quick mathematical resolution

I'm imagining two current possibilities;
1) A series of strategy skill rolls (or captaining + navigation or whatnot), modified by intelligence and ship capabilities. These can give specific circumstances, or general combat bonuses. Otherwise combat works basically like character vs. character combat, except with naval scale damage codes and armor.

2) Resource allocation. Imagine your 'fuel tank' is a stack of twenty pennies. You can take some of those pennies and spend them (via your delta-v) to reposition yourself, changing speeds (altering the length of the engagement), giving some bonuses, or shift them over to firing weapons, or to repairing damage and so on. Each ship has their own 'fuel tank'. If you run out of pennies, your ship is dead in the water. Combat works like normal (as above), so if you run out of health, your ship explodes. Your ship defines the exchange rate between pennies and different actions. Skills of the crew members determine your success at those actions (so you can spend 2 pennies on maneuvering. Your helmsman rolls his Space Combat skill to determine what, if any advantage you achieve.)

Foucault Foucault's picture
Re: Starship Combat

Wow, that was a lot of work! It's really good stuff. I've got some comments and suggestions, mostly formatting or grammar.

First, it looks to me that you are using LaTeX, yes? What document class are you using? It looks like Book with two-column mode on. I'd suggest either switching to something with wider margins like Article or using only one column.

-Page 7. You say "this table" but don't have a reference, what table is it referring to?
-P.7. Your leading quotes are in the wrong direction. TeX recognizes ' as trailing quotes and ` as leading quotes.
-P.9. I thought there was a way to make a section take up the full width of a two column article, but I can't find it right now. This problem would also be solved by switching to one column.
-P.9. You have the word "sublight" where I think you mean "sunlight".
-P.10. I think Albedo is the first term you use that isn't pretty obvious, perhaps define it?
-Figures 1&2. These are unclear, but I figure you know that. You could adjust the width of the figures so you get more space for them.
-Neutrino positional detection. I'm pretty sure they can do position, Kameokande was able to pin point the supernova 1987b when it showed up. When the neutrios interact in the water tank detectors like Kameokande they produce a ring of Cherinkov Radiation at a 45 degree angle to the path of the neutrino, so they can use that to point the neutrino. I'll have to ask my friend who does neutrino astrophysics.
-P.19. I think you meant Evap where you have Eeap.
-P.22. Your section on "multi-barrel" railguns mentions sleeves out of nowhere, what are they and why are they important?

Finally I'd like to offer two more ideas for munitions. I know that GURPS Transhuman space really likes X-Ray Lasers that are pumped by nuclear bombs, I've never been all that clear on how they work but I think they are a real thing. Second is a subset of the particle beam weapons. With a laser intensity on the order of 10^20 W/m^2 incident on a gold foil you can make a beam of electrons with >1MeV energy. With some tricky target shape you can get a pretty decent divergence angle, so this might be useful for beam weapons. Though I don't know quite how it scales. That stuff is cutting edge physics for Fast Ignition Fusion, and infact my current research field. So who know's if it's viable.

I hope you'll take my comments constructively. I really like your work and look forward to seeing it as it progresses.

P.S. While I don't have personal experience with Fantasy Fligth's Rogue Trader I'm informed that it has a good system for allocating work to all players in Starship Combat, so that might be something to look into. Warhammer though does laugh in the face of the laws of physics.

R-Rep: 2

InsidiousAlgorythm InsidiousAlgorythm's picture
Re: Starship Combat

Arenamontanus wrote:
I hope I didn't scare you with that post. I would love to develop this field more.

Good god man! I have a headache now LOL too much math. Seriously I understand (most of) it, but is that all really necessary for our purposes? There is a difference between Hard SF and a physics dissertation. Sorry mate, I don't mean to be too critical, you do great writing but for game purposes I don't think this will work out (for me) at all.

I'm a very patient reader, but if my brain gets bored and doesn't want to keep up with all the formula involved, I don't think it will be any fun. Feels too much like a GDW game to me.

Just sayin'

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

Keep in mind, Aremanteraraous probably has more letters behind his name than you find above a kindergarten chalk board. I believe he works in neurophysicsnanoastrobionomy.

More seriously, this is a HUGE help as a writer. Sure, you don't want all of these formulas on the game table, but you want the rules you operate to be based off of them (or at least aware of them). What he's done is given us guidelines so we can create consistent ships that operate in a consistent manner in a consistent universe. Sure, it may not be the table you play your game on, but it is the concrete foundation that holds up the house for your table to fit inside.

Arenamontanus Arenamontanus's picture
Re: Starship Combat

Thanks for the comments! Some responses in no particular order.

Formatting: yeah, it looks awful right now. I will fix it, together with spelling and grammar. Looking back, choosing the two column style in LaTeX wasn’t the smartest choice.

Cooling: yes, those cooling radiators can be real fun (great place to have a fight on, or for descriptions of graceful ships). The surface should ideally be high-emissivity, which means as non-reflecting as possible – dull or black is good. It could be colored if you want.

Droplet radiators make use of liquid metal droplets rather than water. Water would work, but much more inefficiently. It would look like a transparent dull red sheet. There are some pictures on http://www.projectrho.com/rocket/basicdesign.php#Heat_Radiators and http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19870010920_1987010920.pdf

Neutrino positional detection: good point. I think you might be right. This is likely bad news for antimatter powered missiles since they would show up very clearly as directional neutrinos. Might still be hard to tell where a neutrino source is unless you have three tanks to triangulate with.

"Multi-barrel" railgun sleeves: this is from a paper I found analyzing the performance of various railgun designs. The sleeves are a part of the construction. The notes are mainly relevant since they give a sense of scale of a railgun.

Nuke or AM powered X-ray lasers: an old favorite, likely quite doable in EP. Whether they are cost effective I don’t know. This is a good way of getting a sharp high impact laser pulse doing shockwave damage, but EP likely has optics good enough to do it with longer wavelengths too. It could be a matter of design choice: detonation lasers are popular among groups that have plenty of nukes or AM to burn.

Love the electron beam, but I wonder how good divergence angle you can get over long space distances – ships will likely be 1000s of km apart. Might be good for point defenses though: you want to ionize things to the degree that they spread out, and incidentally the beam will kill all nano in a projectile.

Making a playable system: yes, I think one could do something nice with markers representing a fuel stack and maybe another for nanofabber/armory resources. Launched or shipboard ‘guns’ are able to remove enemy markers with an efficiency dependent on how much sensors there are.

Extropian

Arenamontanus Arenamontanus's picture
Re: Starship Combat

Here is something I literally dreamed up tonight, a space battle system for EP as a card game. Still not quite finished (we need to figure out the cost of the cards, I am definitely unsure about how to balance the ships) and obviously not playtested. But I think it has promise - it abstracts some of the logic I see in space warfare. It might of course annoy us who like to keep a 'pure' d100 dynamics but I think the cards make sense to keep track of all the little devices.

Ship battle

Each player has a hand of cards corresponding to their assets: weapons, sensors, decoys and one or more spaceships. Each side has a number of points to spend on building their hands.

There is a general discard pile and a destroyed pile that is emptied into it after each round.

A fixed number of turns, determined by the relative velocity, are played.

The player with the longest range or best strategy begins.

Turn order:

1. On their turn, each player places a number of sensor and weapons cards face up in front of them. It can be any number of the cards on the hand.

2. A number of sensor cards equal to the number of cards discarded to the destroy pile in the previous round are tapped (turned 90 degrees); they cannot help targeting.

3. Each working sensor allows hitting one different target. If there are fewer sensors than weapons then some of the weapons must attack the same target.

4. Each attacking weapon must either attack a card lying face up on the table, or a randomly chosen card in the hand of the player. Most cards are immediately put into the destroyed pile; the exception is the spaceships (see below). A weapon that has been used this turn is tapped.

5. After the attacks have been handled the player returns the sensor cards to the hand. Weapon cards will remain face up on the table (except for one-use weapons) and are returned to untapped when it is the player’s turn again.

Winning: The winner is the side that retains spaceships while the other lacks them. If both or neither have ships, then the side with the most card points wins.

Ship defense: If a ship is attacked in step 5, then it can defend itself. For each railgun and missile attack (but not laser attacks) it can use one of the point defences on its card as well as untapped weapons cards on the table. Weapon cards from the hand can also be placed on the table and used immediately. For each defending weapon roll one dice; on a 1 against a railgun projectile and 1 and 2 against a missile the incoming attack is stopped. If it gets through the ship is either destroyed or damaged (as per the card). All used weapons except for ship point defences are tapped. The ship card is now face up on the table and can be used as a weapon.

Ship cards

Fighter
Point defense: 3
Weapon: 2 railguns
Destroyed by one hit.

Destroyer
Point defense: 6
Weapon: 2 railguns, 2 lasers
After each hit, put a marker on the ship. Destroyed after three hits.

Weapons cards
Laser array
Railgun
One-shot laser (put in destroyed pile after use)
Missile bus (When placed on table, it turns into N missile cards. Bus remains and can be turned into one missile before being immediately discarded)
Missile (put in destroyed pile after use) (types: Kinetic, Nuclear, AM, Nano)
Blinder (when activated, acts as N extra destroyed objects for blinding enemy sensors. Put in destroyed pile after use)

Sensor cards
Sensor device
Active sensor (when used it cannot be returned to the hand and must remain on table)

Decoy cards
Decoy
Chaff (if chaff is hit, it is not discarded)

Action cards
(these cards can be bought like other assets but are kept in a separate pile)
Dodge (Play when ship is being attacked. Acts as 3 point defenses, even against laser. Discard after use)
Armor/repair (Play after a ship is hit. Reduce the number of damage tokens placed on ship by one. Discard after use)
Triangulation (Play before targeting. Tap three sensors. Reveal a random card from the opponent’s hand and put it face up on the table. Discard this card after use.)
Stealth (Play at any time. Return a face up card to the hand)
Dead angle (Play when one of your cards is rageted. A particular weapon cannot target that target and must select another. Discard after use)

Extropian

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

That sounds like a good way of tracking things, although it takes out any chance of random misses, evasive maneuvers and so on (or of the skill of the crew on board). It also seems to ignore something like a critical, penetrating hit which immediately hits a critical system.

InsidiousAlgorythm InsidiousAlgorythm's picture
Re: Starship Combat

nezumi.hebereke wrote:
Keep in mind, Aremanteraraous probably has more letters behind his name than you find above a kindergarten chalk board. I believe he works in neurophysicsnanoastrobionomy.

More seriously, this is a HUGE help as a writer. Sure, you don't want all of these formulas on the game table, but you want the rules you operate to be based off of them (or at least aware of them). What he's done is given us guidelines so we can create consistent ships that operate in a consistent manner in a consistent universe. Sure, it may not be the table you play your game on, but it is the concrete foundation that holds up the house for your table to fit inside.

neurophysicsnanoastrobionomy! hahaha. You forgot Xeno.

Seriously, I wasn't saying what arena wrote was awful or anything, quite the opposite, I was only trying to point out how difficult it would be for "the average reader" (Whatever that means) to pick up and use effectively. I agree, reading that gave me a slew of ideas, I especially like that he included using the drive as a weapon (Very "Prefect").

Arenamontanus Arenamontanus's picture
Re: Starship Combat

InsidiousAlgorythm wrote:
neurophysicsnanoastrobionomy! hahaha. You forgot Xeno.

Yup. I will actually work on a SETI-related project this weekend. :-)

Quote:

Seriously, I wasn't saying what arena wrote was awful or anything, quite the opposite, I was only trying to point out how difficult it would be for "the average reader" (Whatever that means) to pick up and use effectively. I agree, reading that gave me a slew of ideas, I especially like that he included using the drive as a weapon (Very "Prefect").

No offence taken. I know my text is almost a self-parody of overly detailed analysis. But it is so fun to try to make the best analysis I possibly can even if it never matters much in-game. I have learned so much optics and physics from this project! (one reason for my broad education *is* rpgs - they are amazingly educational).

Drives as weapons are fun, but they also require that you have defeated nearby defences. Sure, you can almost cut an asteroid habitat in half with your Destroyer, but it is enough that there is one weapons emplacement drifting among the rubbish nearby that fires into your cooling system and you will go all Death Star...

nezumi wrote:

That sounds like a good way of tracking things, although it takes out any chance of random misses, evasive maneuvers and so on (or of the skill of the crew on board). It also seems to ignore something like a critical, penetrating hit which immediately hits a critical system.

A lot of the randomness is just abstracted away - each card represents several devices and weapons fire whole volleys of shots. Maybe we could include skill by adding bonus action cards? Penetrating hits could also be done through action cards: "Critical hit (Play when successfully damaging a target. The damage automatically destroys the target. Discard this card when played. ) "

I also noticed a big hole in my thinking: lasers can only be dodged, not defended against using point defenses. Good so far, but we need a game system that balances this advantage so lasers do not become guaranteed kill weapons. Any ideas?

Another problem that might require solving: the first player can launch a big volley with everything he got, blinding the second player on his turn. The second player might hence be unable to attack anything, leaving the first player a nice clean turn to fire his next volley. I think this can be balanced by allowing the second player to just fire his weapons at nothing in particular, still producing blinding flashes. It might also be possible to sacrifice some of the decoys to produce a blinding effect.

Extropian

Foucault Foucault's picture
Re: Starship Combat

While I like the idea of your starship combat game, I've got one very specific worry. It seems it works well for only 2 players, one for each faction. I've got four players in my group and I'd really like to see them all involved. Sure they could all have spaceships, but as the number of combatants rises so does the number of attacks and debris. If everyone destroys one item on their first turn then on turn 2 everyone needs 5 or more sensors to see anything. Realistically I understand that mechanic, but for enjoyment of the game I'm not so sure. Also, it's sort of unreasonable for my group of four to run around in four ships when they only have one pilot.

EDIT: I light of Arenamontanus last post on turn by turn blinding. What about simultaneous turn resolution? Instead of placing everything you want to do face up on the table, both players do it face down. They then proceed left to right, flipping over their cards and resolving them. Each card could have a "reaction" or "tracking" speed number, which determines which gets resolved first.

For instance Adam and Betty are playing, the first turn they each place down three cards. Once they are both done placing they each flip over, starting with their leftmost card.

First Card) Adam has a Sensor Sweep with at a speed of 2 and Betty shows a Sensor Drone with speed of 1. Since there are no attacks speed doesn't matter. The sensor drone is stronger, but slower.
Second Card) Adam shows a Missile Barrage of speed 2 and Betty shows a set of Point Defence Lasers of speed 5. So Betty deploys her PLDs first, so then they can be spent to intercept the Missiles. Had Adam used Beams the PDLs would have stuck around until used, they form a deterrent vs. using intercept-able weapons.
Third Card) Both players show Phased Array Lasers on Speed 3, so both get resolved. They each attack their opponents sensors, but since they resolve on the same speed the destruction doesn't happen until after they have been able to shoot.

I've got a couple other ideas to offer. Perhaps all non destroyed cards get returned to the players hand after the turn? Just because you have missiles doesn't mean you want to fire them every turn, especially if the opponent has Point Defences? Maybe your time would be better spent using Damage Control?

Which brings me to my last idea, Ships and Command and Control. Maybe ships should be played face up? So that the opponents knows what they are facing. If any of you have played Mansions of Madness it's got a good mechanic where all obvious stats are printed on the top of the monster cards and secret ones hidden on the bottom, and players are only allowed to look at the bottom once they've injured the monster. Perhaps the way to look at the bottom is a detailed Sensor Sweep on the enemy ship?

Finally I think con-straining the number of cards placed on a turn might be a good idea. It's a way to stop players from simply playing everything on the first turn. Each ship would get a C&C stat, and each card would have a cost, representing the amount of things a ship crew and their computers can do in an interval of time. If a Destroyer has a C&C of 3 and Sensor Sweep costs 1, Missiles cost 1, and PDL's cost 1 then the player could do all of those turn one. But if Phased Array Lasers cost 2 then they have to choose. It would also be a way to balance lasers.

Wow, that edit ended up being much longer than I hand anticipated. I'm just throwing ideas out there. I think this could be a very fun and fast little game.

R-Rep: 2

Arenamontanus Arenamontanus's picture
Re: Starship Combat

I guess the multiplayer issue is hard to do anything about. We should

Foucault wrote:

EDIT: I light of Arenamontanus last post on turn by turn blinding. What about simultaneous turn resolution? Instead of placing everything you want to do face up on the table, both players do it face down. They then proceed left to right, flipping over their cards and resolving them. Each card could have a "reaction" or "tracking" speed number, which determines which gets resolved first.

Initiative might help deal with the simultaneity problem. In my first sketch attacks were simultaneous, but that made them hard to resolve. Initiative also allows you to have more kinds of the same basic types of cards, making game strategies more complex. Buy some of those really fast attack beams, or get more cheap slow weapons?

Not certain about the sequential turning up of cards; it might be better to reveal all of them and then have the fastest devices act first, then the second fastest and so on.

Quote:
. Perhaps all non destroyed cards get returned to the players hand after the turn? Just because you have missiles doesn't mean you want to fire them every turn, especially if the opponent has Point Defences?

The reason for this is the visibility dynamics I get from my paper. Once a weapon has fired it is relatively easy to see (lots of IR) and much more vulnerable. I think you need to use special cards to bring them back to the relative safety of the hand which represents the cloud of currently un-tracked objects.

Quote:

Which brings me to my last idea, Ships and Command and Control. Maybe ships should be played face up? So that the opponents knows what they are facing.

I think this is problematic because one of the core issues in EP-style space combat is that ships are relatively vulnerable (even Destroyers - armour is weak), so they will need to hide as far as possible. Still, I also think it is fairly easy to identify ships before the battle is joined and sensors start getting blinded. Maybe we could have the rule that players must show all of their capital ships before start? (fighters and other stuff may be secret).

I have considered a "ship" card for an entire habitat. That card is unable to hide: it must always be face up, and will have some tough armour and point defences.

Quote:

Finally I think con-straining the number of cards placed on a turn might be a good idea. It's a way to stop players from simply playing everything on the first turn. Each ship would get a C&C stat, and each card would have a cost, representing the amount of things a ship crew and their computers can do in an interval of time.

As a simulation of real EP warfare this is problematic, since presumably ships could be running very large numbers of devices. But it might make for a better card game...

A lot of stuff to think about.

Extropian

InsidiousAlgorythm InsidiousAlgorythm's picture
Re: Starship Combat

I'm not even sure I like the idea of a card game... no that's not correct. The Idea of a separate (card) game involving EP ships combat sounds awesome! Not too sure how this could be used as a in game role playing supplemental, you're probably right anyway, not enough d100 action going on.

Are there any other RPGs out there that use the d100 mechanic and have fairly good ship to ship combat rules? Something like Elric or Stormbringers ship to ship could be ported easily enough. Just thinking out loud here mind you.

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

Messing around with these numbers, it really is amazing how huge the difference is between the ships. I'm trying to make up basic stats, standardized (approximately) on the lowest value in each category. Looking at it, I think any system will also have to account effectively for swarms.

Some quick questions;
Should delta-v be considered equivalent to the maximum speed (for the purpose of back-of-the-envelope calculations)?
What are the calculations for electrical power based off of? Is this just for the engine, or does it include things like life support? I assume these are the maximum for a momentary draw, not for the lifetime of the power plant, correct?
Is there a quick method to calculating the wattage requirements for things like railguns?

Thank you

Foucault Foucault's picture
Re: Starship Combat

Arenamontanus wrote:
But it might make for a better card game....

That definitely was the angle I was heading towards. But above everything else is the multiplayer problem for me. I think I'll be snagging my friend's copy of Rogue Trader, it's d100 and is entirely based around having a party that are the Important People on a starship that's somewhere in the frigate range. I'll let you guys know what I think of it, but I've played the Deathwatch and Dark Heresy versions of the game and quite enjoy them.

Arena should correct me, but I think that DeltaV is a combination of max speed and total fuel. If you want to arrive at a planet you need to accelerate to movement speed, cruise, and then stop yourself. So if I've got 10 units of DeltaV I can't use more than 5 to accelerate, otherwise I won't be able to stop. Also if you use that method then you don't have any margin for error or maneuvering.

R-Rep: 2

Smokeskin Smokeskin's picture
Re: Starship Combat

Max speed is a meaningless concept in space travel short of relativistic effects and fuel constraints (unless debris detection and collision avoidance or something similar is an issue of course)

Delta v is the effort needed to change from one trajectory to another. It is also used loosely as a spaceship's total capacity for trajectory change, ie its total fuel (though changes in total mass as reaction mass is used complicates things a bit), or conversely about how much fuel is needed for a long range flight. When used in the context of a limited time frame, what matters is the spaceship's max acceleration, as this determines how much delta v it can produce in the given time.

Smokeskin Smokeskin's picture
Re: Starship Combat

Max speed is a meaningless concept in space travel short of relativistic effects and fuel constraints (unless debris detection and collision avoidance or something similar is an issue of course)

Delta v is the effort needed to change from one trajectory to another. It is also used loosely as a spaceship's total capacity for trajectory change, ie its total fuel (though changes in total mass as reaction mass is used complicates things a bit), or conversely about how much fuel is needed for a long range flight. When used in the context of a limited time frame, what matters is the spaceship's max acceleration, as this determines how much delta v it can produce in the given time.

Smokeskin Smokeskin's picture
Re: Starship Combat

Max speed is a meaningless concept in space travel short of relativistic effects and fuel constraints (unless debris detection and collision avoidance or something similar is an issue of course)

Delta v is the effort needed to change from one trajectory to another. It is also used loosely as a spaceship's total capacity for trajectory change, ie its total fuel (though changes in total mass as reaction mass is used complicates things a bit), or conversely about how much fuel is needed for a long range flight. When used in the context of a limited time frame, what matters is the spaceship's max acceleration, as this determines how much delta v it can produce in the given time.

Arenamontanus Arenamontanus's picture
Re: Starship Combat

nezumi.hebereke wrote:

Should delta-v be considered equivalent to the maximum speed (for the purpose of back-of-the-envelope calculations)?

More or less. If I understand JSnead's intentions right, normally you launch using about a third to a half of the delta-v budget (but you will also have an orbital speed from the body you left: Earth moves at about 30 km/s), and then use about equal amount to slow down, leaving maybe a third to 25% for emergencies or battle course corrections. So you can go faster if you do slingshots, Oberth manoeuvres and gamble on somebody catching you with a tug-ship at your final destination, but it is often a bad idea.


Quote:
What are the calculations for electrical power based off of? Is this just for the engine, or does it include things like life support? I assume these are the maximum for a momentary draw, not for the lifetime of the power plant, correct?

You mean the engine power? They are based on the energy needed to produce the kinetic energy of the reaction mass at the stated exhaust velocity. It is not really electric energy in most cases, mainly heat (and then there is at least an equal amount of waste heat you need to just get rid of). The energy needed for powering life support is far, far smaller - I have a loose guess in the sensors section for about a kilowatt per person at the minimum.

Quote:

Is there a quick method to calculating the wattage requirements for things like railguns?

To launch a mass m projectile at velocity v, you need 0.5mv^2 J of energy. The railgun has efficiency 10% or so, so a first guess is E=5*m*v^2 J. So if you launch 1 kg projectiles at 10 km/s (slow), you need 5*10^8 J. A fast projectile at 100 km/s needs 5*10^10 J. That gets released in one burst, but if you have P watts of power and slowly charge up capacitors to shoot, then you can shoot P/E times per second. The Destroyer, if it could use 600 GW power, could shoot 1200 slow projectiles per second or 12 fast ones (but it would likely burn out the railguns since a sizeable fraction of the energy - those other 90% - would heat them).

I suspect at most (handwave) 10% of the total energy can be used to power railguns and lasers, since they require a much trickier cooling system than the drive.

Extropian

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

Smokeskin wrote:
Max speed is a meaningless concept in space travel short of relativistic effects and fuel constraints

That is precisely what I'm trying to do. I'm exploring my second idea, listed above, but that depends heavily on power management, so I'm trying to figure out how much power is available for a ship to draw on before it needs a refuel. I'm using delta v/acceleration*max engine power to calculate its total available energy. max engine power/max acceleration gives me an approximate number for the energy cost for accelerating that ship. I have numbers for life support. Once I calculate the energy costs for weapons, I'll have approximate numbers for basically all functions. Yes, they're back of the envelope, and I'm reducing everything to basic linear equations, but I think that's the sort of simplicity that would be necessary.

kindalas kindalas's picture
Re: Starship Combat

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Arenamontanus Arenamontanus's picture
Re: Starship Combat

nezumi.hebereke wrote:

That is precisely what I'm trying to do. I'm exploring my second idea, listed above, but that depends heavily on power management, so I'm trying to figure out how much power is available for a ship to draw on before it needs a refuel. I'm using delta v/acceleration*max engine power to calculate its total available energy. max engine power/max acceleration gives me an approximate number for the energy cost for accelerating that ship. I have numbers for life support. Once I calculate the energy costs for weapons, I'll have approximate numbers for basically all functions. Yes, they're back of the envelope, and I'm reducing everything to basic linear equations, but I think that's the sort of simplicity that would be necessary.

The formula I derived for total engine power was 4.9*a*M*I_sp Watts where a is the acceleration in m/s^2, M is the ship mass in kg and I_sp is the impulse of the engine. Since moving the ship is the heaviest task, when it is not fully accelerating there is going to be piles of energy left over (if you don't mind having to extend big radiators).

Extropian

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

Okay, so the calculations for power in your paper are just for power for maximum acceleration.

How did you originally derive the specific impulse?

edit: I'm looking for a shorthand way to figure out the maximum fuel available to a ship. I know you've already calculated that, to get the delta-v/acceleration/power calculations, but I'm concerned I may be going about deriving it incorrectly.

Arenamontanus Arenamontanus's picture
Re: Starship Combat

nezumi.hebereke wrote:
How did you originally derive the specific impulse?

It is dependent on the engine type (in turn, dependent on exhaust velocity and exhaust mass):
http://en.wikipedia.org/wiki/Specific_impulse#Examples
http://en.wikipedia.org/wiki/Spacecraft_propulsion#Table_of_methods
although I was helped by JSnead who posted the numbers he had used.

Quote:
edit: I'm looking for a shorthand way to figure out the maximum fuel available to a ship. I know you've already calculated that, to get the delta-v/acceleration/power calculations, but I'm concerned I may be going about deriving it incorrectly.

There are some complexities there due to the rocket equation (you need more fuel to accelerate a heavy ship such as one with full fuel tanks than a light ship with empty fuel tanks).

Extropian

nezumi.hebereke nezumi.hebereke's picture
Re: Starship Combat

So the specific impulse numbers are all gotten from somewhere else, not derived. That's sort of good to know. Are they listed somewhere? I didn't see an Isp column in any of the charts.

As for the fuel aspect, I'm hoping to handwave it as much as possible. Fuel has zero 'weight', but a heavier type of fuel requires more fuel 'points' to accelerate, and has a lower maximum amount. Are all of your delta-v numbers also from Jsnead/the book, or are they somehow derived statistics?

Smokeskin Smokeskin's picture
Re: Starship Combat

nezumi.hebereke wrote:
As for the fuel aspect, I'm hoping to handwave it as much as possible. Fuel has zero 'weight', but a heavier type of fuel requires more fuel 'points' to accelerate, and has a lower maximum amount.

When doing the fuel consumption and acceleration, it would probably be easiest to just assume fuel tanks were always half full.

Defending against attackers that have to make it home afterwards would lose their advantage though - they could afford to launch with very low fuel weight and have a an acceleration advantage.

Smokeskin Smokeskin's picture
Re: Starship Combat

Arenamontanus wrote:
OK, I give in: here is the current state of my writeup on the physics of EP space combat.

http://www.aleph.se/EclipsePhase/EP%20naval%20strategy.pdf

Very interesting stuff.

On railgun damage, I'm not sure Newton's penetration approximation apply. At these high velocities you can't just stop a railgun slug. The kinetic energy in a 10 km/s projectile is enough to heat up around 70 times its own mass of metal to boiling point, so when it impacts something it is either going deeper than it its own length ("breaking" Newton's penetration approximation) or more likely it'll vaporize itself and what it impacts with and generate a massive explosion from the overpressure. Even a 100kg slug at 10 km/s gives a 1 kiloton explosion, about 1/15th of the Hiroshima nuclear bomb.

I won't pretend to understand exactly what does happen, but Newton's approximation doesn't apply here.

Arenamontanus Arenamontanus's picture
Re: Starship Combat

Smokeskin wrote:
On railgun damage, I'm not sure Newton's penetration approximation apply. At these high velocities you can't just stop a railgun slug. The kinetic energy in a 10 km/s projectile is enough to heat up around 70 times its own mass of metal to boiling point, so when it impacts something it is either going deeper than it its own length ("breaking" Newton's penetration approximation) or more likely it'll vaporize itself and what it impacts with and generate a massive explosion from the overpressure.

Good point! I still think Newton is a good start, since it anyway shows that heavy armor is not going to be that great. Widely separated layers of Whipple shields work much better against hypervelocity.

Extropian

Smokeskin Smokeskin's picture
Re: Starship Combat

It seems reasonable that any mass in the path of a big rail gun slug gets turned into a rapidly exanding ball of plasma, which would make the best armor strategy no armor - you just have to deal with the hole and hope the kinetic energy bleed explosion isn't too bad.

But then attackers would start loading their railguns with slugs that broke up into a great number of flechettes, ensuring many hits and as much kinetic energy bleed as possible. Launching disks flat end first could be a good idea also - if you could somehow get a proper spread, a stack of them, like coins in a shotgun, could work too.

Which again changes armor preference...

Arenamontanus Arenamontanus's picture
Re: Starship Combat

http://en.wikipedia.org/wiki/Whipple_shield

The offensive trick is of course to launch two projectiles after each other to penetrate through the hole the first made. But if the target is accelerating, it is harder to achieve.

Extropian

Ratchet2012 Ratchet2012's picture
Re: Starship Combat

^_^ InsidiousAlgorythm your trolling! !!LOL TROLL!!

Ratchet2012 Ratchet2012's picture
Re: Starship Combat

nezumi.hebereke wrote:
That sounds like a good way of tracking things, although it takes out any chance of random misses, evasive maneuvers and so on (or of the skill of the crew on board). It also seems to ignore something like a critical, penetrating hit which immediately hits a critical system.

i like this idea, simple... but ya lets try and tone down the phisics some, i got to much of that where i work (U.S.A.F. Air Force if you want to know...) ill see if some basic math can be used insted of collage level ^_^

InsidiousAlgorythm InsidiousAlgorythm's picture
Re: Starship Combat

Ratchet2012 wrote:
^_^ InsidiousAlgorythm your trolling! !!LOL TROLL!!

*Yawn*

I said what I had to say to you, and this is all you could come back with? Get back to me when you have something intelligent to say.

RustedPantheress RustedPantheress's picture
*resleeves the thread*

*resleeves the thread*
Did nobody ever play Mission Critical? The ships had more or less the same problems: Limited maneuverability, it was hard to hide your presence, they could be fragile, etc. Combat was done with automated drones, while the ships had some limited point defense, and maybe a few long-range weapons.
This can actually be done pretty easily in EP. The main thing is generating the numbers.

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NewtonPulsifer NewtonPulsifer's picture
Regarding a double shot at as

Regarding a double shot as a whipple shield weakness - make sure to spin the shield.

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Solar Solar's picture
It occurs to me that a lot of

It occurs to me that a lot of the debate over how ship combat in EP works assumes the use of AIs. But AIs aren't actually faster information processors than transhuman infolife, are going to be far less flexible and intelligent a lot of the time, and also are far more susceptible to mesh based intrusion.

Also remember that internal ships networks may not be entirely hardwire based. As far as I know, hardwire systems build up more heat than wireless systems, and when you are fighting in space, heat is a problem. There's also the communication that you'll have to maintain with your drones and other ships, and QE bits are still scarce enough that I can't see every drone using them. So wireless, and thus hackable, systems are still present. I can see ships operating some systems on wireless and some on hardware. A concerted hacking attempt piggy-backing off deployed drones seems somewhat doable.

Also in a post-fall solar system, AIs as military technology are going to be quite rare. After all, people don't really trust AIs a huge amount and consider them susceptible to compromising Titan attacks. The most powerful navy around is the Jovian one, and they don't use AIs for any significant tasks, probably relying on regular humans upgraded with speed and information processing implants, a definite rarity amongst the Jovians, but a necessary one to keep up with their enemies information processing tech.

EP ship crews are probably partially infolife, sleeved into the ship, to aid directly in the operation of ship systems, partially various morph types involved in maintenance and possibly even the operation of other systems by skinlink and so on (thus allowing quick detachment from compromised systems), and combat itself not being done entirely by software but instead by transhumans with Speed 3 or 4 operating either as mesh entities or biomorphs in full VR.

And the drones themselves are probably piloted by forks of various pilots working together with the original pilot who directs the forks from back at base. The Jovians actually use physical pilots in their drones, very very dangerous, but this actually gives them an edge, as well trained transhumans, even Jovians, with the correct implants (which the Jovians do use in such instances) are capable of combating against AI and infolife drone operators.

Seriously, I think this is well worth remembering: there is nothing a non-seed AI in EP can do that a transhuman with the correct morph and implants, probably in a full VR simulation, cannot do. An AI is just an inflife with about the intellectual power of a Delta Fork, they aren't uniquely good at anything. In fact, they are generally considered to be inferior to infolifes or even physically sleeved transhumans.

Crazy Tom Crazy Tom's picture
There's some neat work on

There's some neat work on realistic space combat that's been done by Blue Max Studios:

http://bluemaxstudio.blogspot.ca/2011/10/space-combat-in-black-desert-ac...

I think a lot of it crosses over to EP very well. Especially the Detection, Determination, Preparation phases. The only thing that might be different is the manoeuvring and engagement, since EP has far more powerful propulsion and weapons technology.

ericbrooke ericbrooke's picture
Coriolis

I like the approach that Coriolis RPG takes.. with allocated ship positions so all players can get involved

Eric Brooke

o11o1 o11o1's picture
Crazy Tom wrote:There's some

Crazy Tom wrote:
There's some neat work on realistic space combat that's been done by Blue Max Studios:

http://bluemaxstudio.blogspot.ca/2011/10/space-combat-in-black-desert-actual.html

I think a lot of it crosses over to EP very well. Especially the Detection, Determination, Preparation phases. The only thing that might be different is the manoeuvring and engagement, since EP has far more powerful propulsion and weapons technology.

I think this is the correct link: http://bluemaxstudios.blogspot.com/2011/10/space-combat-in-black-desert-actual.html

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