Steve Jackson Games - Site Navigation
Home General Info Follow Us Search Illuminator Store Forums What's New Other Games Ogre GURPS Munchkin Our Games: Home

Go Back   Steve Jackson Games Forums > Roleplaying > GURPS

Reply
 
Thread Tools Display Modes
Old 10-27-2011, 08:15 AM   #1
vicky_molokh
GURPS FAQ Keeper
 
vicky_molokh's Avatar
 
Join Date: Mar 2006
Location: Kyv, Ukraine
Default GURPS Spaceships: Murphies, their fixes and alternatives

Greetings, all!

Let me begin by saying that GURPS Spaceships is a fascinating project/series, and I definitely like it, and haven't seen a playable alternative that is better (but Rogue Trader comes to mind, for the specific case of WH40K). I also pointed out some of its parts that I see as flawed or incomplete, and occasionally posted my ideas how to fix them.

But I'm also curious what things other people see as murphies, and what fixes they see as viable (and which ones they do not see as possible to fix at all).

Thanks in advance!
__________________
Vicky 'Molokh', GURPS FAQ and uFAQ Keeper
Also, GURPS Discord is a nice place for (faster) Q&A and overall GURPS dicussion.
vicky_molokh is offline   Reply With Quote
Old 10-27-2011, 08:52 AM   #2
Ulzgoroth
 
Join Date: Jul 2008
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

I think the biggest and fatal fault is the way it uses standard GURPS rapid fire rules for attacks from batteries of weapons and for attacks spread over multiple seconds. This is particularly bad whenever missiles and point defense are involved. This has a few knock-on sub-murphies, but those would likely vanish in the process of getting rid of the core problem.

Spaceships combat has two-axis scalability (time and space). Unfortunately, it doesn't necessarily conserve important features of combat over scale changes. Ignoring the time-scaling issues with weapons previously noted, there's a problem with Dodge. To be allowed to dodge under either combat system, your ship has to use a certain amount of thrust. How much is dependent not on any property of your ship or the attack to be dodged, but rather on the combat scale in use. I'd suggest simply setting a constant minimum delta-V that must be burned in a turn to allow a dodge, and allowing that to be burned whether or not it's sufficient for the ship to accelerate significantly at the combat scale.

The economics of building spaceships, or of anything built by spaceships factory systems, are pretty much absurd. Occasionally outright physics-breaking, as in the refinery which can electrolyze water fast enough that it generates more fuel than a fuel cell powering it consumes.

There are some smaller peculiarities:
-What's the rate of fire of Spaceships weapons in regular GURPS combat?
-Should any imperfect landing be catastrophic? A crash landing does 6dx3xHPx0.1, which averages 6.3xHP. Any other landing is non-damaging.
-The description of Steerage Cargo calls into question what regular cargo space is. And by talking about carrying livestock, also the rules for life support capacity.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.
Ulzgoroth is offline   Reply With Quote
Old 10-27-2011, 08:58 AM   #3
vicky_molokh
GURPS FAQ Keeper
 
vicky_molokh's Avatar
 
Join Date: Mar 2006
Location: Kyv, Ukraine
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by Ulzgoroth View Post
I think the biggest and fatal fault is the way it uses standard GURPS rapid fire rules for attacks from batteries of weapons and for attacks spread over multiple seconds. This is particularly bad whenever missiles and point defense are involved. This has a few knock-on sub-murphies, but those would likely vanish in the process of getting rid of the core problem.
Seconded. Though personally, I would prefer a complete rehaul of 4e rapid-fire rules. They're very un-generic, and unusual cases underscore this fact.

Quote:
Originally Posted by Ulzgoroth View Post
Spaceships combat has two-axis scalability (time and space). Unfortunately, it doesn't necessarily conserve important features of combat over scale changes. Ignoring the time-scaling issues with weapons previously noted, there's a problem with Dodge. To be allowed to dodge under either combat system, your ship has to use a certain amount of thrust. How much is dependent not on any property of your ship or the attack to be dodged, but rather on the combat scale in use. I'd suggest simply setting a constant minimum delta-V that must be burned in a turn to allow a dodge, and allowing that to be burned whether or not it's sufficient for the ship to accelerate significantly at the combat scale.
I solve the problem by giving a fixed choice of these scales for any given campaign (helps adjust campaign feel too . . . though neither campaign actually started, playtesting showed that it helps).

Quote:
Originally Posted by Ulzgoroth View Post
The economics of building spaceships, or of anything built by spaceships factory systems, are pretty much absurd. Occasionally outright physics-breaking, as in the refinery which can electrolyze water fast enough that it generates more fuel than a fuel cell powering it consumes.
As I said before, economics are one of the few things at which GURPS isn't awesome. I suppose this one will take long rebalancing to fix.

Quote:
Originally Posted by Ulzgoroth View Post
There are some smaller peculiarities:
-What's the rate of fire of Spaceships weapons in regular GURPS combat?
I usually say that the rate derived from the scale ratios.
Quote:
Originally Posted by Ulzgoroth View Post
-Should any imperfect landing be catastrophic? A crash landing does 6dx3xHPx0.1, which averages 6.3xHP. Any other landing is non-damaging.
Tackled, and likely fixed by changing the velocity.
Quote:
Originally Posted by Ulzgoroth View Post
-The description of Steerage Cargo calls into question what regular cargo space is. And by talking about carrying livestock, also the rules for life support capacity.
Seen it discussed, and think that a paragraph or two of GM rulings can fix it. Just stick to those rulings after posting them first.
__________________
Vicky 'Molokh', GURPS FAQ and uFAQ Keeper
Also, GURPS Discord is a nice place for (faster) Q&A and overall GURPS dicussion.
vicky_molokh is offline   Reply With Quote
Old 10-27-2011, 09:03 AM   #4
cmdicely
 
Join Date: Aug 2004
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Spaceships uses 2D "tactical" combat, and space is actually 3D, which breaks realism badly for pretty much everything tactical about Spaceships combat, particularly with more than two objects of interest on the map (combatant vessels plus any missiles, etc.)

There's no easy fix for this, unless you consider "adapt Spaceships tactical combat to 3D" to be easy (its fairly straightforward if you steal the 3D play aids and adapt a few rules from Ad Astra's Squadron Strike, which is pretty close to a 3D analog of the SS3 tactical system to start with.)
cmdicely is offline   Reply With Quote
Old 10-27-2011, 09:13 AM   #5
vicky_molokh
GURPS FAQ Keeper
 
vicky_molokh's Avatar
 
Join Date: Mar 2006
Location: Kyv, Ukraine
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by cmdicely View Post
Spaceships uses 2D "tactical" combat, and space is actually 3D, which breaks realism badly for pretty much everything tactical about Spaceships combat, particularly with more than two objects of interest on the map (combatant vessels plus any missiles, etc.)

There's no easy fix for this, unless you consider "adapt Spaceships tactical combat to 3D" to be easy (its fairly straightforward if you steal the 3D play aids and adapt a few rules from Ad Astra's Squadron Strike, which is pretty close to a 3D analog of the SS3 tactical system to start with.)
3D-izing Spaceships isn't exactly problematic from a rules-adaptation PoV. It is somewhat difficult from the playing PoV (you need a software aid, which, while trivial to make from a scripting PoV, will scare off many people). It also might be problematic from the balance PoV: Guns suddenly become less useful due to the enemies having many more [3D] 'hexes' to use.

Also, I will repeat my question from the other thread: would you play Spaceships 3D if such a software aid were available? (Not just cmdicey, the question is addressed to everyone.)
__________________
Vicky 'Molokh', GURPS FAQ and uFAQ Keeper
Also, GURPS Discord is a nice place for (faster) Q&A and overall GURPS dicussion.
vicky_molokh is offline   Reply With Quote
Old 10-27-2011, 09:24 AM   #6
Ulzgoroth
 
Join Date: Jul 2008
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by vicky_molokh View Post
Seconded. Though personally, I would prefer a complete rehaul of 4e rapid-fire rules. They're very un-generic, and unusual cases underscore this fact.
They've definitely got some basic problems (the 'can't hit the broad side of a barn' issue), but in this case it's been argued that the problem is more that the rapid fire rules are being profoundly misused rather than being the problem themselves, and I think there's something to that.
Quote:
Originally Posted by vicky_molokh View Post
I solve the problem by giving a fixed choice of these scales for any given campaign (helps adjust campaign feel too . . . though neither campaign actually started, playtesting showed that it helps).
I can see how that would prevent an in-play consistency failure. I don't find it satisfactory as a solution, though. The delta-V cost of dodging a laser shouldn't be campaign-specific unless you're playing with radically changed physics.
Quote:
Originally Posted by vicky_molokh View Post
I usually say that the rate derived from the scale ratios.
It should be soluble along those lines (I and others have offered models), though it's a little more involved than that if you want it to be consistent. You can't just say a VRF weapon is RoF 5, because space combat shooting is based on at least 3 seconds of aim. Also, how you deal with this suggests things about how you should deal with the RoF problem.
Quote:
Originally Posted by vicky_molokh View Post
Tackled, and likely fixed by changing the velocity.
Likely, though I don't see the actual fix anyplace. Probably want to leave the 0.1 mps crash as a 'things go horribly wrong' option.
Quote:
Originally Posted by vicky_molokh View Post
Seen it discussed, and think that a paragraph or two of GM rulings can fix it. Just stick to those rulings after posting them first.
Undoubtedly, but what should they be? There's a major weight penalty on Steerage Cargo, so it's got to do something.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.
Ulzgoroth is offline   Reply With Quote
Old 10-27-2011, 09:27 AM   #7
cmdicely
 
Join Date: Aug 2004
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by Ulzgoroth View Post
Spaceships combat has two-axis scalability (time and space). Unfortunately, it doesn't necessarily conserve important features of combat over scale changes. Ignoring the time-scaling issues with weapons previously noted, there's a problem with Dodge. To be allowed to dodge under either combat system, your ship has to use a certain amount of thrust.
Are you sure? The only limit regarding thrust I see in the Basic system is that you have to acheive at least a +0 acceleration bonus (p. 60). AFAICT from the rules on Acceleration Bonus (p. 54) if you don't Drift and expend any thrust at all, you have a +0 bonus (the table provides a thrust amount needed for each +2 of bonus, and you have to halve that to get a +1.)

OTOH, the SS3 requirement for a velocity change of 1 hex/turn does create this problem.

Quote:
How much is dependent not on any property of your ship or the attack to be dodged, but rather on the combat scale in use. I'd suggest simply setting a constant minimum delta-V that must be burned in a turn to allow a dodge, and allowing that to be burned whether or not it's sufficient for the ship to accelerate significantly at the combat scale.
Since the amount of delta-V a ship can burn in a turn is timescale-dependent, doing this either leaves dodge ability as scale dependent, or creates a new Murphy wherein in Dodging a ship can burn fuel more rapidly than its engines otherwise allow. So I'm not sure this improves anything.

What you need to do is to adopt a constant number of G's of thrust and a constant time (like 1 minute, not number of turns, like 1 turn) over which it must be applied in order to qualify for dodge, allowing the time to be made up of a sequence of turns prior to the attack (including the turn of the attack) if the time is longer than the shortest turn scale.
cmdicely is offline   Reply With Quote
Old 10-27-2011, 09:56 AM   #8
Ulzgoroth
 
Join Date: Jul 2008
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by cmdicely View Post
Are you sure? The only limit regarding thrust I see in the Basic system is that you have to acheive at least a +0 acceleration bonus (p. 60). AFAICT from the rules on Acceleration Bonus (p. 54) if you don't Drift and expend any thrust at all, you have a +0 bonus (the table provides a thrust amount needed for each +2 of bonus, and you have to halve that to get a +1.)

OTOH, the SS3 requirement for a velocity change of 1 hex/turn does create this problem.
Interesting, I hadn't seen the +0 there, but I think there's...well, two problems with that, actually. I don't think there's a definition anywhere of how you achieve a +0 acceleration bonus, for the smaller one.

The larger one is that every maneuver other than the two drifts requires you to accelerate. And when I asked about Hold Course, which is the only maneuver that fails to specify how much you have to accelerate, I got back that it required an acceleration bonus as well.
Quote:
Originally Posted by cmdicely View Post
Since the amount of delta-V a ship can burn in a turn is timescale-dependent, doing this either leaves dodge ability as scale dependent, or creates a new Murphy wherein in Dodging a ship can burn fuel more rapidly than its engines otherwise allow. So I'm not sure this improves anything.

What you need to do is to adopt a constant number of G's of thrust and a constant time (like 1 minute, not number of turns, like 1 turn) over which it must be applied in order to qualify for dodge, allowing the time to be made up of a sequence of turns prior to the attack (including the turn of the attack) if the time is longer than the shortest turn scale.
I agree that you do need to require a minimum thrust as well as a minimum delta-V, I should have mentioned that constraint.

I don't think you need to worry about the time-scale of the burn, because it will necessarily be shorter than the 20 second turn and possibly shorter than the 1-second turn.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.
Ulzgoroth is offline   Reply With Quote
Old 10-27-2011, 10:36 AM   #9
Langy
 
Join Date: May 2008
Location: CA
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by Ulzgoroth View Post
I agree that you do need to require a minimum thrust as well as a minimum delta-V, I should have mentioned that constraint.

I don't think you need to worry about the time-scale of the burn, because it will necessarily be shorter than the 20 second turn and possibly shorter than the 1-second turn.
The reason that the amount of delta-V changes when timescale changes is that the amount of time over which you need to dodge changes.

For example, if you need to dodge ten laser bolts over ten seconds, you need to expend x Delta-V. If you need to dodge one hundred laser bolts over one hundred seconds, you need to expend 10x Delta-V, because you need to dodge ten times the number of laser bolts spread over ten times the amount of time, same as if you were dodging each 10 laser bolt burst every ten seconds individually.

This is not a Murphy's Rule.
Langy is offline   Reply With Quote
Old 10-27-2011, 10:50 AM   #10
Ulzgoroth
 
Join Date: Jul 2008
Default Re: GURPS Spaceships: Murphies, their fixes and alternatives

Quote:
Originally Posted by Langy View Post
The reason that the amount of delta-V changes when timescale changes is that the amount of time over which you need to dodge changes.

For example, if you need to dodge ten laser bolts over ten seconds, you need to expend x Delta-V. If you need to dodge one hundred laser bolts over one hundred seconds, you need to expend 10x Delta-V, because you need to dodge ten times the number of laser bolts spread over ten times the amount of time, same as if you were dodging each 10 laser bolt burst every ten seconds individually.

This is not a Murphy's Rule.
That part of it isn't, though it has some peculiarities.

The part where the acceleration you need to use is proportional to the distance scale over the square of the time scale, however, is.
__________________
I don't know any 3e, so there is no chance that I am talking about 3e rules by accident.
Ulzgoroth is offline   Reply With Quote
Reply

Tags
house rules, houserules, murphy's rules, spaceships

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Fnords are Off
[IMG] code is Off
HTML code is Off

Forum Jump


All times are GMT -6. The time now is 10:27 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2018, vBulletin Solutions, Inc.