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 12-07-2022, 06:09 AM   #31
Varyon
 
Join Date: Jun 2013
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Rupert View Post
You seem to be assuming that dice of blast damage are converted directly into fragment damage on a one-to-one basis, which is questionable.
Actually, I'm assuming dice of blast damage get converted directly into fragmentation damage on a one-to-two basis - that is, you lose 1d cr ex to gain [2d]. This is primarily based off a grenade from HT that has a removable fragmentation jacket, but IIRC from back when I came up with the equivalence, it seems to work for other explosives as well. It's at least a more usable rule than what we have now (which is a big fat Nothing Sandwich).
__________________
GURPS Overhaul
Varyon is online now   Reply With Quote
Old 12-07-2022, 07:11 AM   #32
sir_pudding
Wielder of Smart Pants
 
sir_pudding's Avatar
 
Join Date: Aug 2004
Location: Ventura CA
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Varyon View Post
It's at least a more usable rule than what we have now (which is a big fat Nothing Sandwich).
The casualty radius of a fragmentation munition is almost always available data, and fragmentation damage in GURPS is directly related to radius.
sir_pudding is offline   Reply With Quote
Old 12-07-2022, 07:28 AM   #33
Varyon
 
Join Date: Jun 2013
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by sir_pudding View Post
The casualty radius of a fragmentation munition is almost always available data, and fragmentation damage in GURPS is directly related to radius.
If you're working with existing munitions, perhaps. When you're modifying things that historically only used something like TL3 serpentine to instead use TL5 improved black powder (or TL6+ high explosives), creating stats for munitions that never existed (because your campaign takes place in an alternate/secret history or doesn't even take place on Earth at all), and so forth, it's better to have something than nothing. If you have a better rule to work out how much explosive damage is used up to produce a certain amount of fragmentation, I'm all ears (or eyes, I suppose, this being a text-based forum). Until then, I'll stick with "1 point of explosive damage sacrificed for every 2 points of fragmentation damage, fragmentation damage dice cannot exceed remaining explosive damage dice."
__________________
GURPS Overhaul
Varyon is online now   Reply With Quote
Old 12-07-2022, 10:04 AM   #34
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Varyon View Post
If you're working with existing munitions, perhaps. When you're modifying things that historically only used something like TL3 serpentine to instead use TL5 improved black powder (or TL6+ high explosives), creating stats for munitions that never existed (because your campaign takes place in an alternate/secret history or doesn't even take place on Earth at all), and so forth, it's better to have something than nothing. If you have a better rule to work out how much explosive damage is used up to produce a certain amount of fragmentation, I'm all ears (or eyes, I suppose, this being a text-based forum). Until then, I'll stick with "1 point of explosive damage sacrificed for every 2 points of fragmentation damage, fragmentation damage dice cannot exceed remaining explosive damage dice."
If you want something that makes sense you'll need a lot more than some rule for how much blast damage a warhead loses to create fragmentation.

For starters, in GURPS the odds of getting hit do not change with warhead size or warhead design (so a crappy cast-steel WWI hand grenade has the same number of fragments as a modern one with a pre-scored wire fragmentation jacket). Aside from any issue with reality this means that the effective casualty zone is the same for almost all warheads because it's the area in which 50% of the occupants are expected to be casualties (assuming even distribution, etc.) or the range at which there's a 50% chance of getting hit, depending on who's definition you use (again with a bunch of assumptions, like the targets being standing in the open, etc.), because warhead size and design does not affect hit chance.
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is online now   Reply With Quote
Old 12-07-2022, 11:00 AM   #35
Fred Brackin
 
Join Date: Aug 2007
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Rupert View Post

For starters, in GURPS the odds of getting hit do not change with warhead size or warhead design (so a crappy cast-steel WWI hand grenade has the same number of fragments as a modern one with a pre-scored wire fragmentation jacket). .
......and the maximum number of hits in a human-shaped area appears to be 5 but each hit will do damage like a swing from a sword from a strong man (2D).

Reality testing makes the number of fragments a hundred or more but they're from pieces of metal the size of a fingernail that are stopped by quarter inch plywood (cover DR of no more than 1).

The fragmentation rules get better with size but still penetrate armor too well. WWI helmets with DR no more than 3 against bullets were considered adequate against fragments even from full-sized artillery.

I think Varyon's HT grenade with the removeable jacket was the Diehl which confuses matters further by throwing ball bearings instead of fragments.

Anyway, trading concussion for fragmentation is not where I'd begin re-doing the rules.
__________________
Fred Brackin
Fred Brackin is offline   Reply With Quote
Old 12-07-2022, 11:00 AM   #36
Varyon
 
Join Date: Jun 2013
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Rupert View Post
If you want something that makes sense you'll need a lot more than some rule for how much blast damage a warhead loses to create fragmentation.

For starters, in GURPS the odds of getting hit do not change with warhead size or warhead design (so a crappy cast-steel WWI hand grenade has the same number of fragments as a modern one with a pre-scored wire fragmentation jacket). Aside from any issue with reality this means that the effective casualty zone is the same for almost all warheads because it's the area in which 50% of the occupants are expected to be casualties (assuming even distribution, etc.) or the range at which there's a 50% chance of getting hit, depending on who's definition you use (again with a bunch of assumptions, like the targets being standing in the open, etc.), because warhead size and design does not affect hit chance.
"All models are wrong, but some are useful."

Basically, we currently have some rules for how fragmentation works. We do not have any rules for how much fragmentation you get out of a purpose-built explosive device that isn't already statted out. My suggestion gives you rules for the latter. If you want more realistic/logical/whatever rules for how fragmentation behaves, honestly that's a completely separate discussion, and would apply to all fragmentation stats, both those already published and those that need to be generated in some way. Such rules would certainly be welcome, provided they can be made to be gameable, of course.
__________________
GURPS Overhaul
Varyon is online now   Reply With Quote
Old 12-07-2022, 11:57 AM   #37
Fred Brackin
 
Join Date: Aug 2007
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Varyon View Post
"All models are wrong, but some are useful."

Basically, we currently have some rules for how fragmentation works. We do not have any rules for how much fragmentation you get out of a purpose-built explosive device that isn't already statted out. My suggestion gives you rules for the latter..
I'm afraid your rules conform to reality in only a few cases. As a general thing they do not conform to carefully researched Gurps rules in many, many cases.

If you look at all the other grenades in HT espcially comparing dedicated fragmentation devices and concussion only you do not see evidence that the frags are giving up any concussion.

This was also explicitly the case in Ve2's warhead design rules and UT 4e's modular warhead system. HE (w/frag) and HEC (without) do the same amount of concussion.

I think the Diehl is an outlier and not a prime model.
__________________
Fred Brackin
Fred Brackin is offline   Reply With Quote
Old 12-07-2022, 12:21 PM   #38
Varyon
 
Join Date: Jun 2013
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Fred Brackin View Post
If you look at all the other grenades in HT espcially comparing dedicated fragmentation devices and concussion only you do not see evidence that the frags are giving up any concussion.
I'll have to look up the relevant information again when I get home; it's been a few years since I came up with the equivalence, but ISTR looking up several explosives and finding a general agreement with the way the Diehl (I believe that is indeed the grenade I based things off of) functioned.

Quote:
Originally Posted by Fred Brackin View Post
This was also explicitly the case in Ve2's warhead design rules and UT 4e's modular warhead system. HE (w/frag) and HEC (without) do the same amount of concussion.
I can't speak to 3e, but I know in 4e HE generally has a smaller explosion than HEC of the same size (including in UT; I'm not sure what you're referring to as the "modular warhead system," but I remember the HE vs HEC options for typical warheads have HEC dealing more cr ex damage) - but this may simply be due to the former generally containing less explosive payload than the latter. But needing to "pay for" the fragmentation damage with explosive damage is just physics - the energy to produce and propel the fragments has to come from somewhere. It's certainly possible this is handwaved away in most stats, with the Diehl being an exception (perhaps because the authors decided it was below GURPS resolution)

Quote:
Originally Posted by Fred Brackin View Post
I think the Diehl is an outlier and not a prime model.
If you've got a working model, feel free to share.
__________________
GURPS Overhaul
Varyon is online now   Reply With Quote
Old 12-07-2022, 12:49 PM   #39
Anthony
 
Join Date: Feb 2005
Location: Berkeley, CA
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Varyon View Post
I can't speak to 3e, but I know in 4e HE generally has a smaller explosion than HEC of the same size (including in UT; I'm not sure what you're referring to as the "modular warhead system," but I remember the HE vs HEC options for typical warheads have HEC dealing more cr ex damage) - but this may simply be due to the former generally containing less explosive payload than the latter.
Yeah, it's pretty much just that.

GURPS explosion rules are really bad at modeling real situations, concussion is much worse at killing people and much better at destroying structures than the GURPS rules imply, the scaling is wrong, and shrapnel damage is in large part determined by the design of your fragmentation case.
__________________
My GURPS site and Blog.
Anthony is offline   Reply With Quote
Old 12-07-2022, 08:44 PM   #40
Fred Brackin
 
Join Date: Aug 2007
Default Re: Explosive Arrows and Ancient Rockets

Quote:
Originally Posted by Varyon View Post
I'l

I can't speak to 3e, but I know in 4e HE generally has a smaller explosion than HEC of the same size (including in UT; I'm not sure what you're referring to as the "modular warhead system," but I remember the HE vs HEC options for typical warheads have HEC dealing more cr ex damage) - but this may simply be due to the former generally containing less explosive payload than the latter.

If you've got a working model, feel free to share.
The generic notes in HT do have HEC using a larger percentage of the warhead's total weight with roughly 10% for HE and 15% for HEC. However, considering the relative densities of steel and high explosives the mass of the casing is still mostly there. It's just that the HEC casing mostly goes to dust rather than making fragments. It's not that the casing doesn't soak up as much KE.

As to "working models" i don't even have a problem that needs solving. The world is full of complex systems that will not yield useful results when reduced to simplified math. I trust David's research and I trust HANS research and feel no need for a unified boom! theory. There are and will continue to be eccentric behaviors among specified RW devices that will screw up any simplified rule if attempts to fit them in are forced on the system.
__________________
Fred Brackin
Fred Brackin is offline   Reply With Quote
Reply

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 05:43 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2023, vBulletin Solutions, Inc.