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 04-03-2020, 01:32 PM   #1
Michael Thayne
 
Michael Thayne's Avatar
 
Join Date: May 2010
Default [Spaceships] Rationalizing facing and arcs of fire in tactical combat

The handling of facing and arcs of fire in spaceships has some odd features, especially in tactical combat. So I've decided to try to draft a somewhat improved set of rules. Feedback welcome.

The basic approach here is to think of ships in terms of o'clock directions, e.g. 12 o'clock is straight forward, 6 o'clock is straight backwards, etc. The even numbers will always correspond to faces of the tactical hex grid, while the odd numbers will always correspond to corners of the tactical hex grid. Hull sections are as follows: "front" is from 10 o'clock to 2 o'clock; "central" is from 2 o'clock to 4 o'clock and 8 o'clock to 10 o'clock, and "rear" is from 4 o'clock to 8 o'clock.

All weapons need to be located at an o'clock position. Fixed mounts have a 60 arc of fire (e.g. from 11 o'clock to 1 o'clock) while turrets have a 180 arc of fire (e.g. from 6 o'clock to 12 o'clock). These ranges are always inclusive on both ends (e.g. a fixed mount pointing towards 3 o'clock with range 1 will be able to fire at targets in either of two hexes).

Which hull section an attacker can target depends on which o'clock position it is coming from:
  • 11 o'clock to 1 o'clock (exclusive): front only
  • 1 o'clock to 3 o'clock or 9 o'clock to 11 o'clock (inclusive): front or central hull
  • 3 o'clock to 5 o'clock or 7 o'clock to 9 o'clock (inclusive): central or rear hull
  • 5 o'clock to 7 o'clock (exclusive: rear hull only
Note that I've defined these ranges such that an attacker exactly located at a ship's 3 o'clock or 9 o'clock will be able to target any hull section, but having a choice of two hull sections to attack will be much more common.
Michael Thayne is offline   Reply With Quote
Old 04-03-2020, 02:18 PM   #2
Ulzgoroth
 
Join Date: Jul 2008
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

It's rather weird to make turret arcs more restrictive than historical naval types. Centerline turrets would usually have arcs that span more than 180 degrees, and full 360 coverage was possible and is more possible in space where there's no reason to have a tall superstructure blocking part of the arc.
__________________
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 04-03-2020, 02:28 PM   #3
Michael Thayne
 
Michael Thayne's Avatar
 
Join Date: May 2010
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Ulzgoroth View Post
It's rather weird to make turret arcs more restrictive than historical naval types. Centerline turrets would usually have arcs that span more than 180 degrees, and full 360 coverage was possible and is more possible in space where there's no reason to have a tall superstructure blocking part of the arc.
This is mostly intended as a concession to the 2D nature of the GURPS Spaceships rules. In a full 3D system you'd want to let each turret cover a half-sphere arc. I realize this complicated because a real spaceship would be able to roll to maximize the number of turrets that can fire at a given target, but (1) while that might effectively give you a full-sphere arc in some combat situations, it wouldn't work in all situations and (2) modeling it realistically is more complexity than I care to deal with. YMMV.
Michael Thayne is offline   Reply With Quote
Old 04-03-2020, 06:10 PM   #4
Michael Thayne
 
Michael Thayne's Avatar
 
Join Date: May 2010
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Michael Thayne View Post
Which hull section an attacker can target depends on which o'clock position it is coming from:
  • 11 o'clock to 1 o'clock (exclusive): front only
  • 1 o'clock to 3 o'clock or 9 o'clock to 11 o'clock (inclusive): front or central hull
  • 3 o'clock to 5 o'clock or 7 o'clock to 9 o'clock (inclusive): central or rear hull
  • 5 o'clock to 7 o'clock (exclusive: rear hull only
Note that I've defined these ranges such that an attacker exactly located at a ship's 3 o'clock or 9 o'clock will be able to target any hull section, but having a choice of two hull sections to attack will be much more common.
Actually, I think I like this rule better: If you are (or would be) in the firing arc of a fixed mount at 12 o'clock or 6 o'clock, you can only target the front or rear hull respectively. If you are (or would be) in the firing arc of a fixed mount at 3 o'clock or 9 o'clock, you can target any hull section. In between you have to choose between either front/central or rear/central. Diagram looks like this:
https://imgur.com/a/mI8UjsJ
  • A ship in the green zone can only attack the front hull.
  • A ship in the red zone can only attack the rear hull.
  • A ship in the yellow zone can attack any hull segment.
  • A ship in the white zone can attack the front or central hull
  • A ship in the gray zone can attack the central or rear hull.
Michael Thayne is offline   Reply With Quote
Old 04-03-2020, 06:25 PM   #5
Balor Patch
 
Join Date: Apr 2013
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Don't forget that, unlike a water ship, a space ship can roll, letting the whole ship be, in effect, a turret. It can make sense to have one side designed to be the engaged side, with armor and direct fire weapons, and the other side soft.
Balor Patch is offline   Reply With Quote
Old 04-03-2020, 07:22 PM   #6
Michael Thayne
 
Michael Thayne's Avatar
 
Join Date: May 2010
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Balor Patch View Post
Don't forget that, unlike a water ship, a space ship can roll, letting the whole ship be, in effect, a turret. It can make sense to have one side designed to be the engaged side, with armor and direct fire weapons, and the other side soft.
This is true, though GURPS Spaceships isn't really set up to model it.
Michael Thayne is offline   Reply With Quote
Old 04-04-2020, 08:46 AM   #7
Rupert
 
Rupert's Avatar
 
Join Date: Aug 2004
Location: Wellington, NZ
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Michael Thayne View Post
This is true, though GURPS Spaceships isn't really set up to model it.
Yet that's exactly what it assumes - it's why centre section turrets can fire to both sides.
__________________
Rupert Boleyn

"A pessimist is an optimist with a sense of history."
Rupert is offline   Reply With Quote
Old 04-04-2020, 09:36 AM   #8
Michael Thayne
 
Michael Thayne's Avatar
 
Join Date: May 2010
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Rupert View Post
Yet that's exactly what it assumes - it's why centre section turrets can fire to both sides.
There are some problems with the default treatment, though. For one thing, large ships might realistically have trouble executing the necessary roll quickly enough. Another problem is that as written if the central hull has two fixed mounts, they can both fire in the same direction on one turn and in opposite directions on another turn.
Michael Thayne is offline   Reply With Quote
Old 04-04-2020, 10:23 AM   #9
Fred Brackin
 
Join Date: Aug 2007
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Michael Thayne View Post
There are some problems with the default treatment, though. For one thing, large ships might realistically have trouble executing the necessary roll quickly enough. Another problem is that as written if the central hull has two fixed mounts, they can both fire in the same direction on one turn and in opposite directions on another turn.
With just 2 turrets and no arbitrarily large and weird superstructures this should always be true just by rotating the turrets.

Remember that Spaceships "turns" are not what Turns are in general Gurps. A Spaceships "turn" is always at least 20 seconds and 1 minute may be more common.
__________________
Fred Brackin
Fred Brackin is online now   Reply With Quote
Old 04-04-2020, 01:29 PM   #10
Michael Thayne
 
Michael Thayne's Avatar
 
Join Date: May 2010
Default Re: [Spaceships] Rationalizing facing and arcs of fire in tactical combat

Quote:
Originally Posted by Fred Brackin View Post
With just 2 turrets and no arbitrarily large and weird superstructures this should always be true just by rotating the turrets.
I'm not sure which of the two sentences you're referring to. The first sentence is referring to the problem where, say, a ship has turrets on the top and the bottom, and in principle it could use both on a ship initially "below" it by rolling 90, but the roll isn't necessarily going to be instantaneous. In the second sentence I specified fixed mounts, which logically should be on one side of the ship or the other but by RAW that doesn't need to be specified.
Michael Thayne 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 10:32 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2022, vBulletin Solutions, Inc.