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 10-30-2011, 02:30 PM   #1
Obscurus
 
Join Date: Oct 2011
Default Ambiguity in high-speed movement rules?

I'm running a campaign that will require a lot of vehicle combat in crowded urban places, and as a result I'm interested in the rules for making sharp corners. But in the Basic Set pg 395, under the heading "Pushing the envelope", it is unclear what the relation is between the amount the turn radius is reduced by and the skill penalty is. Does anyone have any house rules or know of any supplements?

Thanks in advance,
Obscurus
Obscurus is offline   Reply With Quote
Old 10-30-2011, 04:25 PM   #2
Dinadon
 
Join Date: Aug 2007
Default Re: Ambiguity in high-speed movement rules?

That's because their isn't. The penalty is based purely on how fast you are moving. You make the roll if you want to turn before you've traveled your turning radius, or if you want to make a sharper turn. If you want to do more, you have to attempt more rolls.
Dinadon is offline   Reply With Quote
Old 10-30-2011, 05:05 PM   #3
gilbertocarlos
 
gilbertocarlos's Avatar
 
Join Date: Dec 2009
Location: Caxias do Sul, Brazil
Default Re: Ambiguity in high-speed movement rules?

An high speed car chase in a highway is -2.
If you are in a motorcycle it's easier, probably a straight roll.

If you are with one hand occupied by a pistol, -2 extra.
If you want to make a tight curve in a hurry, I would put at least others -2, more if it is a 120º+.
gilbertocarlos is offline   Reply With Quote
Old 10-30-2011, 05:25 PM   #4
Obscurus
 
Join Date: Oct 2011
Default Re: Ambiguity in high-speed movement rules?

Alright, suppose a vehicle with Move 5 is going at speed 20 (40 mph) and wants to make a left turn (radius 7 yds). Its turn radius at that speed is 40. I can't seem to decypher what the appropriate rolls would be. Would the driver make one roll at -3, or two, or 33(!)?
Obscurus is offline   Reply With Quote
Old 10-30-2011, 05:46 PM   #5
gilbertocarlos
 
gilbertocarlos's Avatar
 
Join Date: Dec 2009
Location: Caxias do Sul, Brazil
Default Re: Ambiguity in high-speed movement rules?

Quote:
Originally Posted by Obscurus View Post
Alright, suppose a vehicle with Move 5 is going at speed 20 (40 mph) and wants to make a left turn (radius 7 yds). Its turn radius at that speed is 40. I can't seem to decypher what the appropriate rolls would be. Would the driver make one roll at -3, or two, or 33(!)?
One roll per risky maneuver, the risk is GM's call.
To see how much you can turn, you take actual speed/acceleration, so, if you're in a TL7 sports car(Acc 5), at 60mph(30y/s), you need (30/5)6y movement to change 60º, 9y to move 90º.

If you're doing this, and passing through cars, you will probably need to roll Driving-2, if you don't have enough room, you will need to either slow down before, or another driving roll to slow down while making the curve.
gilbertocarlos is offline   Reply With Quote
Old 10-30-2011, 06:33 PM   #6
Obscurus
 
Join Date: Oct 2011
Default Re: Ambiguity in high-speed movement rules?

That doesn't really make sense to me. Said TL7 sports car would have the same penalty whether it was trying to make a 1-yard-radius turn or an 89-yard-radius turn. My knowledge of physics indicates that's impossible. I guess I'm going to find/make a house rule.
Obscurus is offline   Reply With Quote
Old 10-30-2011, 06:43 PM   #7
Obscurus
 
Join Date: Oct 2011
Default Re: Ambiguity in high-speed movement rules?

I can't find any house rules, so I'm going to make some of my own. I'll report back when I'm done.
Obscurus is offline   Reply With Quote
Old 10-31-2011, 09:28 AM   #8
weby
 
weby's Avatar
 
Join Date: Oct 2008
Default Re: Ambiguity in high-speed movement rules?

action 2 has great chase rules
weby is offline   Reply With Quote
Old 10-31-2011, 04:08 PM   #9
whswhs
 
Join Date: Jun 2005
Location: Lawrence, KS
Default Re: Ambiguity in high-speed movement rules?

Quote:
Originally Posted by Obscurus View Post
Alright, suppose a vehicle with Move 5 is going at speed 20 (40 mph) and wants to make a left turn (radius 7 yds). Its turn radius at that speed is 40. I can't seem to decypher what the appropriate rolls would be. Would the driver make one roll at -3, or two, or 33(!)?
You have Move 5 and total speed 20. To find the turning radius, you divided 20 by 5, and get 4. Your turning radius is 4 yards.

"Turning radius" means the distance you have to travel before you can turn 60° (that is, change facing by one hex side). So you have to go 4 yards straight ahead; then you turn 60°, and you're facing mostly left but not straight left, because a left turn would be a 90° turn.

At this point we can take two approaches.

1. By the strict RAW, you need to travel 4 yards more before you can change facing again. At that point you can turn up to 60°. But to get a 90° turn you only need 30° more. So you can complete your 90° turn in that second 4 yards, but that's a turning radius of 8 yards, not 7.

If you want a turning radius of 7 yards, you have to make a tighter turn. That requires a control roll at a penalty. The penalty comes out to (turning radius in yards) - 1, or 3. So you have to make a control roll at -3.

1A. Still by the strict rules, you can slow down from Move 20 to Move 15. That gives you a turning radius of 3 yards. So you can now do a 90° turn in two steps, 3 yards for each, total 6 yards.

2. On the other hand, really, it seems unreasonable to require you to take the full 4 yards for a 30° turn, since you just used 4 yards for a 60° turn. So I might allow a variant rule: Your turning radius, 4 yards, is the distance you have to travel to do a 60° turn; so each yard you travel lets you do a 15° turn; so to do a 90° turn you need to travel 90/15 = 6 yards. And Bob's your uncle.

More generally, to make a turn of N°, you need a distance equal to (N/60) x (current speed/Basic Move), in yards.

Bill Stoddard
whswhs is offline   Reply With Quote
Reply

Tags
enhanced move, high-speed movement

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 11:20 PM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2024, vBulletin Solutions, Inc.