Guess always thought of numbers listed under vehicle acceleration as decrease/increase in speed per turn. In 4th its described as walk/run speed of vehicle. Anyone clarify that? What about increasing Acceleration as per Arsenal, which number to use?

I've always ruled that acceleration throws off your aim, but not maintaining constant speed (I believe there is already a "In moving Vehicle" penalty). So for the "a"/"b" format, you can accelerate at "a" with no penalty from acceleration, you can accelerate at "b" without rolling dice. You can make your vehicle test and attempt to accelerate past "b". Until you hit the speed for your vehicle. Also note you should only be able to accelerate once per combat turn.

That's how I've done it.

Oos. What DireRadiant said.

It's walk/Run, which determines whether you apply the walking or running modifiers for the occupants. Take a look at the difference in combat modifiers for defence and offence between walking and running.

Yeah, but walk/run when in reference to metahumans is top end speed. For vehicles acceleration is written in walk/run format, but its not their top end speed.

Non-anthroform vehicle movement is a hell of a lot smoother than a metahuman walk.

I've always looked at it as: Full Acceleration / Hard Breaking

I've never really thought of stopping speeds... Would be good information, was this provided in 3rd? Otherwise I don't know how you would come to this from whats provided in the BBB.

i see it as them being walk/run for ease of use in non-vehicle combat. and when in vehicle combat one only really need to care about the top speed and run speeds.

as in, the run speed is how much you can modify a vehicles speed by (not that it have any effect on the vehicle combat rules, rules that beyond that and the missing rigger pool have a interesting likeness to the rules used in SR3 that was proclaimed as troublesome by just about anyone) and the top speed being just that...

so, if you want to calculate how fast a vehicle will get up to speed with a average driver behind the controls, just divide top speed by running speed and have fun. but if you got a rigger or anyone else thats pulling all the tricks to get the most out of the vehicle, use the sprint rules.

Page 159 BBB -
Acceleration
Vehicles have an Acceleration rating that determine their
movement rates. Th e number to the left of the slash is a vehicle’s
Walking rate in meters per turn. Th e number to the right is its
Running rate.
A drive or drone can attempt to move a greater distance by
making a Vehicle Test (see below). Each hit on the test adds 5
meters to the vehicle’s movement rate.

Bah, that's the wussy way to do it.

Just hit something that won't move. There, stopped. Easy enough.

Just don't be like Niko Bellic and forget to wear your seatbelt.

funny thing, the more i look at the vehicle rules, the more useless that top speed entry becomes

Yeah, its really nothing more than a number to say my car goes this fast. Street races is about the only place to use it, since in "Chase Combat" the Bust-a-Move doll has the exact same chance to loose a tail as the Eurocar Westwind. Or better yet the Westwind has the same chance to loose the Bust-A-Move as the Bust-A-Move has at loosing the Westwind.

It's easy for the Bust-A-Move to lose the Westwind. Just have it drop to the ground, Westwind drives over it, and then run to an alleyway. By the time the Westwind has curned a few corners, poof, no Bust-A-Move!

I'll admit to being rather fuzzy on the vehicle rules but I thought that the speed rating was the maximum reasonable velocity for the vehicle. After it was exceeded the GM was supposed to start adding penalties to any test that involved the maneuver rating. A vehicle has to be designed to be stable at high speeds and this is reflected in the speed ratings for the various different types of vehicles.

p. 158

"Speed
Speed is the reasonable high-end maximum velocity of
the vehicle. Drivers can accelerate past this, but start suff ering
real diffi culties in trying to get their vehicle to go faster and
still maintain control. Th e gamemaster should apply modifi ers
as she feels appropriate.
Speed is expressed in meters per Combat Turn."

The Eurocar Westwind has +3 handling. This adds 3 dice to the test to determine initial distance range, and adds to subsequent tests to break the engagement. Thsi makes this vehicle harder to get into good engagement range, and hard to keep in good engagement range.

Cyborgs, weirdly enough, use the top speed of their shell as their running rate, overriding the walk/run aspect of accelleration.

I'd run it like this: accel is how much you can add to your current speed, until top speed. If you add under the walk rate, you are treated as walking. If you add more, then you are treated as running. I'd also rule that this covers deccel as well. I'm not sure how RAW that is, it's my best interpretation.

when dealing with vehicles in person scale combat, I'd limit it to walk/run as listed in accell, and point out that any faster and your vehicle cannot maneuveur appropriately to the combat anymore.

Honestly, the vehicle rules require a lot of common sense anyway, they aren't very detailed. Numbers are only supplied where they must be, anything else is treated as a special effect. For a game where one of the archetypes is a cybernetic wheelman, I'm not sure how appropriate that is, but this isn't a mecha game either, so we don't need hella detailed vehicle rules.

Yeah. One of the sammies I game with bought a Morgan and was chortling that he could outrun my rigger's hovercraft. I pointed out that statistically I will outrun him thanks to my bigger dice pool and that only Rigger Jesus can make the performance vehicles hit their top speed, since it can require 20+ successes.

We're toying with using the old (SR2? SR3?) mechanic of Successes x Acceleration to go faster. The GM's leery since he doesn't want me getting my drones out of/into range any faster than I already can. I can't blame him so I'm not pushing the matter.

Is Rigger Jesus like a buddy jesus but who sways back and forth on your dashboard like a hula girl?

3rd sorta smoothed it over by saying that you decelerate at the same rate you accelerate at, but that you had to make a crash test if you decelerated more than 4x Acceleration at once.

~J

I treat accel as something like an extended test, each success adding 5 mts/turn over running speed, which you may continue improving pass after pass. It sure beats the 2mts per hit of a running sam athletics test.

Cheers

Max

It's a significant change mechanically between editions, and part of the abstraction of combat in SR4. The walk/run acceleration rates really have very little effect other then combat mods for actions involving vehicles. Otherwise the mechanics for trailing, escaping, catching, maintaining range, ramming, all involve vehicle tests with the vehicle handling test the most significant factor from the vehicle, the other factors are from the vehicle handlers skill pool.

What you can consider is that most vehicles aren't really driven and handled at their top speeds, and the typical engagement speeds will be in approximately similar for a given class of vehicles. Therefore the vehicles handling and driver skill are more important overall in those conditions. However, if a vehicles top speed can be reached, which also is done faster with better handling and skill, the GM can always easily rule that a vehicle achieving top speed that outclasses an opponent can escape.