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These rules were designed as an abstract vehicle system. Its use in Fudge THS is in fact quite limited because most driving is handled and monitored by AIs, so most of the time characters are not allowed any funny stunts. This system can however be used for other settings...

^ 5.4.1 Rules Principle

Normal vehicle driving, either by manual controls or operated by AI, is not difficult even with a Poor driving skill; any obstacles or delicate situation can be dealt with by slowing down and taking your time. Problems arise when speed comes into the picture: chasing or being chased, running against the clock, etc.

I advise the use of an abstract system for vehicles, without markers or anything, partly because physical representation is cumbersome and slows down the game, partly because moving vehicles on a map and choosing speed & turns requires real tactical skill from the player, which may not necessarily reflect the skill level of the character or its aids (AIs).

The core idea of this abstract system is to determine a Drive Performance each turn, by adding up elements from the vehicle attributes, external condtions, and the level of risk taken by each driver. The higher Drive Performance wins the round and can decide what it will do. The GM can however describe the action and the environment to the players, letting them choose tactical options and risks levels, and interpreting results action-wise. The probability of a Crash is only linked to the level of risk taken by the drivers, but the consequences are higher if the external conditions are difficult.

First of all the GM should determine the objectives of each opponent. A Chase occurs when one opponent tries to run away, and the other tries to catch him. If both opponents run away, there is no Chase; if both opponents want to stop the other car, there is no chase either, they just stop a few meters away. In a Chase, the Catcher usually starts behind the Prey, and usually tries to Close the distance with his Prey in order to Fire weapons (from a gunner, or from a turret, or from a fixed point), or to Ram the Prey, or to Block its way. The Prey usually tries to Break-Off, or to Loose the Catcher, or to Fire back, or even to Ram the catcher if he tries to Block him. All is conditionned by the distance between the Prey and the Catcher.

The Distance is measured in Combat Turns, i.e. 3 seconds. A distance of 1 turn means around 25m if both vehicle have a speed of 30 km/h (20 mph), 40m at 50 km/h (30 mph), 80m at 100 km/h (60 mph), 160m at 200 km/h (120 mph). A chase usually starts with the two vehicles separated by 3 combat turns (around 10 seconds, or 150m in a city...). Combat Turn is also used to position External Elements in the chase, like: "There is a street to the left in 2 combat turns", or "Watch-out, Pedestrian Crossing in 3 combat turns !". When Opponents are separated by one or more Combat Turns, the External Elements are reached at different times by the two opponents: e.g. there is a street to the left in 2 combat turns for the Prey, and the Catcher is 2 combat turns behind the Prey; the Prey will reach the street to the left in 2 combat turns, and the Catcher in 4 combat turns, provided he doesn't Close the distance. Combat Turns also indicates for how long the Line-Of-Sight is broken when the Prey turns into a street; The Catcher must wait as many turns as the distances between him and the Prey (including this turn) before having a clear Line-Of-Sight allowing him to fire.

^ 5.4.2 Vehicle Attributes

Vehicule construction should follow the WVMDS design rules (ITW). You'll find below guidelines to transform WVMDS vehicle attributes into FTHS vehicle attributes.

• Size: Used mainly for determining DDF. Use the Size Conversion Table, and only consider the Body HP.
• Armor: Same kind of Armor Level and PD as for characters. Use the Size Conversion Table and only consider the Body Armor.
• Max Speed (in km/h): is hardly ever used. If Max Speed is greatly different between opponents, the highest can usually do what it wants. In a pure speed contest, straight road, no obstacles, fair conditions, the highest Max Speed always wins, period. However in chase, with turns, etc... comparable Vehicles hardly ever reach their Max Speed, so this is not a major factor.
• Acceleration (Acc): in GURPS, Max Acceleration mesured in km/h/s (or mph/s). Use the following table to determine Acceleration Attribute (additionnal rows: +1 per 0.5 G or 5 km/h or 3 mph):

  Acc (mph/s)	Acc (km/h/s)	Acc (G)	Acceleration Level	Modifier
  1-5	1-9	0.1-0.9	Terrible	-3
  6-8	10-14	1.0-1.4	Poor	-2
  9-11	15-19	1.5-1.9	Mediocre	-1
  12-14	20-24	2.0-2.4	Fair	0
  15-17	25-29	2.5-2.9	Good	+1
  18-21	30-34	3.0-3.4	Great	+2
  22-24	35-39	3.5-3.9	Superb	+3

• Deceleration (Dec): in GURPS, mesured in km/h/s (or mph/s). Use the following table to determine Deceleration Attribute (additionnal rows: +1 per 0.5 G or 5 km/h or 3 mph):

  Dec (mph/s)	Dec (km/h/s)	Dec (G)	Deceleration Level	Modifier
  1-5	1-9	0.1-0.9	Terrible	-3
  6-8	10-14	1.0-1.4	Poor	-2
  9-11	15-19	1.5-1.9	Mediocre	-1
  12-14	20-24	2.0-2.4	Fair	0
  15-17	25-29	2.5-2.9	Good	+1
  18-21	30-34	3.0-3.4	Great	+2
  22-24	35-39	3.5-3.9	Superb	+3

• Maneuver (Man): in GURPS the Maneuver Rating (MR) is used to determine the limit for safe turning, in Gs. Use the following table to determine Maneuver Attribute (additionnal rows: +1 per 0.5 G):

  MR (G)	Maneuver Level	Modifier
  0.25 (0.01-0.35)	Terrible	-3
  0.50 (0.36-0.60)	Poor	-2
  0.75 (0.61-0.85)	Mediocre	-1
  1.00 (0.86-1.15)	Fair	0
  1.50 (1.16-1.65)	Good	+1
  2.00 (1.66-2.15)	Great	+2
  2.50 (2.16-2.65)	Superb	+3

• Stability (Sta): to determine Stability Attribute, use GURPS Stability Rating (SR) and divide it by 2, rounded down. Stability is not used to determine Drive Performance, but rather to minimize effects of Crash.
• Piloting (Pil): a bonus or a malus for the driving aids the driver can benefit from (AIs, Scanners, Radars, etc...).

NB: when a driver voluntary limits its performance below the possibilities of the vehicle, for example for limiting G-Effects on crew/passengers/cargo, recalculate the modifiers according to the maximum acceptable G.

Here are examples of THS Vehicles:

Groundcrafts

Aircrafts

Watercrafts

^ 5.4.3 External Elements

They are thrown at the drivers by the GM, either on a pre-planned basis, or randomly. Their nature and frequency must of course match the setting - there is no Pederstrian Crossing in the middle of the desert. Here is a list of External Elements and their effects.

(*) Red Light: you must also specify the traffic on the crossing road (Light, Medium, Heavy) which is another External Element, adding up Modifier and Attributes

External elements can be cumulated (e.g. a Straight Line, with Medium Traffic, and a Red Light for a Light Traffic crossroad). All the Modifier of all External Elements are added-up ( 0 for Straight Line, -2 for Medium Traffic, -3 for Red Light, -1 for Light Traffic crossroad, total -6). The Attributes specified for each Element show what Car Attributes can be used to add-up to the Drive Performance (e.g. Acc for Straight Line, Dec for Medium Traffic, Man for Red Light, Acc for Light Traffic crossroad, so you can use all 3 attributes Acc, Dec, Man)

Chases can occur between ground and air vehicles: the aircraft may have no External Elements, or can have external elements like high buildings, where crash consequences tend to be more lethal.

For situations with hardly any obstacle (in the desert, in air, water, space...), there is no Element Modifiers. Two type of contest may arise:

• Speed Contest: the chase is usually won by the highest speed each turn, except maybe for the first few turns when vehicles are accelerating, where the vehicle with the highest Acc may have the upper hand.
• Dogfight: vehicles are circling each other, trying to dodge enemy fire and to position themselves for a good shoot. All Vehicle Attributes can be used.

^ 5.4.4 Combat Turns

Turn Phase: for each turn, the GM determines External Elements for each opponents, which determine Elements Modifiers and Car Attributes that can be used, which sum is the basic Drive Performance Modifier. Then, each opponent defines (secretly) the Risk Level he is willing to take, then reveals it. A Driving Roll is then made (Driver Driving skill + Car Piloting Attribute + 4dF), and compared with the Risk Level, which it should at least tie to be successful. No Driving Roll is required if the chosen level is Non-Existent (-4): success is automatic (but Risk Level is -4).

Risk level: each Turn, each drivers simply chooses a level between Non-Existent (-4) and Superb (+3). This defines the minimum roll he must make to avoid Crash, and the resulting modifier he succeeds. If the driver is an integrated AI there may be a maximum Risk Level it's willing to take - could be as low a -4 for a real self-preserving or limited AI !

Driving Skill: The driver of each vehicle uses the appropriate Driving Skill to determine the success of his drive. The driver can very well be an integrated AI controlling the car. If the driver is Human he adds to his Driving Skill the Car Piloting Attribute (see below).

If the Driving Roll is successfull, then the Driving Performance of this turn is equal to:

Note: the driving roll itself is not taken into account in the Driving Performance, you just have to be successful.

If both driving roll for each opponent were successful, then the winner is the one with the highest Driving Performance. A tie means no one wins, off to next turn. If one of the opponent only succeed its roll, he automatically wins, the loser's Driving Performance is 0, and the loser Crashes. If both opponent fail their rolls, no-one wins, and both Crash.

If the winner is the Catcher, he can do one of the following:

• If distance is greater or equal to one combat turn, he may reduce the distance by one combat turn. If by doing so he could "jump" an External Element (a turn, a red light), the GM will add this External Element to his next turn.
• If the distance is equal to zero, he may Ram the Prey. The difference between the two Driving Rolls determines the Ram damage (full damage for the Prey, half damage for the Catcher).
• If the distance is equal to zero since 2 turns or more, he may Block the Prey. In return the Prey may Ram the Catcher. If not the Prey must stop its car.
• If the Line-Of-Sight is not blocked (no turns), and if the distance in combat turns is not greater than 0 for Heavy Traffic, 1 for Medium Traffic and 2 for Light Traffic, the Catcher may Fire one weapon (Turret, Hand, or Fixed, at -1 for cumulated tasks).

If the winner is the Prey, he can do one of the following:

• He may increase the distance by one combat turn
• If the distance if greater than 3 turns and if the catcher has no way to track the Prey (scanner, radar, tracking device, satellite,...), he may attempt to Lose the Catcher. This requires a Driving Roll, modified by the Car Piloting, against a difficulty of Superb + Catcher Perception - Distance in combat turn + External Element Modifiers. If he wins, the Chase if over, the Catcher has lost its Prey. The GM may require additionnal rolls if the Prey doesn't drive away and if the Catcher seeks for it.
• If the distance is equal to zero since 2 turns or more, he may Ram the Catcher. The difference between the two Driving Rolls determines the Ram damage (full damage for the Catcher, half damage for the Prey).
• If the Line-Of-Sight is not blocked (no turns), and if the distance in combat turns is not greater than 0 for Heavy Traffic, 1 for Medium Traffic and 2 for Light Traffic, the Prey may Fire one Turret or Hand weapon (at -1 for cumulated tasks).

At every turn, for both the Catcher and the Prey, a Gunner not driving the vehicle may fire at the opponent if the Line-Of-Sight is not blocked (no turns), and if the distance in combat turns is not greater than 0 for Heavy Traffic, 1 for Medium Traffic and 2 for Light Traffic.

Shooting: Difficulty is Fair for distance 0, Good for distance 1, Great for 2, etc... Add 2 levels of difficulty for a Called Shot to a specific system. Reduce by 1 level if the targeted vehicule is significantly larger than the shooter's (size +3 or more). Targeting systems may reduce the difficulty by 1 or more levels.

Crash: If the Driving Roll is failed, the vehicule Crashes. The Crash Level is the Failure Margin of the Driving Roll, reduced by the vehicle's Stability Attribute (+2dF optionnally if you want to add some spice). Check the Crash Table below:

Don't forget also to check the Crash Level against the External Elements table to see additionnal effects:

• Crash with a Sidewall: 1dF+1 Damage on the Damage table (not modified by DDF) (Nb: a Sidewall may very well be a parked car, or a garbage can,...)
• Crash with a Vehicle: take (1dFx3+1dF+5) Damage on the Damage table (not modified by DDF)
• Crash with a Pedestrian: No Damage, but bad for your karma

Of course, Risky Driving, Crash with a Sidewall can leads you to be fined, Crash with a Car or a Pedestrian leads you to prison if you kill someone, and Use of Weapons is strictly regulated...

There is a specific Crash table for Air Vehicles:

For Air Vehicles, Crash against External Elements and Ramming tend to be lethal.

^ 5.4.5 Vehicle Damage

Vehicle Damage is determined much like character damage (Penetration, Damage). Check the following Damage Table:

Breach: for sealed vehicles.

Repair: Repair Roll indicates the required Mechanic roll required, with base time equal to Base Repair Time x Size (NB: you can have more than one mechanic working on it for accelerated repair). Reparing a damaged system requires a Mechanic or Electronic Fair roll, base time (Size/2) man-hours. Reparing a destroyed system requires a Mechanic or Electronic Good roll, base time base time (Size*2) man-hours. (...This needs some adjustment...)

System Table: Roll 2 dFs, one after the other, and check the following table:

If a rolled system is unavailable or destroyed, take the next line on the table.

^ 5.4.6 Detailed Example

Jon is chased by Mad.

• Jon (Good Driver) drives a car with a Good Acceleration (+1), a Good Deceleration (+1), a Good Maneuver (+1), a Good Stability (+1) and Fair Piloting (+0).
• Mad (Fair Driver) drives a car with a Great Acceleration (+2), a Mediocre Deceleration (-1), a Fair Maneuver (+0), a Fair Stability (+0) and Good Piloting (+1).

Turn 1: The GM decides that Mad is 3 Turns behind Jon when Jon notices him. They are both on a Straight street, with Medium Traffic and no traffic light. Jon asks to the GM if there is an exit to some narrow neighborhood nearby. The GM says he can make a Sharp Turn left in 3 turns, after a Red Light with a Light Traffic in 2 turns.

Elements determine the Modifier (0,-2 = -2 for both) and the allowed Attributes (Acceleration and Deceleration). Jon's Mods are -2 (Elements) +1 (Acc) +1 (Dec), so +0. Mad's Mods are -2 (Elements) +2 (Acc) -1 (Dec), so -1. Jon decides to take a Poor Risk (-2), and Mad a Fair Risk (0). Jon's skill is Good (+1) + Fair Piloting (+0), that's Good (+1) versus Poor Risk (-2), he wins on a -3 or more - and he does, easily. Mad's skill is Fair (0) + Good Piloting (+1), that's Good (+1) versus Fair Risk (0), he needs -1 or more - and he's successful.

Jon's Risk was Poor (-2), plus his mods (+0), give him a Poor (-2) Driving Performance (no risk, no glory). Mad's Risk was Fair (0), plus his mods (-1), give him a Mediocre (-1) Driving Performance. Mad wins, and decides to close the distance. Now he's 2 turns behind Jon. Jon starts to understand that Mad is out for a kill... He steps on the gas.

Turn 2: Still both on a Straight street, with Medium Traffic and no traffic light. The Red Light with a Light Traffic is 1 turn ahead, the Sharp Turn 2 ahead.

Mods are the same (+0 for Jon, -1 for Mad). Jon decides to take a Fair Risk (0), and Mad a Fair Risk also (0). Jon's level is Good (+1) versus Fair Risk (0), he wins on a -1 or more - and he does. Mad's level is Good (+1) versus Fair Risk (0), he needs -1 or more - but he rolls -2 and misses by 1 !!.

Jon automatically wins and increase the distance (3 turns). Mad checks the Crash table, a negative margin of 1, not modified by Stability (+0), that's a Medium Skidding. Checking the Element Table, he would need 2 for crashing a Car. He just dodged one truck.

Turn 3: Still both on a Straight street, with Medium Traffic, but with a Red Light and Light Crossing Traffic for Jon... the Sharp Turn is 1 turn ahead.

Mod's still -1 for Mad, but Jon is at : 0 (Straight line) -2 (Medium traffic) -2 (Red Light) -1 (Light Crossing Traffic), that's -5 for elements !... On the other hand he may use his Acc (Straight line), Dec (Medium Traffic) and Man (Red Light), that's +1 +1 +1 = +3. Total Mods: -2... Jon decides to take a Fair Risk (0), and Mad a Fair Risk also (0). Jon's level is Good (+1) versus Fair Risk (0), he wins on a -1 or more - but rolls -2 and misses by 1 !!! . Mad's level is Good (+1) versus Fair Risk (0), he needs -1 or more - and he succeeds.

Mad automatically wins and closes in (2 turns). Jon checks the Crash table, a negative margin of 1, modified by Good Stability (+1), Crash Level 0, that's a Skidding with no consequence. Checking the Element Table, he would need 2 for crashing a Car (Medium Traffic), or 2 to crash a crossing car (Light Traffic, -1 for crossing). He just dodged one car.

Turn 4: Mad is on the Straight street, with Medium Traffic, the Red Light is 1 turn ahead of him. Jon can take the Sharp Turn into a Narrow Street with Light Traffic if he wants - and he does.

Mod's still -1 for Mad, but Jon is at : -2 (Sharp Turn) -1 (Narrow Street) -1 (Light traffic), that's -4 for elements. On the other hand he may use his Acc (Light Traffic) and Man (Narrow Street, Sharp Turn), that's +1 +1 = +2. Total Mods: -2... Jon decides to take a Poor Risk (-2), and Mad still a Fair Risk (0). Jon's level is Good (+1) versus Poor Risk (-2), he wins on a -3 or more - and he does . Mad's level is Good (+1) versus Fair Risk (0), he needs -1 or more - and he succeeds also.

Jon's Risk was Poor (-2), plus his mods (-4), give him a -6 Driving Performance... Mad's Risk was Fair (0), plus his mods (-1), give him a Mediocre (-1) Driving Performance. Mad wins, and decides to close the distance. Now he's now 1 turn behind Jon. Note that he would have to negociate both the Red Light and the Sharp Turn next turn to keep on Jon's toes (the closing doesn't prevent him from dealing with Elements). However the GM suddenly decides that the light turned green, so there is no crossing !!! Jon grinds his teeth.

Turn 5: Mad is negociating the Sharp Turn into a Narrow Street with Light Traffic, and Jon is in a Straight Narrow Street, racing ahead.

Elements are -4 for Mad and he may use his Acc (Light Traffic) and Man (Sharp Turn), that's +2 +0 = +2; his final mod is -2. Jon is at : -1 (Narrow Street) -1 (Light traffic), that's -2 for elements. On the other hand he may use his Acc (Light Traffic) and Man (Narrow Street), that's +1 +1 = +2. Total Mods: 0. Jon decides to take a Poor Risk (-2), and Mad still a Fair Risk (0). Jon's level is Good (+1) versus Poor Risk (-2), he wins on a -3 or more - and he does . Mad's level is Good (+1) versus Fair Risk (0), he needs -1 or more - but he rolls -3 and fails by 2 !

Jon automatically wins and increase the distance (2 turns). Mad checks the Crash table, a negative margin of 2, not modified by Fair Stability (+0), Crash Level 2, that's a Major Skidding with -1 to all actions this turn and to Piloting next turn... Checking the Element Table, the Sharp Turn (2) makes him hit the sidewall of the street, he takes 1dF+1 damage. Damn !!!

Next turns: Jon is in narrow streets, where his Maneuver rating can give him an Edge, if he manages to find Medium Traffic and Turns to prevent Mad from using is Great Acceleration...

The material presented here is my original creation, intended for use with the GURPS system from Steve Jackson Games. This material is not official and is not endorsed by Steve Jackson Games.

GURPS is a registered trademark of Steve Jackson Games, and the art here is copyrighted by Steve Jackson Games. All rights are reserved by SJ Games. This material is used here in accordance with the SJ Games online policy.

ABOUT FUDGE
FUDGE is a role-playing game written by Steffan O'Sullivan, with extensive input from the Usenet community of rec.games.design. The basic rules of FUDGE are available on the internet via anonymous ftp at ftp.csua.berkeley.edu, and in book form or on disk from Grey Ghost Games, P.O. Box 838, Randolph, MA 02368. They may be used with any gaming genre. While an individual work derived from FUDGE may specify certain attributes and skills, many more are possible with FUDGE. Every Game Master using FUDGE is encouraged to add or ignore any character Traits. Anyone who wishes to distribute such material for free may do so - merely include this ABOUT FUDGE notice and disclaimer (complete with FUDGE copyright notice). If you wish to charge a fee for such material, other than as an article in a magazine or other periodical, you must first obtain a royalty-free license from the author of FUDGE, Steffan O'Sullivan, P.O. Box 465, Plymouth, NH 03264.

DISCLAIMER
The following materials based on FUDGE, entitled Fudge TransHuman Space, are created and made available by Loïc Prot, and are not authorized or endorsed in any way by Steffan O'Sullivan or any publisher of other FUDGE materials. Neither Steffan O'Sullivan or any publisher of other FUDGE material is in any way responsible for the content of these materials. Original FUDGE materials (c) Copyright 1992-1995 Steffan O'Sullivan, All Rights Reserved.