________________________________________ GURPS Vehicles 2nd Edition Additions MA Lloyd (malloy00@io.com) 9 August 1998 Modifications and Additions to Chapter 14: Combat ________________________________________ p175 Gunner Specializations. Add Mechanical Artillery, Mechanical Machine Gun and Releasing Bombs. Split Guided Missile into Operator Guided Missile and Homing Missile. p177 Vehicular Combat Modifiers. Windows should use the standard cover rules not a flat penalty. p177*Vehicular Combat Modifiers. Neural Interfaces. Drop (minimum skill 12). p179*Damage Effects. Waterline Damage. The reference is to Combat, not Vehicle Action. p179*Indirect Fire. At end of the first paragraph, change "increases the weapon's maximum range" to "multiplies Max range by 2.5 (5 if a missile)." p180*Indirect Fire (Continued). The modifier for "Relying on observer to find target" is 0**, not -5**. Under **, change "penalty is reduced" to "this is increased" and "increased by the amount it fails by" to "decreased by the amount it fails by". Under Correcting Fire, change the last sentence to read "To correct fire, roll again, but at a +4 bonus for the first shot or +8 for the second, with an added +2 for each subsequent shot at the same target; however, the total bonus for correcting fire cannot exceed the weapon's Accuracy." p181*Water Speed. The cube root table is on p138. p182*Component Damage Table. Result 7-Equipment also includes items from the Instruments and Electronics chapter. p183*Components and Damage. In the third paragraph following the Component DR Table, the first sentence should read "A fuel tank checks for fire (see p. 184) if damage from a single damage roll exceeds 10% its current hit points; if reduced to 0 hit points, it bursts and all fuel is immediately lost." The next sentence begins "Also" not "Instead". p184*Fire and Explosion. In the first paragraph of Fuel Tanks, "at least 5%" should be "at least 10%". p184*Fire and Explosion. Roll for explosion only every 10 seconds, not every second. p186 Weapon Ranges Underwater. *Rainbow* lasers are 1/10, other lasers are 1/50, and x-ray or gamma ray lasers are 1/1000. p186 Flooding-Taking on Water. Alter the mechanics of compartments, instead of 1 roll after 1 minute use 'For every 20% of the vessel's flotation flooded (10% if heavily compartmentalized, 5% if totally compartmentalized) roll 2d. On an 8 or less the flooding stops.' p186 Antimatter and Nuclear Power Plant Explosions. A gram of antimatter yields the equivalent of a 45 kT nuclear blast. Treat antimatter plant explosions as (kW-yrs/150) kiloton nuclear explosions. Double damage at TL11, the less efficient plants store more antimatter. p187 Escaping Sinking Vehicles. The danger radius makes no sense. Use square root of (vehicle surface area/10). p190 Bursting Class. WP. White phosphorous isn't this deadly, use 1d-2 per turn after the first. It also does not burn underwater, but since it self ignites in air immersion in water only puts it out temporarily. p190 Prismatic Smoke. Less effective materials that form clouds of colored aerosols or easily ionized gases are available as early as the invention of lasers. Assume these have double cost, last half as long and only halve laser damage for every hex penetrated. p191 HEAT. Rather than 1/6 damage, use the normal KE damage for the gun (i.e. undetonated HEAT acts like solid shot) p192 Guided Missiles. 3rd sentence. 'control one operator guided missile at a time' p192 Wire-,TV-, and Communicator-Guided Missiles. Rename Operator Guided Missiles (compare p116) p192 SICM. The target allocation system implies far too much communications between the bomblets. Instead assume 25% miss and become mines, and assign each of the rest a target randomly - if they all go for the same target that's just bad luck. p193*Homing Missiles. Passive Electromagnetic Homing (PEH) can be used as OH, IIRH, ARM, or PRH. All four options can be tried for lock-on. p193*If an SICM attack missed, it already exploded and can't become a mine. p194 Launching Homing Missiles. Missiles past endurance usually crash, not self destruct. p194 Starshell. Flares are visible to 0.2xBxB miles, or the horizon. p194 Napalm. Napalm does require oxygen to burn, the ingredient list (p107) contains no oxidizer and the igniter depends on air entering the case! p195*Using Inertial Guidance (IG) Missiles. Paragraph 3 should begin "Once launched", not "One launched". In the next sentence "use its skill" should be "use the Gunner's skill". p195 Tangler. Vehicles can also be trapped. Treat them as having an ST of 80 x (motive power - loaded weight in tons). If ST is more than 40 greater than the tangler strands, ignore them. p197 Detecting and Shooting at Missiles. Point defenses can also fire at shells. Compute the size modifier from the VPS, speed is equal to 800 yps * KE DAM/Bore (modifiers to KE DAM for type of shell do apply). Shells are tougher than missiles (50 hp to actually penetrate one) but it may be easier to deflect (0.05 x WPS hp will do that). p197 Bus Missiles. one turn -> shortly Compare p117. p197*Exotic Missile Abilities. Evasion. Replace the first sentence with "Any TL8+ brilliant missile can be programmed with an evasive course; this halves effective speed and thus range." _________________________________________ Combat p181a Orbital Strikes _________________________________________ Vehicles in orbit can fire at a planetary surface. This is normally indirect fire (p179) though if the vehicle can detect targets at the surface it can use direct fire beam weapons. Kinetic Weapons Missiles or gunshells fired from orbit require a considerably different targeting procedure (apply familiarity penalties to Gunner skill and require specialized versions of any software aids). An orbital strike requires 10 minutes to fall from low orbit to the target. Resolve it as an indirect fire or terminal homing attack as appropriate, but because of the velocity difference, treat it as an attack from 10,000 yards up with a speed of 10,000 (allow only 1 turn to lock on, and recompute KE damage for missiles, for guns multiply KE damage by 10). Beam Weapons Use the normal beam rules. If the world has an atmosphere remember the difference between atmospheric and vacuum range. ________________________________________ Combat p186a Energy Bank Explosions ________________________________________ When an energy bank is destroyed the energy content does not simply vanish. A battery releases the energy in the form of active chemicals (treat as splashing the area in acid) but in most cases it will be in the form of hot gases and/or fast moving shrapnel equivalent to a 6d x (kWs/1000) explosion. ________________________________________ Combat p190a CHEM Rounds ________________________________________ Blinding Gas (TL8): an early selective nerve gas. Exposure requires an HT-3 roll every turn to resist, once affected vision fades at -1 per 6 seconds up to -10 (totally blind). After 10 minutes, roll vs. HT each minute to recover 1 point, on a critical failure any remaining penalty is permanent damage. Cost is $10 per dose. This is a humane alternative to mustard or other corrosives, the 'unprotected skin' damage they inflict applies to the eyes as well, any turn of exposure that inflicts 2 or more points of injury should be treated as a crippling injury to the eyes (pB127). Hallucinogen (TL7): Exposure requires an HT+3 roll every 10 turns to resist. A failure causes the victim to suffer visions and bizarre sensory distortions lasting 30-HT minutes. This is usually incapacitating, but victims with Lucid Dreaming skill can remain functional by making rolls every 10 seconds. On a critical failure of the HT roll the hallucinogen causes some sort of insane behavior - often berserk bloodlust - or a fatal reaction (GM's option). Cost is $5 per dose. Hallucinogens are lousy chemical weapons, but popular in fiction. Nerve Gas (TL6): I prefer 'Exposure to nerve gas immediately inflicts 1d+1 fatigue. Five minutes later the victim loses 2d HT, and if the exposure was more than an whiff (make an HT roll if it isn't obvious) must roll against HT 1/4, 1/2, 1, 2, 6 and 12 hours later, suffering another 1d HT per failed roll. If the damage ever takes the victim to -HT, his breathing is paralyzed for 6d hours (though he dies of suffocation much sooner without medical support). Paralysis Gas (TL9): a contact agent, each turn of contact roll against HT-3, on a failure the victim cannot move that turn, on a failure by 3 or more, or a critical failure, he cannot move for (30-HT) minutes and thereafter must roll each minute to recover. Paralyzed victims are conscious, but unable to take physical actions. Cost is $10 per dose. Riot Gas (TL8): an incapacitating gas often used for crowd control. Anyone in the cloud without a gas mask or sealed suit must roll each second at HT-4 or become violently sick. On a success they are simply at -4 to all actions. Sick victims are effectively stunned until they leave the cloud, and for 20-HT minutes after. Cost is $2 per dose. ________________________________________ Combat p192a Guided Missiles _________________________________________ I'd change the mechanisms for two of these. The first section becomes Operator Guided -- roll against Gunner(OG Missile)+4 on launch, and each turn (early TL7) or every 5th turn (later) of flight to keep the missile on target. This includes TVG missiles, the weapons that don't require operator rolls to maintain targeting are Optical Homing, not TVG. Cut the roll to recover control, it is simpler to give a bonus to all rolls and call any failure an unrecoverable loss of control. The other change is Inertial Guidance -- the missile flies to a preset location. To launch, roll against Gunner(Rockets)+4, if successful the missile automatically hits the programmed coordinates. Whether the desired target is located there depends on the Cartography, Navigation or Forward Observer rolls made to determine them. Use the Indirect Fire rules (p179). ________________________________________ Combat p196a Unguided Torpedos _________________________________________ The rules for this are extremely obscure. I think the best approach is to treat this as indirect fire, using Gunner (Torpedo) for to hit rolls, and optionally instead of Forward Observer skill. If the target detects an incoming torpedo allow it a Dodge roll.