New rules for Force Fields: Anyone who has ever tried to construct any of the Ultra-Tech force fields with Vehicles II (or for that matter, with Vehicles I) will have discovered that it doesn't work particularly well. In addition, unlike Space (in which force screens are mostly for _large_ vehicles), it is generally most useful to put screens on small vehicles. These rules attempt to correct these flaws; in addition, they try to make force fields behave like something distinct from 'armor which costs power', which is what they are now. In addition, some effort is made to generate stats which are consistent with Space and Ultra-Tech (somewhat difficult, as the two aren't very consistent with one another). To design a screen, choose a 'screen rating' and any relevant options. Multiply power, weight, and cost by screen rating; to determine DR, use the _lesser_ of SR/diameter and sqrt(SR), multiplied by the DR modifier of the screen type; assume the necessary diameter is equal to that distance which gives a size modifier equal to the size modifier of the vehicle. No screen may be designed with a diameter less than the minimum listed, or with a SR lower than its diameter. For reference, 'minimum diameter' was mainly chosen to be consistent with Space's claim that screens only appear on ships at TL 11, tanks at TL 12, personal at TL 13. Otherwise, backpack screens (compact, DR 200*2 yards, $4k, 15 lb with D cell) would probably appear at TL 12. *Options list: TL option weight power cost DR MinD 11 deflector 4 10 500 .25 1 12 deflector 2 10 250 .25 1 13 deflector 1 10 125 .25 1 11 PD 7 *2 *2 *2 *1.5 1 11 PD 8 *5 *5 *5 *2 1 12 PD 9 *10 *10 *10 *3 1 13 PD 10 *20 *20 *20 *5 1 14 PD 11 *50 *50 *50 *7 1 15 PD 12 *100 *100 *100 *10 1 12 Active Deflector *2 - *4 - - 13 Active Reflector *4 - *10 - - 11 basic screen 10 5 1000 100 50 12 basic screen 5 5 500 100 10 13 basic screen 2 5 200 100 2 14 basic screen 1 5 100 100 1 15 basic screen .5 5 50 100 1 11 Overload: explosive /2 - /2 - - 12 Overload: -1 TL - - /2 - - 13 Overload: -2 TL - - /4 - - 12 compact *.5 - *2 - - 13 ultra-compact *.25 - *5 - - ------------------------------------------------------------------------- 11 Walk-through - - - - - 11 Rigid Barrier - - - - - 11 Flexible Barrier - - - - - ------------------------------------------------------------------------- 11 Spheroidal - - - - - 11 Plane *.5 - *.5 - - 11 External Node *.5 - *.5 - - 11 Internal Node *.8 - *.8 - - 12 Grid - - - - - 12 Contour-following - - +50% - - 12 Simple-shape - - +100% - - 13 Complex-Shape - - +200% - - 13 Manipulator *2 *2 +100% - - 13 Cutting - - +100% - - ------------------------------------------------------------------------- 11 Permeable - - - - - 11 Semi-Permeable - - - - - 11 Impermeable - - - - - 12 Filter - - +100% - - ------------------------------------------------------------------------- 11 Transparent - - - - - 11 Double-Obscuring: 1-10 - - - - - 12 Obscuring: X (X = SR/D) - - +100% - - ------------------------------------------------------------------------- 11 Velocity-limited - - - *1.5 - 11 Energy Screen - - - *2 - 11 Kinetic Screen - - - *1.5 - 11 Fragile - - - *1.2 - 12 Unbreaking - - - *.5 - 12 Hardened: 2 - - - *.8 - 13 Hardened: 5 - - - *.6 - 14 Hardened: 10 - - - *.5 - 11 Proportional: 50% - - - *2 - 11 Proportional: 80% - - - *1.5 - 11 Proportional: 90% - - - *1.2 - 12 Energy Absorbing - *.01 - *.8 - 11 Dual - - - *2 - 11 Slow Flicker - - - *.9 - 12 Fast Flicker - - - *.75 - 12 Portal - - - *.75 - 11 Fixed-Tuned - - - *.9 - 12 Variable-Tuned - - - *.75 - *Deflector*: multiply DR by diameter; multiply all other stats by the square of the desired diameter. *PD X*: stats are for PD 6; multiply to get higher PDs. *Active Deflector*: the screen is usable for an active block; you get one block at half skill, or any number of blocks at 1/3 skill. The 'deflector screen' skill is P/E. *Active Reflector*: the screen may be used to reflect attacks back on the attacker; only applies to blocked attacks; this includes the 'active deflector' option. Roll to hit against your deflector shield skill, with Acc equal to PD -- aiming only works if you know beforehand that someone is going to shoot at you (and aim at them), or if they're hosing you with automatic weapons fire. You are limited to reflecting (deflector DR*12) or (force screen DR/5) dice. *Basic Screen*: multiply all stats except DR by screen rating; multiply DR by the lesser of (SR/diameter) and sqrt(SR). *Basic Screen, TL 11*: when overloaded, screen suffers HT*10 damage. *Basic Screen, TL 12*: when overloaded, screen suffers HT damage. *Basic Screen, TL 13*: when overloaded, screen suffers 1d*10% damage. *Basic Screen, TL 14*: when overloaded, screen shuts down, reboot in 5 minutes. *Basic Screen, TL 15*: when overloaded, screen ceases to protect until it has lost an energy level. *Overload: explosive*: when overloaded, screen detonates for 6d*SR. *Overload: -1 TL*: use overload behavior of previous TL screen. *Overload: -2 TL*: use overload behavior of screen two TLs previous. *Compact*: includes overload: -1 TL. *Ultra-Compact*: includes Overload: -2 TL. *Walk-Through*: this screen can be passed through at a slow walk. Automatically true of velocity-limited screens. *Rigid Barrier*: this screen cannot be passed through, and acts as a wall; this is likely to be extremely inconvenient on a planet. Depending on the tech, if anything intercepts the screen when it is turned on it will either be sliced through (does 6d*DR/20 cutting, per hex) or simply leaves a hole in the screen. *Nonrigid Barrier*: this screen cannot be passed through, but rather than acting as a wall, it acts as a zone which pushes objects away. Roughly equally annoying on planets. *Spheroidal*: the generator protects a spherical region. *Plane*: the generator creates a flat ward at a distance no greater than the effective diameter of the screen, and no larger than the effective diameter of the screen. *Grid*: the generator creates a screen which follows the outlines of a solid grid; the grid is flexible, and counts as a surface feature: .1 lb and $10 per square foot. *External Node*: the field forms between several 'nodes' (this may be combined with the 'plane' option. The nodes themselves are not protected by the field. This is typically used for doors. *Internal Node*: as above, but the field does protect the nodes. Protecting an entire vehicle requires a minimum of 4 nodes. *Contour-following*: the field which is created will wrap itself around objects within the field; standard for personal shields. Likely to be extremely irritating unless it is a walk-through or manipulator screen. *Simple-Shape*: the field can take a variety of simple shapes. *Complex-Shape*: the field can be sculpted into more or less any shape which is topologically equivalent to a sphere. *Manipulator*: the screen is actually usable to manipulate things -- this is mostly useful with grid, shaped or contour-following screens. The screen has a ST equal to DR/10 per hex, and can apply ST across a number of hexes equal to its diameter. *Cutting*: the screen can manifest cutting surfaces, doing swing/cut(5) damage; must already have the 'manipulator' option. *Permeable*: the screen permits gases through. *Semi-Permeable*: the screen slows passage of gases; it adds +6 to resist atmospheric effects for the first second, losing one bonus per doubling in time (and thus dropping to zero after a minute); this includes both pressure drops and airborn toxins. *Impermeable*: gases do not pass through the shield; treat as sealed. If the shield is to be maintained for a significant length of time, life support is required. *Filter*: the shield acts as an NBC filter. *Transparent*: the shield does not affect sensors *Double-Obscuring*: subtracts 1-10 from sensor rolls through the shield, in either direction; if -10, simply stops sensors. *Obscuring*: subtracts (SR/diameter) from sensor rolls through the shield; does not affect use of sensors from inside. *Velocity-limited*: see description in UT 2 *Energy Screen*: like velocity-limited, but more so. Full effect against photons, half effect against particle beams, no effect against other weapons. *Kinetic Screen*: the reverse of an energy screen. No effect vs photons, half effect vs particle beams, full effect vs other attacks. *Fragile*: the screen shatters if it takes more than its DR in one hit. *Unbreaking*: the screen does not overload. UT2 calls this 'rigid'. *Hardened*: if armor divisor is less than the level of hardening, ignore the armor divisor; otherwise, multiply DR by hardening before applying the armor divisor. *Proportional*: the screen only stops part of the damage of an attack. Other armor beneath can stop the rest. *Energy Absorbing*: an energy absorbing screen _generates_ power, at least while it is discharging. Assume it generates DR^2/5000 kW while discharging. Energy absorbing screens are frequently explosive. Energy absorbing screens overload if the power in them cannot be used. An energy absorbing screen also acts more or less as a solar panel, producing 0.5 kW * D^2; this can actually be enough to reduce the discharge rate of the generator. *Dual*: the screen blocks attacks in both directions. It takes one turn for a dual screen to turn on or off. Depending on your drive technology, dual screens may also disable your drives. *Slow Flicker*: can turn on and off instantly, but still once/turn. *Fast Flicker*: can turn on and off instantly. To block an attack with a fast-flicker screen, while also attacking, requires a block roll -- treat PD as 4 unless using an active deflector. If there is no operator, assume the screen itself has a block roll of TL-6. If you are not attacking, no roll is required. The screen _must_ be operated by the same person as is controlling the weaponry. *Portal*: can open small holes in the screen to allow firing out. Treat as a fast-flicker screen, the holes are smaller but stay open longer. *Fixed-Tuned*: a certain wavelength can pass through the screen. This is an advantage for a dual screen, a disadvantage for other screens. Determining the wavelength the screen is tuned to requires an electronic operations (sensors) roll with a radscanner, with a penalty of TL-4; no penalty if the vehicle is actually using its weapons. 'Rainbow' Xasers and grazers are double cost, TL +1; their only benefit is the ability to change the frequency they are tuned to. *Variable-Tuned*: as above, but the wavelength can change dynamically; this takes 1 turn and an electrics(screen) roll. Rules Variants: alternate energy levels. All should be roughly equal in power to standard screens. *5% screen*: the screen has 20 energy levels, and gains one energy level at 40%, and again at 60%, 70%, 80%, 90%, and 100%. It loses one level every five seconds. *HP screen*: the screen has DR equal to 25% of the DR it provides, and HP equal to 250% of the DR it provides; it regenerates 1% of its hp per turn. *Ablative Screen*: the screen ignores hits up to 25% of its DR, and loses 1 DR per additional 5 damage; it overloads when DR drops below 25%. It regenerates 1% of its DR every turn. Sample screens: personal force screen (TL 13): SR 4 with ultra-compact option, diameter of 2 yards, DR 200, 20 kW(10.5 min), 2.5 lb with C cell, $4k backpack force screen (TL 13): SR 25 with ultra-compact option, diameter (max) of 5 yards, DR 500, 125 kW(17 min), 18 lb with D cell, $25k heavy force screen (TL 13): SR 100 with ultra-compact option, diameter of 10 yards, DR 1000, 500 kW(42 min), 70 lb with E cell, $100k. heavy force screen (TL 12): SR 100 with compact option, diameter of 10 yards, DR 1000, 500 kW (36 min), 270 lb with E cell, $100k. Traveller Black Globe Generator (TL 12): SR 250000, diameter 500 yards, explosive overload, rigid barrier, spheroidal, impermeable, double-obscuring (10), energy absorbing, dual, fast-flicker; Weight = 250,000*5*.5(explosive)=562.5 tons, Power = 250,000 * 5 * .01(energy absorbing) = 12.5 MW, Cost = 250,000 * 500 * .5(explosive) = $62.5M, DR = 100 * .8 (absorbing) * 2 (dual) * .75 (fast-flicker) * sqrt(250,000) = 60,000. Power output, while discharging, is 720 MW; as a solar absorber it produces 125 MW, which is more than enough to deal with its own power requirements.