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|
Advanced Phase World Starship Rules |
By: Kitsune (Kitsune@vabch.com)
Reformatted by: Dustin M. Ramsey (DustinM@rifts-rpg.com)
[Reprinted by special permission of the author]
I am a heavy reader of science fiction and am very choosy about what I read. Compared to most Science fiction (including Star Trek Novels, Babylon 5, and David Weber's "Honor Harrington" series) the non FTL (Faster than Light) speeds of starships in Phase World are far to slow. A good example of this is how long a Phase World starship would take to travel from the Earth to Mars. Based on how long it takes our probes to get there and how fast they are, it would take years for Phase World starships to go from the Earth to Mars. Additionally, while C.J. Carella wrote that Phase World starships are more advanced than their Robotech or Macross counterparts, simply comparing the starships from these three different dimensions shows that Robotech ships have vastly different top speeds and weapon ranges that dwarf those of the other games.
Table of Contents:
Starship
Speeds
Starship
Acceleration
Starship
FTL Modifications
Energy Weapon
Ranges
Missile Ranges, Top Speeds,
and Accelerations
How to Treat Speeds and
Ranges
Starship Speeds:
Phase World starships are theoretically capable of reaching .99 of the speed of light, however it is a starship's radiation and particle shields that limit how fast these starships can actually travel. Because larger ships can mount heavier and more effective radiation and particle shields, they can reach a higher top speed than smaller starships. This is somewhat equaled out by the fact that smaller ships generally have a higher top-end acceleration. With the exception of Runners (which have military grade shielding), most civilian ships have a lower top speed than military ships because civilian designers are unwilling to invest as much space for shielding.
Top Speeds:
(Note: these figures are meant for an average Sol type solar system.
Systems with higher particle densities would require lower top
speeds.)
|
|
||
|
Ship Class: |
Size: |
Maximum Speed: |
|
Capital Ships |
6,000 tons and greater |
60% of light |
|
Heavy Fighters, Bombers, Runners |
250 tons and greater |
50% of light |
|
Star Fighters |
5 tons and greater |
40% of light |
|
Space Combat Power Armors & Robots |
Varies |
20% of light |
|
Civilian Ships |
Varies |
20% of light |
Robotech starships are also reduced for the same reason. Their particle and radiation shielding are not at Phase World standards which only allows the starships to reach the listed book ranges. If their radiation and particle shields were raised up to the standards for Phase World then they to would have the same top-end speeds. This does not include Robotech and Macross star fighters because they are basically short range craft, which could take advantage of the higher speeds available with engine upgrades.
Robotech: Sentinels fighters are much slower that what should be expected in space, so instead of the 75% increase, revise the speed of the ship to four times the vehicle's normal speed.
Mutants in Orbit starships are similarly effected by the same rules. A starship's top speed is limited by the ability of its radiation and particle shielding. Ships with traction drives can reach up to 20% of the speed of light (equal to Phase World civilian shields) and ships with other types of engines can go up to four times greater than their listed speed when they are in space. This also includes Rifts Earth vehicles if they can break atmosphere.
Starship
Acceleration:
In many ways a starship's acceleration is much more important that its top speed. Starship acceleration is affected by two factors: the capability of the starship's drive and the ability of the artificial gravity system to compensate for the starship's acceleration. If the artificial gravity system fails while a starship is accelerating, S.D.C. beings would be turned into jelly, and M.D.C. creatures such as the Kreegor would be killed when every bone in their body shatters. Completely solid organisms such as the machine people would survive, but would not be unable to move.
A starship's acceleration can be calculated by dividing its Mach speed by ten. This becomes the ship's acceleration, as expressed in a percentage of the speed of light per turn. This generally means that small ships (like star fighters) have a much faster acceleration rate than large ships (such as capital ships).
Example 1: A Black Eagle has a maximum speed of Mach 16. This means that the starship's acceleration is 1.6% of the speed of light per turn.
Example 2: A Warshield cruiser has a listed speed of Mach 8.5. This means that the starship can accelerate at up to .85% of the speed of light in a turn.
A ship can exceed its top acceleration by up to three times its normal acceleration rate, but there is an 18% chance of the engine burning out each turn. If the engine burns out, emergency systems will allow the ship to accelerate up to .2% of the speed of light. This means that starships with burnt out engines take a very long time to speed up and slow down. In addition to the chance of engine failure, there is a 1% chance per turn that when a ship is accelerating above maximum, its artificial gravity will fail and kill most of the crew.
There are two final areas that needs to be described: mass and inertia. The mass of an object increases as the speed of light is approached. This means that once a starship reaches 50% the speed of light, the ship's rate of acceleration is halved. Additionally, as a ship approaches the speed of light, its inertial mass is dramatically increased. This can be calculated with the following formula:
(where v = velocity and c = speed of light)
The following table illustrates this:
|
|
|
|
Speed (c): |
Gamma: |
|
0 |
1 |
|
0.2 |
1.021 |
|
0.3 |
1.048 |
|
0.4 |
1.091 |
|
0.5 |
1.160 |
|
0.6 |
1.250 |
|
0.7 |
1.400 |
|
0.8 |
1.667 |
|
0.9 |
2.294 |
|
0.95 |
3.203 |
|
0.99 |
7.088 |
|
1 |
-> infinity |
The apparent length of the starship is divided by the gamma factor, and the apparent time is slowed by this factor. The momentum and kinetic energy of the starship is increased by the factor, so it's apparent inertial mass (not gravitational mass) is also increased by this factor. In game terms, this all means that a starship acceleration is divided by the Gamma factor to calculate the ships new acceleration. In practical terms, this does not need to be worried about until 50% of light has been achieved.
Robotech and Macross starship accelerations use the auxiliary engines speed divide it by ten and that is the starship's acceleration in a percentage of the light.
Example: Ikazuchi Command Carriers have a top speed on its auxiliary engines of Mach 7. The starships acceleration would be .7% of the speed of Light. Note: this rule does not effect most small ships such as star fighters; they keep their Mach speeds as their top speed unless they are upgraded.
Mutants in Orbit The only kind of ship that can reach such high speeds is the traction drive ship. As the book says that these ships would take up to a year to reach .99 of light (limited by shields), the ship's acceleration is about .00005 percent of the speed of light per turn.
Starship FTL
Modifications:
Before going FTL, a starship must not be inside a gravity well. Since the strongest gravity source in a solar system is normally the star, these distances are measured from the star itself. It should be noted that these figures are based on a star that is the size of Sol (our sun); in order to modify the distance from the celestial object for the actual mass of the celestial object, you simply multiply the celestial objects mass in Sol masses by the distances. This means that White and Blue Giant class stars would have very large areas that a ship must clear before going FTL and gas giant planets would still have a relatively large distance that a ship must travel away from before entering FTL.
This distance is calculated by taking the largest distance that the drive requires, dividing that number by 1000, with the resulting figure showing the distance necessary as measured in light minutes. (A light minute is a convenient distance to express longer distances. The distance from the Earth to Sol is approximately 8 light minutes.)
Phase Drives:
Instead of Phase Drives being effected by the atmosphere of a planet,
they are effected by gravity. If a ship tries to activate its P-drive
too far inside the gravity well of a celestial object, the ship will
be ripped apart. When using a P-drive with a star the size of Sol,
the ship must be at least 20 light minutes away from the star. (The
original distances listed in the Phase World book is 10 to 20
thousand miles.)
Contra-Gravitonic Drives:
The distances for a CG-Drive is increased the same way that it is for
P-Drives. This means that instead of 20 thousand miles the distance
is 20 light minutes. (In the Phase World book, the distance is
written as 10,000 miles, but it states that double is safer so I am
using the larger figure)
Rift Jump Drives:
Instead of being effected by just the gravity and ley lines of the
planet, a starship with Rift Jump drives affected by the gravity and
ley lines of the entire system. The distance needed for the R-drive
to be used is based on the magic in the system. A system that has
very low magic only requires a distance of 5 light minutes, while a
system with a great amount of magic will require a distance of 50
light minutes before being able to activate the R-Drive.
Spacegate Jump Systems:
These systems are the only exception to the distances for the FTL
propulsion systems. This is because they work on a completely
different principle. Space gates may be near a planet without
interfering with their ability to be used.
Energy Weapon Ranges:
The ranges written in the Phase World book are far shorter that those of capital scale weapons in either the Robotech or Macross RPGs. While many science fiction programs seemingly show ships very close together, that is an illusion meant for viewers only. In a Babylon 5 episode they had a group of White Stars craft attack a group of Earth Force Destroyers. While the ranges appeared to only be a few thousand meters. The ranges stated were around 10,000 km. To equal out Phase World starship weapon ranges, all weapons are increased. In addition, rail guns are assumed to fire their projectiles at incredible speeds and do not propose a problem for the ships firing them.
Capital Scale Weapons:
This includes all weapons on capital scale starships that do 1D4
x 100 M.D.C. or greater. The ranges of the weapons are changed as
follows:
|
|
||
|
Environment: |
New Weapon Range: |
Special Notes: |
|
Underwater Range |
Equal to the book-listed range in an atmosphere |
Underwater Range is generally never more than 1/2 the Atmospheric Range |
|
Atmospheric Range |
Equal to the book-listed range in space |
None |
|
Space Range |
Equal to 1000 times the book-listed range in space |
Space Range is generally at least 1000 times the Atmospheric Range |
Example 1: A Warshield Cruiser's main battery has a range of 10 miles in an atmosphere and 100 miles in space. The modified ranges would be that the weapon has a range of 10 miles underwater, 100 miles in an atmosphere and 100,000 miles in space.
Example 2: The secondary batteries have no listed space range. The range listed is 16 miles. This becomes the weapons underwater range, The atmospheric range becomes double listed range to 32 miles, and space range becomes 16,000 miles which is 1000 times listed range.
Star Fighter Scale Weapons:
This includes all of the lighter weapons on capital ships, all
energy weapons on star fighters and other small ships, and the
weapons on space robots and power armors. The ranges for Star Fighter
Scale weapons are modified as follows:
|
|
||
|
Environment: |
New Weapon Range: |
Special Notes: |
|
Underwater Range |
Equal to the book-listed range in an atmosphere |
Underwater Range is generally never more than 1/2 the Atmospheric Range |
|
Atmospheric Range |
Equal to the book-listed range in space |
None |
|
Space Range |
Equal to 100 times the book-listed range in space |
Space Range is generally at least 100 times the Atmospheric Range |
Example: the rail gun on a SF-69 Scorpion Star Fighter has a book-listed atmospheric range of 8 mile and a book-listed space range of 16 miles. The new ranges will become 8 miles underwater, 16 miles in space, and 1600 miles in space.
Capital Scale weapons in Robotech and Macross are not adjusted. This gives them a small range superiority over similar Phase World weapons. Robotech: Sentinels states that lighter energy weapon ranges should be increased from 75% to 100% in space.
Star Fighter Scale weapons in Robotech and Macross are instead quadruped (x4) in space as compared to their listed ranges. This also applies to Rifts Earth vehicles in space and Mutants in Orbit vehicle weapons
Missile Ranges, Top Speeds, and
Accelerations:
In the Phase World books, you get the impression that starships lumber towards each other, not firing any energy weapons until they are at rock throwing ranges (100 miles or less) and not launching missiles until they are only 1 or 2 miles away from each other. I prefer a much more dynamic starship and missile combat. Space-based missile ranges have been vastly increased, and missiles now travel and accelerate at percentages of the speed of light. These changes mean that missile fire commonly starts at ranges greater than 1 million miles.
Missiles are not effected by a maximum speed because the missile's life span after launch is brief enough that radiation and particle damage is not generally a factor. (Less than 1% of all missiles do not reach their targets because radiation or particle damage causes them to destroy themselves, become inert, or veer off course.) Missile acceleration is calculated similarly to starship acceleration, except the top speed is higher.
Extended Range Engagements:
Missiles can be used to hit targets beyond their maximum range
because missiles will travel in a straight line once they run out of
energy. They are of course effected by gravity wells but that can be
calculated for.
- Targets that do not move are ideal for this type of strike. These include, among other things, orbital bases and cities. There is no bonuses or penalty to hit these targets.
- To hit specific targets, such as a specific city building, the missiles are at -8 to strike.
- To hit a large moving target such as a Capital ship (Protector or Dreadnought for example), the missiles are at -16 to strike and unlike most attacks, the pilot can make dodges.
Targets smaller than about 5 million tons cannot be hit if they have the ability to dodge. This is due to the amount of time that it takes for the missile to reach its target and the fact that the ship has plenty of time to move out of the intended path. However, this is only true for missiles that are fired from beyond their listed maximum range.
Cruise Missiles:
Missile range is 8000 miles (12,875 km) in an atmosphere and
4,000,000 miles (6,437,376 km or 21.5 light seconds) in space.
Missile has a top speed of Mach 25 in an atmosphere and in space has
an acceleration of 10% of light per turn (far faster than any
starship)
Long Range Missiles:
Missile range is 3400 miles (5470 km) in an atmosphere and 1,800,000
miles (2,89700 km or 9.7 light seconds) in space. Missile has a top
speed of Mach 20 in an atmosphere and in space has an acceleration of
8% of light per turn (far faster than any starship)
Medium Range Missiles:
Missile range is 160 miles (257.5 km) in an atmosphere and 80,000
miles (128,750 km or 0.43 light seconds) in space. Missile has a top
speed of Mach 15 in an atmosphere and in space has an acceleration of
6% of light per turn (faster than any starship except a fighter
exceeding its maximum safe acceleration)
Short Range Missiles:
Missile range is 10 miles (16.1 km) in an atmosphere and 500 miles
(804.7 km) in space. Missile has a top speed of Mach 10 in an
atmosphere and in space has an acceleration of 4% of light per turn
(faster than any starship except if it is acceding it maximum safe
acceleration)
Mini-Missiles:
Missile range is 2 miles (3.2 km) in an atmosphere and 100 miles (161
km) in space. Missile has a top speed of Mach 10 in an atmosphere and
in space has an acceleration of 2% of light per turn (slightly faster
than any starship except if it is exceeding its maximum safe
acceleration)
Robotech, Macross, Rifts Earth, and Mutants in Orbit missiles are not treated the same way although the launcher could easily be changed to the Phase World launchers. For Robotech: Sentinels, missile speed and range is 4 times that listed in the book.
How to Treat Speeds and Ranges:
The speed of light is 186,282.4 miles per second (299,729.458 km per second) in vacuum. This is to allow the person to do calculations with starship speeds/accelerations and weapons ranges. It is important to note that a starship cannot just travel in two dimensions but can travel in three dimensions and that in order for a ship to change course it must exert acceleration to make it move in the direction.
Example: a Black Eagle is traveling at 10% of the speed of light it wants to turn to port. In one turn its course is now 10% of the speed of light forward and 1.6% of the speed of light to port. Another point to remember is that when in an intercept course, the firing ranges can be very brief and that the best courses for extended engagements are either parallel courses or pursuit courses.
There are three basic methods of doing calculations:
- Keep track of speeds, ranges, altitudes, and ranges in your head. For large combats, this and educated guesses is probably the best method.
- Use graph paper, writing down the vertical position of the starship and calculating from there. This can work with relatively small battles.
- Using the stands for aircraft combat, come up with a scale and use them. This method also works for relatively small battles.
[ Phase World™, Kreegor™, and Mutants in Orbit™ are trademarks owned by Kevin Siembieda and Palladium Books, Inc. ]
[ Rifts® is a registered trademark owned by Kevin Siembieda and Palladium Books, Inc.]
[ Robotech® and Robotech: Sentinels are registered trademarks owned and licensed by Harmony Gold USA, Inc. ]
[ Macross® is a registered trademark owned and licensed by Big West/Bandai. ]
[ "Honor Harrington" is copyright © David Weber and Baen Books. ]
[ Star Trek is copyright © Paramount Pictures. ]
[ Babylon 5 is copyright © Warner Brothers Television. ]
By Kitsune (Kitsune@vabch.com).
Copyright © 1997, Kitsune. All rights reserved.
I would like to recognize Chris Curtis (c-curtis@tamu.edu). as helping with many of the ideas listed here
I would also like to thank Malcolm Edwards (malcolm@fedu.uec.ac.jp) for helping me with the effects of approaching the speed of light on acceleration and time dilation.