Date: Tue, 17 May 1994 00:45:17 EDT
Sender: Mythus Fantasy Roleplaying Game List <[MYTHUS L] at [BROWNVM.brown.edu]>
From: "Rodney W. Morris" <[c s c 3 r w m] at [CABELL.VCU.EDU]>
Subject: ABYSS: Ship to ship combat (mostly ship movement)
Ship to Ship Combat for Abyss
Ship to Ship Combat, Summary
One: Pre-Combat Tasks
Two: Hitting an Opponent
(A) Determine initiative with a 1D10 roll. Deduct PNSpd and
add CS (Computer Speed) and any other speed factors as necessary.
(B) The attacker specifies the target and modifies the BAC
according to range, cover, and the like to find the FAC
Three: Applying Physical Damage
Four: Conducting Additional Attacks
Pre-Combat Tasks
Determine Control (only if ship previously damaged)
Movement
It is usually wisest to utilize the age-old hex-grid when
performing ship-to-ship combat. In the Dangerous Journeys system of
combat, each hex is equal to 1 km in space and 0.5 km in an
atmosphere of any type.
A ship's movement is determined in measurements of
Gravities. Gravitities are determined during ship construction and
are basically a calculation based upon ship mass, streamlining and
air resistance (if any) and engine power. A good engineer might be
able to "milk" a little more power from the engines, and that is
discussed in the determinations.
The measurement in Gs is half of how many movement points a
ship has in a vaccuum. In other words, a ship that can move at 5G
has 10 movement points. These points can be allocated in a number of
ways, as shown in the table below:
Table 1: Movment Ratios for Starships
1 MP 1 hex forward per CT
2 MP to sideslip left or right or to move
backwards without grav plates or
multiple engine drives
1 MP add a modifier of +1 to the ship's
dodge factor
1 MP to begin turning the vessel 1 hex
facing per CT without changing
forward momentum
In a weightless environment, any movement will continue to
move at that speed until a force slows or prevents such movment, in
which case that energy is transferred to the stopping force. Thus, a
ship that has spent 1 MP to move in a specific direction will move
in that direction until it stops itself or contacts a force with a
different direction and force of movement. Unless a ship is
outfitted with four engine drives or utilizes grav plates, it will
take double the amount of movement to change direction, as shown in
Table 1. This forward movement is termed momentum.
A ship can move against its momentum (the direction in which
it is currently heading) only so quickly. If a ship attempts to
move against its momentum, it can become damaged, if it exceeds the
structural rating of the starship. Moving against the momentum
includes high-speed turns and stopping (reversing course). A ship
can also move only so fast, as according also to its structural
rating.
A ship that is attempting to turn must effectively alter its
momentum to a new direction, unless is merely wishes to change
facing. Such a turn is dangerous at high speeds. There are two
methods to turning a starship. The first method uses the engine
drives to change the momentum; it is a maneuver of the desperate.
This movement will change the facing of the starship without any
additional costs from the maneuver drives. To turn a starship
30(half a hex facing) in this manner, one must spend a number of
MPs equal to the momentum of the new direction (i.e. the speed of
the craft after changing its course) plus a fourth of the current
momentum. To change the heading by 60(or 1 hex facing), one must
spend a number of MPs equal to the momentum of the new direction
plus a third of the current momentum. To change heading by 90(a hex
and a half), one must spend a number of MPs equal to the momentum of
the new direction plus half of the current momentum. To change
heading by 120(two hex facings), one must spend a number of MPs
equal to the momentum of the new direction plus two thirds of the
current momentum. To change heading by 150(two and a half facings),
one must spend a number of MPs equal to the momentum of the new
direction plus three quarters of the current momentum. To change
heading by 180(three hex facings...a dire situation indeed!), one
must spend a number of MPs equal to the momentum of the new
direction plus the current momentum. These manuevers can only be
performed by ships with more than one engine drive. A single-engine
starship will have to rely upon the second method.
The second method of changing direction is not nearly as
dangerous, but it takes considerably more power to perform. This
method utilizes the maneuver drives and the engines in conjuction to
change heading. To turn using this method costs double the momentum
of the new direction (again, the speed of the craft after changing
its course) plus the amount of current momentum as described in the
first method (i.e. plus a fourth of momentum for a 30turn, a third
of momentum for a 60turn, etc.). If the ship has a single engine
drive only, the second variable is multiplied by 1.5. If the ship's
engine drives are inoperative or don't exist, the second variable is
mulitplied by 2.
Turning costs are summarized in table 2.
Table 2: Ship Turning MP Costs Summary
Cm= Current Momentum
Dm=Momentum after change in heading
Emergency movement utilizing dual or greater engine
drives only
30turn (half a hex facing) = Dm + 25%Cm
45turn (a full hex facing) = Dm + 33.3%Cm
90turn (a hex and a half facing) = Dm + 50%Cm
120turn (two full hex facings) = Dm + 66.6%Cm
150turn (two and a half hex facings) = Dm +
75%Cm
180% turn (three full hex facings) = Dm + Cm
Movement utilizing maneuver drives and dual or
greater engine drives
30turn (half a hex facing) = 2Dm + 25%Cm
45turn (a full hex facing) = 2Dm + 33.3%Cm
90turn (a hex and a half facing) = 2Dm +
50%Cm
120turn (two full hex facings) = 2Dm +
66.6%Cm
150turn (two and a half hex facings) = 2Dm +
75%Cm
180% turn (three full hex facings) = 2Dm + Cm
Movment utilizing maneuver drives and a single
engine drive
30turn (half a hex facing) = 2Dm + (1.5 x
25%Cm)
45turn (a full hex facing) = 2Dm + (1.5 x
33.3%Cm)
90turn (a hex and a half facing) = 2Dm +
(1.5 x 50%Cm)
120turn (two full hex facings) = 2Dm + (1.5
x 66.6%Cm)
150turn (two and a half hex facings) = 2Dm +
(1.5 x 75%Cm)
180% turn (three full hex facings) = 2Dm +
(1.5 x Cm)
Movement utilizing maneuver drives only
30turn (half a hex facing) = 2 (Dm + 25%Cm)
45turn (a full hex facing) = 2 (Dm + 33.3%Cm)
90turn (a hex and a half facing) = 2 (Dm +
50%Cm)
120turn (two full hex facings) = 2 (Dm +
66.6%Cm)
150turn (two and a half hex facings) = 2 (Dm
+ 75%Cm)
180% turn (three full hex facings) = 2 (Dm +
Cm)
Movement in the void of space or just atmospheric fighting
requires different heights. These heights are notated by number
from the pre-determined plane of "0" (herein called the 0-Plane).
In other words, a ship that spends 1 MP to climb, relying upon its
momentum to continue it moving forward, will continue forward the
amount of hexes it momentum would carry it and has a height of 1
level away from the 0-Plane. It will continue to move in this
direction unless momentum is halted. A ship's total movement is
calculated by adding its movment away from the 0-Plane and its
movement across the 0-plane. In other words, a ship with a momentum
of 2 hexes and an ascent of 1 level is considered to be
moving at three hexes per round. If this ship were to slow its
ascent (by expending 2 MPs), it would return to its movement to two
hexes per round (its momentum) and remain at a height of +1. A ship
that descends below the 0-Plane will have a negative notation (-1).
Movement During Combat
Whichever ship's captain wins initiative (a d% roll + the
computer's rating + the pilot's STEEP rating in Space Tactics), he
chooses which ship goes first. The captain who won initiative
second chooses who goes second from those left and so on until the
order of battle for that turn is determined. If one player is
controlling many ships, whoever is designated as wing-leader rolls
the die against his Space Tactics K/S (usually, the wing-leader is
the best pilot, also). The GM can divide the rolls up between the
OP ships as he sees fit. The ships are selected singly, so that if
only two opponents are playing with five ships apiece, the one who
won initiative will pick a ship to go first, then the loser of
initiative will go second, the winner third, and so on until all
ships are selected.
After initiative is determined and order of battle
established, the player chosen to move first does so. The moves of
the vessels are broken up into five different rounds of combat,
during which time they are permitted to fire and defend themselves
after each move.
The movements are broken up as follows, in primary numbers.
For a primary number, such as three, use the movement as listed.
For any combination of primary numbers, add the numbers in that
round together. For example, a ship with MP of ten (2+3+2+3) would
move two hexes in the first round (1+1), two hexes in the second,
and so on. Make the smallest amount of additions possible (i.e. in
the above example, do not add 2+2+2+2+2). The primary numbers are
given in bold on the table below. The normal numbers are examples.
Round
MP 1 2 3 4 5
1 0 0 1 0 0
2 0 1 0 1 0
3 1 0 1 0 1
4 1 1 0 1 1
5 1 1 1 1 1
6 1 1 2 1 1
7 1 2 1 2 1
8 2 1 2 1 2
9 2 2 1 2 2
10 2 2 2 2 2
13 3 2 3 2 3
15 3 3 3 3 3
25 5 5 5 5 5
50 10 10 10 10 10
75 15 15 15 15 15
100 20 20 20 20 20
Maneuver drives are basically an additional pool of MP used
to maneuver during combat. Just like with thrusters, the MP are
figured out by multiplying the G factor by 2. Thus, a maneuver 4
would be able to supply an extra 8 MP to movement for that round.
Momentum still comes into play here, so if a ship uses manuever
drives to sideslip, it must pay a total of four points to remain
moving in the same direction it started from; otherwise, it will
continually sideslip.
If a ship ever exerts more Gs than its structural rating, it
will take damage from the maneuver. If a ship attempts a full
reverse of momentum of any kind, it might sustain damage.
Basically, the maneuver drives would be pushing against the entire
bulk of the ship. If an attempt is made to full reverse and
continue on a course completely opposite from the former course, the
ship could easily be torn apart. Most ships are outfitted with
manuever drives that will detach before tearing the superstructure
of a ship, but it is a fairly inefficient means of situating the
maneuver drives (they tend to allow for less maneuvering power).
Civilian spacecraft are almost always outfitted with detachable
maneuver drives, by law.
To figure out how many Gs a ship is exerting at any time,
add the total movement for that round and multiply by 2.5
(multiplied by five for the total rounds in a turn and divided by
two to find the total Gs. The result will show you how many Gs a
ship is committing. For example, a ship has used 10 MP from its
thruster drives to move forward. It has a maneuver drive of 8,
giving it a pool of 16 points. A large asteroid is hurtling at the
ship's location. The pilot, on the second round of movement,
commits to a full reverse, utilizing all of his maneuver MP ( 16
points) to do it. This would send his ship hurling backwards
at 6 hexes per round (for the rest of the turn!), exerting 13 Gs
that round on the superstructue of the ship. If the asteroid were
hurtling up behind him, he could spend the 16 points and raise his
forward momentum to 26 hexes per round, exerting 13 Gs for each of
the next three rounds. He'd better hope that superstructure holds
up (not to mention his inertial dampeners).
Applying Damage
Damage is applied to a ship depending upon its
configuration. The configurations utilized by the UCSS is listed
and described below.
Configuration A
This configuration is utilized for the smallest of fighter
craft. Such a craft has one engine and little else but weapons.
The pilot is customarily lying down on his or her stomach during
flight and enters from the top or bottom. Auxiliary craft are
usually non-existant, though some have an escape capsule built into
the cockpit. Such a craft is often winged, to facilitate
atmospheric flight.
Configuration B
This configuration is meant to be a short-ranged bomber,
usually launched from a larger ship.