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.