Topic: Designer's Notes: Vector Movement
In this second mini-article related to design choices in the new edition of Starmada, we'll take a look at the movement system, and how it reflects the "reality" of movement in a frictionless environment. Technically, the movement system is unchanged from Starmada: The Admiralty Edition. Ships will still be able to maneuver in exactly the same ways as they could in SAE. However, the process by which players determine the movement of their ships has been streamlined, hopefully making the game more fluid and easier to understand.
There are a few assumptions underlying this system:
1) A thrust of 1 represents enough force to accelerate a ship by one hex per turn. Also, thrust is applied immediately, meaning that a ship accelerating from stop to 3 hexes/turn moves three hexes. (If thrust were applied evenly throughout the turn, a ship that accelerates from 3 to 7 hexes/turn would only move five hexes.)
2) The direction in which a ship is facing indicates the direction of travel. Strictly speaking (as anyone who watched fighters zip about in the Babylon 5 TV show could tell you) it is possible for spacecraft to apply thrust in one direction and then spin around to face the opposite direction. However, to simplify record-keeping, it is assumed that a ship's heading and its facing are always the same. (The "Pivots" optional rule changes this.)
3) The amount of thrust required for a ship to complete a given maneuver is determined by comparing its vector at the start of the turn with its vector at the end of the turn. (A ship's "vector" is the combination of its speed and its heading.)
So much for the philosophical underpinnings -- let's get to the actual process. In order for this to work, it is necessary to keep track of each ship's speed. This was done in SAE by writing it on each ship's data card; in the new edition, we introduce "speed markers". Either method works fine.
To determine a ship's movement options, compare its speed to its thrust rating. There are three possible types of move, or "Maneuvers". If the ship's speed exceeds its thrust, it may only perform a "Straight Ahead" maneuver; otherwise it can perform any of the three:
1) STRAIGHT AHEAD: The ship MUST move a number of hexes equal to its speed minus its thrust (to a minimum of zero), and MAY move a number of hexes equal to its speed plus its thrust. The ship cannot turn.
2) COME ABOUT: The ship has no minimum move requirement, and MAY move a number of hexes equal to its thrust. The ship must turn once during its move.
3) REVERSE COURSE: The ship has no minimum move requirement, and MAY move a number of hexes equal to its thrust minus its speed. The ship must turn two or three times during its move.
As an example, if a ship has a speed of 3 and a thrust of 5, it can do one of three things:
STRAIGHT AHEAD: Move between zero and 8 hexes, making no turns.
COME ABOUT: Move between zero and 5 hexes, making one turn.
REVERSE COURSE: Move between zero and 2 hexes, making two or three turns.
However, if the ship has a speed of 5 and a thrust of 3, it can only do one thing:
STRAIGHT AHEAD: Move between 2 and 8 hexes, making no turns.
A ship's new speed is equal to the number of hexes moved. That's it!
Majestic Twelve Games
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