VECTOR MOVEMENT IN BOOK 2 STARSHIP COMBAT
VECTOR MOVEMENT MADE SIMPLE
Nobody I know (locally or on the net) uses the vector movement system in Book 2 for space combat. It's too bad, too, because the Book 2 space combat system is extremely fun and very focused on role playing (I typically cut back and forth between what's happening outside/inside the ship...or you can just play Book 2 space combat as a typical map-style game...but I always make it visual and put the players there aboard ship.).
Part of the problem with Book 2 space combat movement is the way it's written. It turns people off.
Try this, though...
Simply take a piece of graph paper (or a big sheet you'd buy from an artists' supply store) to plot movement.
Each square = 25mm (represents 2500 km in the game world).
Then, forget using a protractor to figure degrees. Simply use the squares for generalized direction: 0 degrees; 45 degrees; 90 degrees; 135 degrees; 180 degrees; 225 degrees; 270 degrees; 315 degrees.
Each of the sides and points of a square is an allowed direction of travel, moving clockwise around the square. So, a ship traveling along a vector at 135 degrees would be travelling down the south right point of the square. 180 degrees is travelling due south on a square. 0 degrees is travelling due north on the map. Etc. Should be easy to figure out (just pick a "north" side to the map).
Now, as you play Book 2 space combat, you're moving your ship a number of squares each turn. Remember that 4 squares (at 25mm each) will equal 10,000 km in the game world. A 1G ship can accelerate or decelerate up to 4 squares per round. Multiply the ship's M-Drive G rating by 4, and this will be the maximum number of squares the ship can accelerate/decelerate each round.
So...
You've got a 3G vessel at relative stop on the game board. Your ship can accelerate up to a max of 12 squares per round, or any number of squares less than that. If you accelerate at max for 3 rounds, your ship will be moving at 36 squares per round. If you want to slow down, you can slow your ship up to a max of 12 squares (so it will take you 3 turns to slow down to relative stop again). In one turn, you could decrease speed from 36 squares to 24 squares per round (but no more in one round).
Remember that a vector is a measurment of both speed and direction. So, your ship's vector will always include it's direction.
Let's say the top of the map is considered "north". If this is true, then:
0 degrees is "north".
45 degrees is "north east".
90 degrees is "east".
135 degrees is "south east".
180 degrees is "south".
225 degrees is "south west".
270 degrees is "west".
315 degrees is "north west".
(Just to make this cool, consider "north" as Galactic North on the map.)
If a ship's vector reads: 16 @ 315 degrees
Then that ship is travelling "north west" at 16 squares per space combat round.
And, that's it. Vector movement made simple. Follow what I've written above plus the rules in Book 2 for space combat, and you're in for a romping good time playing some Traveller starship encounters.