3d zero-g combat

[cerebrolator]

I'll be running a scenario soon that features zero-g combat. Some of the battle spaces will be big enough to make elevation important. I'm trying to think of a good way of portraying this on a battlemap so the players can be more tactical in their actions. Any suggestions on how to make such a battlemap? Has anyone on the boards done this before?

 

[rust]

Any suggestions on how to make such a battlemap? Has anyone on the boards done this before?

For space combat games we sometimes used differently coloured mar-
kers, matchboxes or small boxes made of clear plastic to show the ele-
vation by putting the relevant markers or number of markers under the
miniatures.

 

[alex_greene]

Oh, good luck computing the vectors. I see the vector analysis pages, and my eyes water halfway down the first page when they start getting into matrices :shock:

Abstract the movement rules with Zero-G and Tactics skills. If you have a 2d space, keep track of where the units are with counters in the squares but make sure to keep tabs of the vertical displacement, again in squares.

If the characters need to make a change in course (assuming they can, e.g. they have a reaction propulsion pistol or a grav belt) roll the skill below:-

Zero-G, Dexterity, 1-6 seconds, Average(+0) for Belters and Spacers, Difficult(-2) for flatlanders, Very Difficult(-4) for people with a Honeworld Size 9+.

The character gets 1 point per Effect in the skill. If he can make a course change in a given combat round, he can apply points against all three axes of motion - X, Y and Z. Assuming free floating unaided, the character will continue to travel along that line till he reaches an obstruction.

So, for instance, a character is at 5, 6 where he meets the wall at 3 squares up. He kicks off, and makes a roll with an Effect of 4; he kicks up, across and out, assigning 1 square per round to his X axis, 1 square per round to his Y axis and 2 points to his Z axis motion.

Next round, the character will be at 6, 7, 5; the round afterwards, assuming nobody bangs into him, he will be at 7, 8, 7.

If two bodies in motion collide, e.g. two moving fighters travelling with different vectors, add their X, Y and Z components separately. Assume the characters travel as one unit from then on in until one or both can make a Zero G roll to kick away from the other on a new vector.

e.g. Our boy above is travelling with a vector of (+1, +1, +2) when he bangs into his partner who'd been travelling very fast straight down - (-2, -3, -3). Adding the vectors together, you get two bodies now moving at a vector of (-1, -2, -1). If they'd not been stunned by the impact - have them both roll End to avoid - they can either separate from one another and take up new vectors away from each other, or keep floating together till they both reach the nearest surface.

It's a simple version of the rules, but it beats faffing about with dot product and cross product and calculus.

 

[cerebrolator]

Thanks for the tips!

Alex, which vectors are you talking about? I only have the core book. Does one of the other books cover zero-g combat in more detail or am I missing something in my reading of the core book?

 

[alex_greene]

It's somewhat like the optional tactical system described in High Guard. You have to compute where a body is (origin), where it wants to go (destination) and the change of course necessary to get there (vector) - and, of course, it isn't in 2d, but in 3d - which means you're trying to work out left/right, forward/back and up/down.

Three axes of motion. Unless you're Khan Noonian Singh on board the USS Reliant in the Mutara Nebula. Then you only use two.

 

[cerebrolator]

Three axes of motion. Unless you're Khan Noonian Singh on board the USS Reliant in the Mutara Nebula. Then you only use two.

Yeah and we know where that gets you! :shock:

 

[alex_greene]

This whole thing brought back all my old school lessons, about inelastic and elastic collisions, conservation of momentum, conservation of energy and a whole lot of boredom. Mostly because they were asking us to use logarithm tables for bloody everything, and I was working out the answers in my head.

It was the one aspect of Physics and Applied Maths lessons for which I had the least enthusiasm, kind of like those ridiculous exercises with the weight on pulley wheels and a can perched on a board with a given coefficient of friction that is being tipped up - does it slide first or topple over, and at what angle does Something Interesting Happen?

 

[cerebrolator]

So how would you handle weapons fire in these situations? I know that the core rulebook has recoil affect initiative if it is greater than the character's strength modifier. In a zero-g situation, wouldn't the recoil from a weapon affect movement? I don't know that the recoil numbers listed for the weapons would make sense in this situation either. I can see lasers lacking recoil but all slug weapons would have recoil, I think. (Physics isn't an area that I delved too deeply into; neuroscience is more my forte.)

 

[rust]

Even laser weapons would have a recoil, not enough to be felt under
normal conditions, but perhaps strong enough to influence movement
under zero-g conditions. However, for game purposes I would ignore
it.

Otherwise I usually demand a zero-g combat skill roll whenever a cha-
racter fired a slug thrower under zero-g conditions. Until such a skill
roll has succeeded, the character has not yet re-oriented himself and
is unable to act.

By the way, with zero-g combat there is a certain danger to "overthink"
and slow down the game by considering too many variables. Unless
you want a realistic simulation of such a combat, better keep it some-
what unrealistic and fast paced instead. :wink:

 

[Galadrion]

Laser and other "purely" energy weapons would have effectively zero recoil; they do have some small amount, but it's so small in comparison to the masses involved - even the mass of the weapon itself - that you'd drain the battery pack before significantly altering the vector of the character. Now, anything that fires a payload with mass is going to have a more noticible recoil. I'd rule that any mass-payload weapon not specifically designed for zero-g (such as a gyrojet-type weapon) could affect vector - roll Zero-G skill to avoid adding 1 to your vector in the opposite direction from firing, if you want to avoid it. Use the recoil rating of the weapon as a negative DM for more "realism". This is a grossly simplified system, but the main goal is playability and entertainment, not a hard simulation of combat under conditions we've never seen. Otherwise, I'd also be mentioning tumbling effects, greater vector additions for more powerful weapons, and so forth...

 

[alex_greene]

You'd tumble if your Zero-G roll had an Effect of 0 or less. Your current vector would probably be determined based on your last vector, probably unchanged unless you hit something. Shooting anything would be done with a penalty equal to the Effect of the failed Zero G roll. Also roll End 8+once per turn to avoid chundering all over everything.

 

[cerebrolator]

Thanks for all the input! I have a much better feel for how to handle our next gaming session.