Combat in 3D environments.

3D Combat Risers - Deluxe Set - Clear Mithril
3D Combat Risers for Game Simulation

Back in 2016 I wrote this BLOG that I want to revisit a bit due to some recent work. I wanted to start a discussion on combat in 3D environments with a focus on 3 “terrains”: underwater, aerial. and zero g. While there are specific challenges to each of these, they all share 1 specific trait–the ability of characters to maneuver and fight in 3 dimensions. Before I delve into this, a small disclaimer. There is probably rules for each of these in one of the dozens of RM supplements. I don’t have any of them and I’ve read even fewer. I might be going over “old ground”, but for purposes of this blog, we can also discuss how this might work in RMU. I’m not aware of any rules in the new version for 3 dimensional interaction.

Rolemaster combat assumes combat will occur on a hard surface and attacks will come from front, flank and rear (and maybe overhead on occasion). When you add in a third level of coordinates AND the ability of a players to rotate, turn and pivot simultaneously then things can get more interesting. How should this be handled? There might need to be a separate set of rules for each situation, but conceptually they are similar enough that a shared mechanic might be possible.

Underwater. For anyone experienced with snorkeling and/or diving knows that it can take time to feel comfortable with varying degrees of orientation underwater. But with some skill it’s easier to swim upside down, inverted or rotate comfortable and maintain perspective. But non-native swimmers don’t move through liquid easily or quickly. The resistance of water, lack of fins or flippers and encumbrances of clothing and equipment make movement slow, fast weapon attacks extremely difficult and thrown weapons entirely useless. From a pure movement mechanic perspective, perhaps a simple approach is to set a underwater movement rate/rnd and then establish a % of activity from normal baseline. Other rules could be developed around increased damage from vacuum spells, decreased damage from heat/fire etc.

Zero G. In some respects, Zero gravity is the opposite of underwater: inertia, momentum and mass over enhance basic movements and there is no real force except hard objects or force to offset momentum. Not having real life experience in zero gravity it’s hard for me to intuitively model game mechanics. One idea I have is to leave movement rate the same, but require MM roles to maintain orientation, change or stop an action and orientation roles anytime a change occurs.

Aerial. It’s easy to think of aerial combat in terms of our own experience with lift and thrust. Assuming a magical flying mechanism does not require momentum to generate lift, than aerial combat is a combination of underwater and zero g. A bit of limitless rotation and orientation but with two resistance forces: gravity and inertia.

There are really two overarching issues to tackle: environment specific mechanics that effect movement, combat, spells, breathing etc and the resolution of player orientation, attack vector, environmental awareness and perceptual capacity. This last piece feels like it could be dealt with using a simple unifying mechanic.

In my own adventures, Priest-King has a significant amount of underwater adventures, Empire of the Black Dragon has both underwater and zero g and Legends of Shadow World has some zero gravity as well. I generally GM it with a loose hand and the players tend to find fixed “anchors” to launch from, provide protection from some directions and minimize disorientation.

Does anyone have any thoughts or innovations?

4 thoughts on “Combat in 3D environments.”

  1. I think part of this depends on how rules heavy or rules lite you want to go. For what I’m working on now, I have what might be considered static skills for Underwater Combat which allow players to reduce or negate associated penalties and use certain weapons and attacks underwater. Characters without that specialization will have significant penalties reflecting what you mentioned (difficulty moving, orientation, and so on). My approach is obviously more rules lite, and follows what I did with RM2 on the rare occasions I had to deal with underwater or aerial combat. There are some pretty basic underwater combat guidelines in Sea Law, but that’s about as complex as I ever wanted to get with it.
    Magic, obviously, plays a role, as it can be used to negate creating issues, ease movement, and even attack. I’d expect it would also come into play in the other environments mentioned, especially some of the stuff in the Elemental Companion.

  2. I’ve had more underwater scenarios than aerial, and no 0-g settings. And honestly, I think I end up reinventing rules each time. Somewhere I have a stack of notes for merpeople and how their civilization works, including what kind of weapons they developed. But for terrestrials suddenly in the water, I think I’ve done something like: swung weapons are at 10% of OB, strung weapons at 20% and ranges cut the same, thrusting weapons at 50%. Hadn’t thought about thrown weapons but if I went broad, I’d say same as swung weapons, and if I went granular I’d allow some differences for, say, javelin and spear as opposed to dagger, axe, or net. Sweeps and throws, useless. Strikes would depend on style or strike type. My merpeople do have aquatic martial arts, buried in those papers.

    For spells, some are easy translations, others not so much. You noted vacuum, and I would be really reluctant to let that work underwater. Water’s 1000x denser than air, and for the same level spell to void that volume would (physics nerding here) mean 1000x the energy/damage as it implodes. I’d say “gas” spells do very little underwater. What would be interesting is thinking up spells the underwater (or aerial) based beings might have that are specifically designed for use against terrestrials.

  3. If you think about it all of the arenas described follow the same rules for movement dependent on two factors. In a vacuum, the resistance is 0 and you increase it from there on depending on what medium you are in (air, water, lava). There is a reason boats are slower than other forms of transport. The other factor is gravity, which sucks! Well, it does if you don’t have enough momentum and uplift to stay aloft. Of course, depending on your world’s interpretation of magic effects, there is, as mentioned, the question of how the uplift forces are applied. I think Jengada is right, if the medium is denser then the power output needs to be higher. We’ve littered SF with high G beings having a higher strength than low G, why not the same concept for atmospheric density? Perhaps Merman (if they can go on land) can throw land dwellers like rag dolls but are unable to cast spells as magic burns out the individual. Heaven help the earthly kingdoms should they discover it is easier above water….

    On the combat side of orientation, attitude, spatial awareness (perception), velocity and momentum. We should be able to rip out the mechanics from any good air/space/underwater combat and bolt them to an RMU chassis surely.

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