Saturday, July 14, 2018

Vectored (i.e., Zero Gee) Combat in Tachyon Squadron

One of the things I've wanted to do for years was adapt Jovian Chronicles to Fate Core. For those who don't know Jovian Chronicles is a somewhat "firm" science fiction game with the exception of giant robots. There are in setting justifications as to why there are mecha (called exo-armors), but it's all well and good because GIANT ROBOTS. But Jovian Chronicles' space combat, which was bootstrapped from the Heavy Gear miniatures rules, has always been a bear. It used a vector combat system that keeps track of velocity, acceleration and the direction of thrust, on a hex map. I've only used it only a couple times before abandoning it in favor of hand waving position and maneuvering with die rolls.

Jovian Chronicles immediately came to mind when I heard about Tachyon Squadron, and I wasn't disappointed. The maneuver chart is a great mechanic for not just space combat, but aerial and maybe even vehicle combat in general. The only hiccup I had in relation to Jovian Chronicles is that swooping space opera-style fighter combat doesn't really match the tone of the setting (disregarding the existence of the giant robots). So I started to think about what minor tweaks could be made to allow a little more of the "there's no up and down" nature of space combat.

The first act was to bend the maneuver chart into a circle, for no other reason than it's space. I placed a line down the center to divide the two halves, but the numbering just goes left to right. Since most space combat, even in Jovian Chronicles, revolves around ships, asteroids, stations, planets, etc. I decided to put the Special slot at the center. Undetected gets its own box, and I have some embryonic ideas of introducing another slot or two to represent specific circumstances (or subdivide the Special slot, I'm not sure yet).

In a very general sense, the bands can be seen to represent the relative velocity of the combatants - a higher band means higher relative velocity. Degradation can be taken to represent the tendency for the combatants to "settle" on lower differences in their relative velocity. It all still boils down to who has the advantage, and would work the same way as the default maneuver chart.

But there some concepts from Tachyon Space that don't quite fit Newtonian space combat, such as some of the actions (like Desperate Attack and On Their Tail). Some cases might just need a rename or slight tweaks to how they work. For example, I'm thinking On Their Tail would be renamed Intercept, which represents that the pursuer has vectors that are difficult for the defender to avoid. So far, it would be pretty easy.

Before getting into how to represent being able to freely change facing in a zero-gee environment, it's probably best to explain the justification for exo-armors being such good space fighters in the Jovian Chronicles setting. Exo-armor cockpits are basically spheres, with an exo-skeleton like control chair called a linear frame suspended in the middle on an arm. The pilot straps into the frame, and uses their body movements to translate into movement of the exo-armor. This is supposed to allow pilots to transfer changes in their own position and center of mass to the exo-armor's gyroscopes and limbs, making them more maneuverable and efficient than a traditional space fighter. Plus, manipulator mounted weapons are effectively on gimbals, giving them an increased field of fire. In the end the exo-armor has a flexible form that can make precise changes in vector with minimal expenditure of reaction mass, and weaponry with variable fields of fire (Disclaimer: these are the in-setting reasons for things working the way they do, not necessarily how it would be in reality).

With this in mind, reaction mass could be leveraged as the means to allow fighters to attack higher bands. The idea I have is that each ship has a reaction mass track with some amount of boxes (maybe 10 or 20, they could definitely vary by ship). Some actions - degradation and Tactical Refocus for example -might not no need to tick off remass; others might require a box be ticked off. So when a ship decides to "punch up" to attack a higher band, the pilot needs to tick off one or more remass boxes. I'm still not sure the number, but I'm thinking it would be the difference in the bands. Using remass will also open up the possibility of stunts that can lower the remass of actions, or require remass to perform.

I definitely need to continue pecking at this, and then get some playtesting down...but so far I'm liking it. Next up I need to write up a few exo-armors Tachyon Squadron-style.