[Technical Solutions] Mass combat aboard Spaceships

[vicky_molokh]

Greetings, all!

Inspired by a short story about a Rogue Trader game, I decided to start up a thread about using Mass Combat for operations on a spaceship - primarily boarding actions. It'll take the form of incomplete notes, and I if you like what you read, you should try contributing by fixes and additions (since I'm not sure I'll treat the project seriously - this is mostly a side thought of mine). Here goes.

SPECIAL CLASS (CLASS)
Air, Artillery, Cavalry and Naval units should be unavailable or irrelevant in most boarding actions. Unless you're actually fighting on the surface of a giant space station (e.g. moon-sized), in which case just use normal Mass Combat rules.

Mobility: Water Mobility is likewise inappropriate, unless the boarded ship belongs to an Aquatic race. If this is the case, units with Water mobility use full TS, Marine units use half TS, and units incapable of water movement cannot participate.

OPTIONAL FEATURES
Airborne + Sealed allow space troopers to deploy using space flight packs or other contraptions. They still need a method for breaking into the enemy craft. This may be done using specialized boarding craft, or using Engineers, Armor etc.
G-trained: G-trained represents troops being trained to act under a gravity different from their own. This Feature can be of two types: Freefall and G-Experience. Freefall represents troops trained in zero/micro-gravity combat, while G-Experience halves the TS reduction for acting under non-native gravity (but not for Microgravity!). Note that G-Trained (G-Experience) also assumes minor additional equipment used for improving adaptation to a different gravity and/or modest levels of Improved G-Tolarance on the part of actual soldiers. Either Feature costs +20%.

CAMPAIGNING
A boarding action against an air-breathing (or non-breathing) race allows units with Land mobility to participate. A boarding action against an aquatic race needs units with Water mobility and/or the Marine feature (see above).

Posture of Encamped Forces
Unless the boarding action was a complete surprise, treat the defending side as Bunkered.

The Reconnaissance Contest
Ignore modifiers except the +3 for being Bunkered. Treat Terrain Rating as Plains if the ship has adequate security systems, Built-Up Areas otherwise.

INITIAL INTELLIGENCE
The boarding party normally receives information as per the Encounter Battle, unless one of the ships in their fleet successfully used some sort of Bioscanner or equivalent on the boarded ship. The defending party receives information as per Pitched Battle. On the second round of battle this doesn't change. Only give the boarding party more info if they perform a scan, find a crew manifest etc.

Special Class Superiority
Inappropriate Classes (see above) also do not contribute to Special Class Superiority if they are present for some reason.
Engineering Superiority always applies.

DEFENSE BONUS
The defending ship normally has a Defense Bonus of +5. If a Defense Network system is included on the ship (representing space and mass dedicated security stations, hidden cameras, turrets, defensive tunnel networks etc.), then increase the DB to TL+5.

FIGHTING THE BATTLE
Retreat Strategies may only be chosen by a force with ready shuttles, escape capsules etc.
SPECIAL CASES:
Decompression and vacuum: the party in control of the ship may opt to purge the air from some or all compartments. If it is done before the battle partially, then non-Sealed elements have their TS halved; normally they are bunkered in sealed rooms. If it is done before the battle fully, only Sealed elements may board the ship; non-Sealed defenders must be bunkered in small rooms or given cheap emergency spacesuits in advance to avoid casualties (while they're prepared for decompression, their TS is halved; after it, treat them as 'temporary casualties' which will immediately become combat-capable as soon as the air is available). If this is done during battle (partially or fully), then 50%/100% of the unsealed units become casualties; this can be prevented by Engineers - an Engineer unit may save up to 5× it TS worth of other units; these Casualties can not be halved after combat as per Hold the Field!). Purging air during battle if you have unprepared unsealed units should only be used in combination with Desperate Strategy, unless the commanding officers are completely ruthless.
Different Gravity: Units in zero/microgravity have their TS halved unless they have the G-trained (Freefall) optional feature. Units acting in non-native gravity have their TS reduced by 10% per full G-increment away from their native gravity; G-Trained (G-Experience) halves it to -5% per increment. Notice that in setting with no gravity generators, it is highly recommended that all space marines be G-Trained.

Comments? Additions? Corrections?
Thanks in advance!

[sir_pudding]

Originally Posted by vicky_molokh

Mobility: Water Mobility is likewise inappropriate.

Maybe not. What if the targets are aquatic?

There probably ought to be zero-G mobility, too.

[vicky_molokh]

Originally Posted by sir_pudding

Maybe not. What if the targets are aquatic?

There probably ought to be zero-G mobility, too.

Good point about aquatic races (like Trillarians or the Orz). Wouldn't want a zero-G mobility, as Air mobility basically does that.

I was wondering whether 'Spaceship' is a valid Terrain specialization (as in, cramped corridors and the possibility of either absent, or magnetically emulated, gravity).

Edited. Thank you for your suggestions.

[sir_pudding]

Originally Posted by vicky_molokh

Wouldn't want a zero-G mobility, as Air mobility basically does that.

I wasn't thinking flight packs but rather troops trained for microgravity mobility, (relevant in settings that usually feature artificial gravity).

I was wondering whether 'Spaceship' is a valid Terrain specialization (as in, cramped corridors and the possibility of either absent, or magnetically emulated, gravity).

I don't see why not. Some settings definitely feature specialized boarding troops.

[vicky_molokh]

Originally Posted by sir_pudding

I wasn't thinking flight packs but rather troops trained for microgravity mobility, (relevant in settings that usually feature artificial gravity).

I don't see why not. Some settings definitely feature specialized boarding troops.

Seems like both might indeed fall under the umbrella of 'Space troopers'. But that would effectively halve the TS of non-Space units (or double that of Space units - whatever). Sounds pretty harsh.

[Langy]

Originally Posted by vicky_molokh

Seems like both might indeed fall under the umbrella of 'Space troopers'. But that would effectively halve the TS of non-Space units (or double that of Space units - whatever). Sounds pretty harsh.

Sounds pretty realistic, at least for the microgravity bit. Someone in microgravity with no microgravity combat training isn't likely to be anywhere near as combat-capable as someone with actual training in microgravity combat. Just moving around would probably be very difficult, much less firing a non-recoilless weapon.