Spaceships (to go with some of my other brew maybe sometime). Just a concept thing at the moment.
Subsystems do things. They're usually energy receptacles.
Things tax the subsystems that they are involved with. A ship carrying lots of cargo taxes its engines, Firing weapon modules taxes the weapon subsystem, etc.
Each subsystem has a taxation threshold that affects how badly it can be taxed before it fails.
- Threshold N (where N>=2): N taxations of a given level are count as one taxation of the next higher level.
- Threshold 1: As a threshold 2 subsystem, but each taxation counts as 1 level higher.
- Threshold 0: As a threshold 2 subsystem, but each taxation counts as 2 levels higher. As a result, anything more than a single light taxation is overwhelming.
Taxations come in multiple (enumerated) levels. Only the highest level counts when determining penalties and other effects on the subsystem.
- 1: Light. Standard operating levels. No penalties.
- 2: Moderate. Higher operating levels, but still within expected parameters. Some subsystems may not work as efficiently (see the subsystem's description).
- 3: Heavy. The limit of acceptable operating levels. Most subsystems will not work as efficiently (see the subsystem's description).
- 4: Overwhelming. A subsystem that is overwhelmingly taxed fails safely. It simply stops working, but no real damage is done and the subsystem can reinstate its normal functions once the stresses on it are lessened. Life support may be unable to supply fresh oxygen as fast as it is being consumed, or engines may just shut down. The subsystem is disabled for as long as it is overwhelmingly taxed, and for 1 round thereafter. Nondestructive taxations never increase beyond overwhelming.
- 5: Critical. A subsystem that is critically taxed fails destructively. Not only does it cease functioning, but it will require repairs to work again even after the taxations are lessened or removed. Taxations never increase beyond critical.
Some example subsystems and taxations
Engines let the ship move. They also provide a Strength score to the ship, which, as an immobile hunk of metal, would otherwise no more be able to interact with its environment than any other piece of terrain.
Moderately taxed engines impose the same penalties as carrying a medium load on the ship (~2/3 speed, ACP, etc.). Its maneuverability also drops one category (minimum clumsy).
Heavily taxed engines impose the same penalties as carrying a heavy load on the ship (~2/3 speed, x3 run speed, ACP, etc.). Its maneuverability also drops two categories (minimum clumsy).
Cargo weight taxes the ship's engines. A light load lightly taxes the subsystem, a medium load moderately taxes it, and a heavy load heavily taxes it. Move than the ship's maximum load overwhelmingly taxes the engines.
Life Support provides a breathable atmosphere and generally keeps you from dying a horrible death from asphyxiation. It also keeps your water recycled and your food fresh, but those tend to be less urgent matters.
Each breathing human (or equivalent Medium-sized creature) lightly taxes the life support subsystem. Smaller and larger creatures that consume more or less oxygen (or whatever the relevant atmospheric components are) than a normal human counts as fewer or greater numbers of light taxations. Fires fall under this category, too.
Open airlocks, hull breaches, and other losses of containment tax the life support system. Larger breaches tax more than smaller ones, duh.
Keeps doors closed between compartments. Or opens them. Ditto for airlocks.
It's a DC whatever Str check to pry open a door. Success opens the door and also heavily taxes the door control subsystem. Failure by 5 or less still moderately taxes the door control system. Enough boarders breaking down doors can thus effectively disable the door control over the entire ship.
Sample ship: The Kestrel
Colossal 3 Construct (mecha)
HD: 60d10+180 (450 hp)
AC: 7 (+1 Dex, -24 size, +20 natural), touch -13, flat 6
Movement: Fly 600' (average)
Compartments: 1x Colossal, 4x Large, 8x Medium
Subsystems and Thresholds: Autopilot 1, Door Control 1, Engines 3, Life Support 3, Sensors 1, Shielding 4, Weapons 4
Attacks: Burst Laser +31 ranged (8d6), or Missile +31 ranged (12d8)
Full Attack: Burst Laser +31/+26/+21/+16 ranged (8d6) and Leto Missile +26 ranged (12d8)
Special Attacks: ...
Special Defenses: Energy Shield 50/10, Hardness 10
Saves: Fort +23, Ref +21, Will +20
Str -- (31), Dex -- (13), Con -- (16), Int --, Wis -- (10), Cha -- (10)
-24 size mod, -32 for grapple, etc.
Some of the things in here have been mentioned before in my other 'brew. Energy Shield is a Power of Cybernetics ability (absorbs damage from external sources, up to a total amount of the number before the slash, regenerates the number after the slash each round). Compartments were described in an earlier draft I had here for doing mechas.
Just a template to get ideas and concepts out. Also, I've been playing too much FTL lately.