Approximating High-Tech and Ultra-Tech with Spaceships

[Michael Thayne]

So I've been fiddling with some numbers, trying to figure out how to get more mileage out of Spaceships at least until Vehicles 4e comes along. After struggling a bit, I think you can get a pretty good approximating of a lot of vehicle and weapon stats from other books if you use the following design switches.

Tank Hull: This is a second-order option that builds on the "Armor by Facing" rules from Pyramid #3/34. Vehicles with this option are built like tanks, literally, with a relatively narrow head-on profile, and a much broader overhead profile. This means that front and rear DR is doubled, but top and underside DR is halved.

Surface Combat Ammunition: Ammunition for conventional guns and launchers can be designated "surface combat", this means it only costs $20,000 per ton, but is limited to point-blank range. Such ammunition can be given shaped-charge warheads, which to half normal damage but with Armor Divisor (10).

Example: Zhukov-class Main Battle Tank is built as a TL7, SM +5 vehicle with spaces allocated as follows:

1 Major Battery
1 Tracked Drivetrain
2 Control Room
2 Internal Combustion Engine
14 Light Alloy

It cost $500,000 and weighs 30 tons. It has the design features Tank Hull and NBC Filters Only, and generally carries surface combat ammunition. The Armor and Volume rules reduce its SM to +4, and give it 112 dDR to distribute among its six facings. We'll distribute the DR like so:

* Front: 98 dDR (counts as 49 dDR)
* Sides: 14 dDR each
* Rear: 14 dDR (counts as 7 dDR)
* Top: 8 dDR (counts as 16 dDR)
* Underside: 6 dDR (counts as 12 dDR)

Its cannon does 3dx5(2) dDamage, or 7d(10) dDamage with shaped charge warheads. All these stats compare pretty favorably to the T-72, especially given that it weighs only 2/3 of what the T-72 weighs.

Thoughts? Are there other significant gaps in the Spaceships rules for emulating other real-world vehicles (I think these rules tweaks are enough to emulate fighter jets pretty well, but I haven't checked).

[Lord Azagthoth]

Do you add extra weight for vehicles? For example, an SM+4 tank weighs as much as a SM+5 spaceship?

Because I was always thinking that spaceships are built on lighter weight hulls than planetary-based vehicles, especially when they are wheeled or tracked.

[RyanW]

Originally Posted by Lord Azagthoth

Do you add extra weight for vehicles? For example, an SM+4 tank weighs as much as a SM+5 spaceship?

Because I was always thinking that spaceships are built on lighter weight hulls than planetary-based vehicles, especially when they are wheeled or tracked.

For that, you just need to use the armor density rules from one of the Pyramid articles. When dealing with heavily armored vehicles, general SM does not equal Spaceships SM. Since the Spaceships system is built heavily mass, you should subtract SM rather than add weight.

[Lord Azagthoth]

I don't have Pyramid. Happen to know in which issue the article is?

[Michael Thayne]

Originally Posted by Lord Azagthoth

I don't have Pyramid. Happen to know in which issue the article is?

#3/34, "Alternate Spaceships", also has the "Armor by Facing" rules, rules for "ships" with tank treads, and similar useful things.

[Lord Azagthoth]

Tnx Michael.