It does rather seem a little peculiar that despite having such good (for a core book) spaceship construction rules, that the Starfinder book lacks similar rules for vehicles. Certainly, the rules that are created for spaceships are fairly easily adaptable to vehicles.
To give us some kind of scale for comparison, a Colossal Vehicle is equivalent in size to a Medium vehicle. A Gargantuan Vehicle to a small starship and a Huge vehicle to a Tiny starship.
From that you can work out some baselines, keeping in mind that Starship scale weapons do x10 damage at person scale (at which vehicles operate) and are similarly tougher – generally treated as objects.
Looking at the example vehicles we can see that a Medium vehicle is considered a bike, a Large vehicle a car or buggy and a Huge vehicle a truck. From there we can surmise that a Gargantuan vehicle is equivalent to a main battle tank and that a Colossal vehicle would be the equivalent of a land-carrier or land-train (though that might be better done as individual, modular vehicles). Anything below medium size probably isn’t viable as a vehicle, though hoverboards and similar might be served in such a way, they’re probably better off considered as equipment.
Vehicles created this way are much hardier than those found in the book, but that seemed more fitting somehow.
Build Points
Build Points would probably still go by tier, halved, rounding down. though this would need some testing to make sure it didn’t make things absurd, this would also set the ‘level’ of the vehicle as gear, so for most militaries etc the upper limit would be Level 6, with penalties as previously discussed when talking about weapons.
Base Frame
Land-Carrier
- Size: Colossal
- Manoeuvrability: Clumsy, -2 Piloting, Turn 4
- HP: 550/Increment 100, Base Hardness: 20
- Mounts: Forward Arc (1 Starship Heavy, 1 Starship Light), Aft Arc (1 Starship Light), Turret (2 Starship Light)
- Expansion Bays: 5
- Minimum Crew: 1, Maximum Crew: 6
- Cost: 15
Main Battle Tank
- Size: Gargantuan
- Manoeuvrability: Poor, -1 Piloting, Turn 3
- HP: 350/Increment 50, Base Hardness: 15
- Mounts: Turret (1 Starship Light), Port Arc (1 Personnel Heavy), Starboard Arc (1 Personnel Heavy).
- Expansion Bays: 3
- Minimum Crew 1: Maximum Crew: 4
- Cost: 10
Truck
- Size: Huge
- Manoeuvrability: Average, +0 Piloting, Turn 2
- HP: 200/Increment 50, Base Hardness 10
- Mounts: Forward Arc (1 Starship Light), Aft Arc (1 Starship Light)
- Expansion Bays: 1
- Minimum Crew 1: Maximum Crew: 2
- Cost: 8
Pick-Up
- Size: Large
- Manoeuverability: Good, +1 Piloting, Turn 1
- HP 50/Increment 25, Base Hardness 5
- Mounts: Turret (1 Personnel Heavy).
- Expansion Bays: 0
- Cost: 4
Motorcycle
- Size: Medium
- Manoeuvrability: Perfect +2 Piloting, Turn 0
- HP 15/Increment 5, Base Hardness 0
- Mounts: None.
- Expansion Bays: 0
- Cost: 2
Fitting Out
Powerplant-wise we’re limited to something like…
- Colossal Vehicles being able to fit up to Nova Ultra.
- Gargantuan Vehicles being able to fit up to Pulse Prismatic.
- Huge Vehicles being able to fit up to Pulse Blue.
- Large Vehicles being able to fit up to Pulse White.
- Medium Vehicles being able to fit up to Micron Light only.
We could also add some smaller powerplants beneath that level, say…
- Micron Superlight PCU 30, Cost 2
- Micron Ultralight PCU 15, Cost 1
Regarding speed, aerial and hover vehicles could retain the speed equivalent to the thrusters (and the power requirements). Land/Water vehicles would reduce the speed by 2 and the cost by 1. They should probably, also, be limited to a maximum speed of 6 (After modification).
We’re also going to need smaller drive-trains for smaller vehicles.
- Colossal Vehicles can use M# Thrusters.
- Gargantuan Vehicles can use S# Thrusters
- Huge Vehicles can use T# Thrusters.
- Large Vehicles can use LV# Thrusters
- Medium Vehicles can use MV# Thrusters.
- LV4 Size: Large Vehicle, Speed: 4 (20ft), Piloting Modifier +1, PCU 15, Cost 2
- LV6 Size: Large Vehicle, Speed: 6 (30ft), Piloting Modifier +0, PCU 20, Cost 3
- LV8 Size: Large Vehicle, Speed 8 (40 ft), Piloting Modifier -1, PCU 25, Cost 4
- MV4 Size: Medium Vehicle, Speed: 4 (20 ft), Piloting Modifier +1, PCE 10, Cost 1
- MV6 Size: Medium Vehicle, Speed: 6 (30 ft), Piloting Modifier +0, PCE 15, Cost 2
- MV8 Size: Medium Vehicle, Speed: 8 (40 ft), Piloting Modifier -1, PCE 20, Cost 3.
Armour
This appears to be usable as is, but you should be able to decrease from the baseline to get points back and, similarly, to buy up (or sell down) hardness. Sizes would be considered:
- Colossal: 2
- Gargantuan: 1
- Huge: 0.75
- Large: 0.5
- Medium: 0.25
(Rounded up)
AC and TL modifiers would be the same – just at personnel scale – and you could trade up to 10% from EAC to KAC or vice versa after buying up armour.
Computers
Aren’t Essential
Crew Quarters
Generally aren’t necessary
Countermeasures
Depends on the vehicle
Drift Engines
Unnecessary
Expansion Bays
For vehicles large enough, these are viable. For smaller vehicles, more basic options should be purchasable.
Security Systems
Depends on the vehicle.
Sensors
Depends on the vehicle and its role.
Weapons
A slot can fit a weapon of that size or smaller. Vehicle mounts will typically hold Starship scale weapons of light and sometimes heavy size (don’t forget to scale the damage) or personnel scale heavy or two-handed weapons. Anything else will usually be carried by the driver or crew.
Shields
Some vehicles may well have shields but don’t forget to scale these if you do add them. Vehicles of Medium size could also mount personnel scale shields.
Example
For shits and giggles, lets make one of the monobikes from the anime Venus Wars. This is a grotesquely overpowered attack motorcycle, intended to be a tank-killer and driven (in theory) by an elite force.
So we’re looking at a tier 6 vehicle, 77 build points with one HP increase.
It’s a medium vehicle.
It needs to be overpowered for its antitank role, so we give it the full Micron Light.
It needs to be fast for its role, so MV8 Size: Medium Vehicle, Speed: 6 (30 ft), Piloting Modifier -1, PCE 20.
This bike is armoured, but it is still a bike and does still need to be fast. The best armour we could give it would be MK8 at a cost of 4 points.
We can’t increase its hardness, given that a typical conversion would by 5 points of AC to one point of hardness and this would slow it down.
As a military bike it will have a hardened combat computer of some sort to process sensors and assist with diagnostics. We fit a Mk1 Mononode.
We’ll give it Anti-Hacking security, Biometric Locks, Computer Countermeasures and a self-destruct option.
Motorcycles normally don’t have any weapon mounts, but we need to cram one on here. 3 BP gets us a Light Starship front arc weapon mount and we also buy a heavy (personnel weapon mount) for 2 BP.
We slam in a High Explosive Missile Launcher for its anti-tank role and a Tactical X-Gen machinegun.
Given all these points remaining and its antitank role, as well as its remaining power we can slap in Mk 8 Defensive countermeasures, providing +8 AC against tracking weapons. We can also give it advanced long-range sensors.
At the end of all that we still have 14 points left.
The GM, being a generous sort, allows the biker to also purchase increased hardness at the same cost as level 5 armour. That drops us to 12 points, makes the TL -2 (both types of armour).
With those points left-over the GM rules that the bike has a survival and medical kit on board and a killer paint job.
NB: Given the example of design, I think we would need to reduce the point allotment by more than half, perhaps 1/3rd, rounding down. This would force budget economy decisions. As such this bike would have to be redesigned using 51 points instead.