Since WotC were kind enough to post the D20 Modern SRD, I took a look through the vehicles to see how they decided to work them and how close to the T20 system they were.
Answer, not very, but close enough. For all you T20 gearheads, here is a quick system to convert the output of the T20 vehicle design system to D20 Modern vehicles. The table is in the order of the vehicles table. The values are how to calculate the values from T20 vehicles.
Name: From the design
Crew: From the design
Passengers: From the Design
Cargo: Cargo vls divided by 2.
Init: Size Mod.
Maneuver: Init + Agility
Top Speed: Top speed in kph.
Defense: 10 + vehicle size mod.
Hardness: 5 + Armor Rating
HP: Use SI for M size, SI * 0.9 for L size, SI * 0.75 for H size, and SI * 0.5 for G size.
Size: as written.
Purchase DC: Cr * 3 = Cost, convert to DC per the rules.
Restrictrion: Per DM/campaing fiat.
Vehicle size mod is -1 for Large, -2 for Huge, -4 for Gigantic (per D20 rules).
The only thing that has me most confused is the HP. If anyone has a pointer to how to calculate D20 Modern HP for a vehicle, please point it out.
And of course, you can reverse these formulas for a quick T20 vehicle if needed.
Answer, not very, but close enough. For all you T20 gearheads, here is a quick system to convert the output of the T20 vehicle design system to D20 Modern vehicles. The table is in the order of the vehicles table. The values are how to calculate the values from T20 vehicles.
Name: From the design
Crew: From the design
Passengers: From the Design
Cargo: Cargo vls divided by 2.
Init: Size Mod.
Maneuver: Init + Agility
Top Speed: Top speed in kph.
Defense: 10 + vehicle size mod.
Hardness: 5 + Armor Rating
HP: Use SI for M size, SI * 0.9 for L size, SI * 0.75 for H size, and SI * 0.5 for G size.
Size: as written.
Purchase DC: Cr * 3 = Cost, convert to DC per the rules.
Restrictrion: Per DM/campaing fiat.
Vehicle size mod is -1 for Large, -2 for Huge, -4 for Gigantic (per D20 rules).
The only thing that has me most confused is the HP. If anyone has a pointer to how to calculate D20 Modern HP for a vehicle, please point it out.
And of course, you can reverse these formulas for a quick T20 vehicle if needed.