3e Vehicle HP conversion

[Joseph Paul]

The RoS thread got me thinking about how to deal with the differences in 3e and 4e regarding vehicles and their destruction.

In Robots HP is figured on the size of the subassembly and then modified for the strength of the frame. There does not seem to be a total HP stat of the machine. Destruction is piecemeal, a location at a time.

4e has a Total HP which is then broken out as fractions of the total for subassemblies. Damage to the vehicle is tallied against HP in any location hit and the effects derive from that.

So I would like to hear how people have dealt with this. Do you add up all of the 3e HP into a Total HP and redistribute according to the 4e scheme? Or do something else?

[Fred Brackin]

Originally Posted by Joseph Paul

So I would like to hear how people have dealt with this. Do you add up all of the 3e HP into a Total HP and redistribute according to the 4e scheme? Or do something else?

To the best of my understanding the only accurate way to figure HP for an object is based on total weight using the charts in Basic. Robots should be bought as Unliving ad not Homogenous. There is no conversion from 3e HP numbers, either added together or separate.

Now something bought as a _character_ with cp (such as an Ally) has as many HP as were paid for. If you want it to be realistic try and keep it in line with the weight-based numbers.

[Joseph Paul]

So the Juggernaught in RoS goes from just the body having 3600 HP to the whole vehicle having 200 HP? But it keeps its Laminate DR of 1200/(2400 on some facings)? And the Laminate has the advantage of doubling DR vs HEAT? Or do people replace that with a level of Hardened?

[Fred Brackin]

Originally Posted by Joseph Paul

So the Juggernaught in RoS goes from just the body having 3600 HP to the whole vehicle having 200 HP? But it keeps its Laminate DR of 1200/(2400 on some facings)? And the Laminate has the advantage of doubling DR vs HEAT? Or do people replace that with a level of Hardened?

Probably yes on the HP. There was a deliberate, major shift in how HP were calculated between 3e and 4e.

Armor and weapons damage in HT was largely unchanged between editions. UT saw some trading of energy weapon damage for higher divisors.

Laminate is 2x v. HEAT in HT and elsewhere. A level of Hardened might make sense for things with DU in their composite armor. That would keep DU v. DU the same as steel v. steel. You could extend that to 2 levels for Hyperdense.

I think it makes sense but it's only my House Rule and certainly not official.

[RyanW]

Originally Posted by Joseph Paul

So the Juggernaught in RoS goes from just the body having 3600 HP to the whole vehicle having 200 HP? But it keeps its Laminate DR of 1200/(2400 on some facings)? And the Laminate has the advantage of doubling DR vs HEAT? Or do people replace that with a level of Hardened?

3e Vehicles HP were based on surface area (scaling with the 2/3 power of mass), while 4e HP are based on linear measure (scaling with the 1/3 power of mass). If I were trying to convert, I would use sqrt(10*HP) which would put it at 190 HP.

Two ways to do laminate armor:
DR (Hardened: Only versus shaped charges) [a limited enhancement]
DR + DR (Only versus shape charges)