Hardness
The hardness trait measures the resistance to force, its ability to take physical stress without showing strain.
note
HX = Size (Number) • H
Hardness also affects your health points by boosting your HX as the hp,max formula shows.
note
hp,max = HX • (1 + M(Health))
Since most biological creatures have a hardness of 1, we usually don't count the hardness. But many vehicles have a hardness of 2 and armoured vehicles have a hardness of 3 or even 4.
If your hardness trait is 2 or higher, you automatically have 2(rst,frc), 2(rst,prc) and 2(rst,sls)