Health Factor (HX)
The health factor is a derived trait representing your physical presence, and is usually equal to your size multiplied by your hardness (H).
As most sophonts have a hardness of 1 and are of medium (4) size, most sophonts start the game with HX = 4.
Maximum Health Points (hp,max)
Your HX affects your maximum health points (hp,max), which are found by:
note
hp,max = HX • (1 + M(Health))
That is, add 1 to your Health modifier, and multiply the result by your HX.
Health Point Recovery (hp/r)
Your HX also affects the rate at which your health points recover after a rest (hp/r), which is found by:
note
hp/r = ½ • HX + M(Health)
That is, halve your HX and add your Health modifier.