Balancing HP

[Anthony]

I would fix it by having 'mass' be a separate attribute and removing HP from the collision damage formula; things have whatever hp gives them the appropriate toughness.

[Sorenant]

HP is related to Mass, but not exclusively. In characters, it's represents mainly how much damage it can take before dying/stop working, with mass being a secondary trait.
A golem might be homogeneous, but it doesn't necessarily will have 4 times the HP of a living creature of same size, because the magic animating it might require the body to not be too damaged to work. It's often represented by Fragile (Unnatural) but it can also come coupled with lower HP (eg DF Golem).

[NineDaysDead]

Old thread:

Originally Posted by David L Pulver

This doesn’t explain anything, since this was never in question. The question is “why do Unliving, Homogenous things etc have more HP than living things of the same weight?” not “What are HP?”

*Living thing: vulnerable to system failure from destruction of a small part. There are multiple internal organs any of which if damaged or destroyed will cause incapacitation or death, not to mention pain, shock, etc.
* Unliving thing: Less vulnerable. An airplane or car can be shot full of holes, but still function. Tear the doors of a car and it will still work fine. Tear the skin off a person and he's moaning in pain. Tear the skin off a zombie and he's a skeleton and still coming... Or think Terminator (arnie-model).
* Homogenous thing. You can keep smashing it to bits, but it doesn't matter until you've structurally destroyed it. A block of wood. A golem. A raft. Or think a terminator (liquid metal model) .

Now, there are also *damage modifiers* for each type of damage. So burning damage is fully effective vs. all three types as it affects a larger surface area, but piercing damage is most effectively against living things, because the damage area is relatively small. You are perhaps arguing for a big damage divisor. But a big damage divisor (homogenous takes x1/4 damage from everything) not only loses the flavor - the current system encourages you to choose your weapons and deal with zombies with axes and flamethrowers - but also is essentially identical to giving 4x HP anyway.

So, the system simply recommends that anything that is homogenous have 4x HP and anything unliving have 2x HP and then piles on additional divisors as necessary.

[Fred Brackin]

Originally Posted by Curmudgeon

I think you're agreeing with me about weight and HP. The OP has offered his formulas specifically to apply to characters.

I was agreeing with you only in regard to the part I quoted. I was ignoring the part I didn't quote.

I would agree more generally with Anthony that if Gurps is going to ahve a realistic take on character mass it needs to have a "mass" stat and it should stop trying to use ST and/or HP for that purpose.

If you do try and use HP as a deteminer of mass in the "collision" formulas no human should have more than about 14 HP. This would harmonize with ST15(18 Arm) gorillas and ST 20 grizzly bears but would limit chargen in a dull fashion.

[Rupert]

Originally Posted by NineDaysDead

Three 150lb beings one living, one Unliving and one Homogeneous all have the same mass, so should be treated the same for things like knockback, falls, and slams etc. However they all have different HP. Living being just takes HP 10, the others take HP 10, and extra HP with the Massless modifier.

When it comes to knockback, they already get this effect, because it's based on ST, not HP, and ST isn't doubled (or quadrupled) for being Unliving (or Homogeneous).

[AlexanderHowl]

I am not saying that HP should be multiplied with taking the advantages, just that characters should take the appropriate level of HP with their mass. A 125 lb Diffuse superhuman should probably take HP 40 or else justify their lower HP with lower mass (they are actually a nanoswarm that masses only 2 lbs that just appears to mass 125 lbs). Otherwise, you get some rather weird characters, such as character that is less durable than a similar weight of jello, despite both being 125 lbs of diffuse matter.

[NineDaysDead]

Originally Posted by Rupert

When it comes to knockback, they already get this effect, because it's based on ST, not HP, and ST isn't doubled (or quadrupled) for being Unliving (or Homogeneous).

It's based on HP when not resisting, basic page 378:

If the target has no ST score at all (like a wall), or is not resisting, use its HP instead.

[whswhs]

Originally Posted by NineDaysDead

It's based on HP when not resisting, basic page 378:

GURPS is already violating the physics of mass with its rules for knockback. The incoming projectile has a mass and a velocity; their product is momentum. Knockback for a perfectly elastic collision ought to have a speed of 2mV/M; for a perfectly inelastic collision it ought to be mV/(m+M). But the GURPS formula makes it proportional to speed (v) times HP (proportional to m^(1/3)). That's going to have massive objects cause far less knockback than they ought to, and low mass objects far more.

If you want correct physics, you need to throw out those rules and do some actual physics. If you're willing to consider the current rules close enough for gaming, then I don't see the point of worrying about HP changing to reflect the differential toughness of organisms, machines, and masses.

[Rupert]

Originally Posted by NineDaysDead

It's based on HP when not resisting, basic page 378:

Which results in a lot of PCs being harder to knockback when they're not resisting than when they are.

[NineDaysDead]

Originally Posted by Rupert

Which results in a lot of PCs being harder to knockback when they're not resisting than when they are.

If your HP are higher than your ST, you just never resist, and take the better result.