4E's hit point philosophy

[Langy]

Originally Posted by sir_pudding

How would ever get that far? Just give the NPC seamen +.25 more Speed than the PCs and it will decades before anybody gets to roll anything. "Able Seamen Jones takes a Ready and assists with setting the sail, Able Seaman Henry takes a Ready and assists with setting the sail, Able Seamen Johnson takes a Ready..."
Who does?

If you say naval combat is really outside the scale of GURPS combat, point out that you can't actually game out a two hour naval battle in ten square miles with hundreds of people with individual one second turns in 1 inch = 1 yd scale and they still want to game it out with the regular combat system you probably should get more players.

Why would you be using individual one-second turns? The rules for vehicle combat don't use them, either in Spaceships or the ones in Action.

[lwcamp]

Originally Posted by hal

Hello Folks,
As I drove into work recently, my mind wandered on the topic of why 4E hit point rules leave me so dis-satisfied.

My mind went on the road or train of thought that started with "Why is it that hit points scale with the cube of the weight" but then doesn't follow known physics when it comes to reality?

Cube root scaling gives relatively good scaling as far as the ability of individual blows to cause damage. The problem comes when you try to add up HP damage from separate wounds. There are a number of ways to handle this:

(1) Do not accumulate HP of damage. Only use the injury caused to determine bleeding, stunning, knockdown, major wounds, and so on. This has the obvious disadvantage that you can never chop down a large tree with an axe, houses never burn down, and so on.

(2) Quadratic HP (QHP). All injury thresholds (major wounds, roll for unconsciousness, etc) are found by taking the RAW value and squaring them (so 5 points for a major wound and 10 for starting unconsciousness rolls RAW becomes 25 and 100, respectively). Square all rolled damage, and subtract the square of the DR of any armor in the way. For injury, multiply the basic damage squared by the square of the wound multiple (i.e., 0.25 for Pi-; 1 for Pi, cr, or tox, or cor; ~2 for Pi+ or cut; 4 for Pi++ or imp). Accumulate only the squared injury. For example, if Our Hero with 12 HP suffers crushing wounds with damage rolls of 3, 4, 7, and 3, we would subtract 9, 12, 49, and 9 from his QHP of 144, leaving him with 65 QHP. He will suffer a major wound, but is otherwise not in danger of passing out like he would be with linear HP.

QHP has two advantages - it is a more realistic representation of armor penetration for most weapons, and avoids unrealisticly rapid accumulation of injury. QHP scales as an area, which is justifiable since many forms of damage are proportional to an area (severity of burns depends on area of skin affected, breaking a structural element like a bone or entire limb is proportional to the cross sectional area of the element, injury from a penetrating wound is reasonably modeled as its depth times its width).

(3) Cubic HP. If QHP still accumulates injury too fast, you can cube HP instead. This simulates your boiling away a volume of water example.

(4) Various house rules, such as http://panoptesv.com/RPGs/HouseRules/wounds.html .

Luke

[DouglasCole]

Originally Posted by lwcamp

Cube root scaling gives relatively good scaling as far as the ability of individual blows to cause damage. The problem comes when you try to add up HP damage from separate wounds. There are a number of ways to handle this:

(1) Do not accumulate HP of damage. Only use the injury caused to determine bleeding, stunning, knockdown, major wounds, and so on. This has the obvious disadvantage that you can never chop down a large tree with an axe, houses never burn down, and so on.

There's a solution to this one that's part of an article I'm polishing. If a blow is large enough, lower the HT of the object you're rolling against. That will spiral and eventually fail badly enough to fell the tree, house, etc.

That may well be in your linked house rules; it's not terribly odd for GURPS. But there's more there, I think.

[Pmandrekar]

Originally Posted by hal

If all we're supposed to view GURPS as, is a game that has no real need to stick to any level of realism, then why are we bothering to create formulas for gun damage based upon actual scientific principles?

I have to speak up, since I've been a playtester and contributor to several GURPS Supplements while using and applying my scientific training and background to bring the level of realism up in those books.

1) We do have to strike a balance between playability and the underlying science. One of the continued problems that non GURPS players have with the system is that it is too realistic, and thus too easy for characters to die.

2) One of the reasons that players do like GURPS is that it folds in more of that science than other systems. That's for certain. My gaming group currently consists of a PhD Raman Spectroscopist, PhD nuclear chemist, PhD in Engineering (I think) who writes medical software, another guy who writes medical software, a BS level oceanographer, and a guy who assembles particle accelerators for a living. Oh, and I have a MS in Genetics, I've been well-known in Forensic DNA circles for about a decade now. In all due fairness, it may not be a science textbook (but then, how much fun would a science text book be? I've got tons of 'em, and I still use my GURPS Books).

3) When any game, TV series, movie wanders into an area of science where we have expertise, especially deep expertise, it does become painful to see how far off of our understood reality it can be. I cannot watch "CSI" for this reason, even though some of the products that I've designed have actually been featured on those shows. Too painful. Makes my science brain itch with the hurty.

So, yeah. It's a game.... and there's nothing wrong with that.

-P

[lwcamp]

Originally Posted by DouglasCole

There's a solution to this one that's part of an article I'm polishing. If a blow is large enough, lower the HT of the object you're rolling against. That will spiral and eventually fail badly enough to fell the tree, house, etc.

I am curious how you implement this. Suppose I have ST 12 and a greataxe (1d+5 cut). I am trying to fell a tree with HP 100. My maximum damage is 16 (or a bit higher if I have the Forced Entry skill). How do I get a large enough blow to reduce the tree's HT?

(Or alternately, a house with HP of, oh, 200 - how much does a house weigh, anyway - is on fire, and taking 1d-1 burn damage each second. How does the fire get a large enough blow to reduce the house's HT?).

Luke

[Refplace]

I think LWCamps idea about squaring is good in principle but too complicated to play out as a good solution.
I like the IT:DR or dividing damage option better, especially as we have mechanics for that. What would that look like or is it possible to come up with similar results? ie. How much of a divisor is needed to achieve reasonable results for say the naval ships were talking about?

Another thing that came to mind is using Supernatural Durability as a model.
Achilles heal canon fire or fire and you have ships that cant be sunk by muskets and are still hard to hurt with cannon fire, especially combined with higher DR and damage reduction.

I doubt I am a majority but to me the rules need to be set up so that they can be lumped into advantages or rule exemption perks (possibly with high UB cost).
If this is not done then it is impossible to build certain types of chrecters to match and that makes me a sad panda.

[DouglasCole]

Originally Posted by lwcamp

I am curious how you implement this. Suppose I have ST 12 and a greataxe (1d+5 cut). I am trying to fell a tree with HP 100. My maximum damage is 16 (or a bit higher if I have the Forced Entry skill). How do I get a large enough blow to reduce the tree's HT?

(Or alternately, a house with HP of, oh, 200 - how much does a house weigh, anyway - is on fire, and taking 1d-1 burn damage each second. How does the fire get a large enough blow to reduce the house's HT?).

Luke

I think the theory is sound, but you'd need to take a careful look at the interaction between HT rolls, penalties and bonuses for damage per blow, and some sort of thought on repetitive actions.

I'm going to noodle on this more. One day it'll turn up somewhere, I think. :-)

[gilbertocarlos]

Originally Posted by Anthony

To quote myself, "apply it to all damage types".

I did that already, with all Low Tech weapons.

[Daigoro]

Originally Posted by Langy

Why would you be using individual one-second turns? The rules for vehicle combat don't use them, either in Spaceships or the ones in Action.

Originally Posted by sir_pudding

I've said this before, but ships of the line had hundreds of crewmen. Isn't naval combat between ships of the line simply outside the playable scale of GURPS combat?

Originally Posted by apoc527

Any GM who tries to roll out a 76 gun ship of the line's attacks should be keelhauled.

There is a reason, beyond pedantry, to figure out these sorts of stats properly, and it's to be generic.

Yes, we can look in history texts and we've all seen Pirates of the Caribbean or Master and Commander, so if needed we can handwave how many cannon shots a ship can survive or how long it takes to sink one.

The problem is that most of the games I'm involved in are horribly cross-genre, so there's no frame of reference for guessing the effects. What if a galleon is 500 yards from an underwater nuclear blast? Can a mini-gun destroy a ship of the line? Would a TL5 broadside have any effect against a TL8 USS Nimitz? How many of Green Lantern's energy blasts does it take to stop a ghost sloop floating down Wall St before it puts a hole in a bank vault? Using extra-effort?

We must rely on game mechanics to give a ballpark figure. No, I wouldn't game out each second of an extended attack, but I'd use damage averages to guesstimate the results I'm looking for. And if it's things like supers vs tall ships, then turn-by-turn combat might in fact be necessary.

[apoc527]

Originally Posted by Daigoro

There is a reason, beyond pedantry, to figure out these sorts of stats properly, and it's to be generic.

Yes, we can look in history texts and we've all seen Pirates of the Caribbean or Master and Commander, so if needed we can handwave how many cannon shots a ship can survive or how long it takes to sink one.

The problem is that most of the games I'm involved in are horribly cross-genre, so there's no frame of reference for guessing the effects. What if a galleon is 500 yards from an underwater nuclear blast? Can a mini-gun destroy a ship of the line? Would a TL5 broadside have any effect against a TL8 USS Nimitz? How many of Green Lantern's energy blasts does it take to stop a ghost sloop floating down Wall St before it puts a hole in a bank vault? Using extra-effort?

We must rely on game mechanics to give a ballpark figure. No, I wouldn't game out each second of an extended attack, but I'd use damage averages to guesstimate the results I'm looking for. And if it's things like supers vs tall ships, then turn-by-turn combat might in fact be necessary.

QFT. This is the best argument I've seen in favor of reasonably accurate game mechanics in GURPS. You don't even have to get particularly crazy--a Yttarian TL5 ship from Araterre could very well run into a TL8 Infinity vehicle...and it would be useful to know what happens beyond mere GM fiat. OBVIOUSLY, the TL5 ship is going to suffer badly at the hands of TL8 anti-vehicle missile, but it's fun to figure out just HOW BADLY.