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Strength, creature size, hp, damage...

Great Umbrage

First Post
I want to address the issue of Strength, and its correlate statistics, in the 3E D&D game.

By necessity, I will touch on the idea that the gargantuan creatures of myth, as realized in the D&D game, cannot exist in the proportions that they do, but nevertheless accept the premise that they do indeed exist and that we must therefore give a treatment of their attributes. What I am referring to is the fact that giants, for instance, cannot have the same relative proportions as humans and be able to support their body weight, due to the observation that with an increase in height, mass increases by that height factor cubed, while cross-sectional area of a supporting appendage, such as a leg, only increases by that height factor squared, if it keeps the same proportions as a human.

Example: A 12-foot tall giant is twice as tall as an average 6-foot tall human, but weighs EIGHT times as much (volume being a cubic function of height). However, his legs would only be FOUR times as thick (area being a square function of height) and therefore be subject to twice the pressure (say, in pounds per square inch) as a human. Assuming that the giant is made of flesh and bone as is a human, then it would not be able to support itself. This is even more pronounced if the height factor is greater...a 60-foot tall giant would be putting 10 times the pressure on its frame, etc.

However, I am not trying to denounce the existence of giants--they don't exist; this is a fantasy game. I am trying to look at the relationship between Strength, hit points, and damage in D&D. I will work under the premise that giants can somehow support their weight.

The Monster Manual and other books have detailed the relationships between different size categories and listed recommended Strength, hit dice, etc., as well as a height and weight range. In short, each size category includes creatures twice as tall or long as the creatures in the size category before it. That is, a Small creature is half the height/length of a Medium-sized creature, which is half the height/length of a Large creature. As well, the corresponding weight ranges go up in factors of 8, as it works under the assumption that creatures in a type are made of the same kinds of matter and in relatively similar proportions of each kind of matter.

Looking at the recommended Strength values, they increase by either +8/category or +4/category. Aberrations, Animals, Beasts, Dragons, Magical Beasts, Monstrous Humanoids, and Vermin get +8/category above Medium (mostly Quadrupeds, or creatures with a greater horizontal than vertical face), while Constructs, Elementals, Fey, Giants, Humanoids, Oozes, Outsiders, Plants, Shapechangers, and Undead get +4/category above Medium (essentially Biped creatures, or creatures with a greater vertical than horizontal face). This is equivalent to approximately a x2 carrying capacity for Bipeds and about a x4 capacity for Quadrupeds per category. Factor in a x2 for carrying capacity per size category (page 142 in PHB), and thus Bipeds carry x4 more weight, and Quadrupeds, x8.

However, we note that bipeds do not increase carrying capacity as quickly as they do mass (x4 vs. x8). In addition, the method by which the designers arrived at these values is somewhat erroneous. They should be x4 for both bipeds and quadrupeds, because cross-sectional area of bone/muscle is squared, not cubed; thus for a x2 increase in height, the carrying capacity should only increase by x4 for both bipeds and quadrupeds.

One might argue that quadrupeds divide their load between four limbs instead of two, but that applies for quadrupeds of all sizes, and therefore, the multiplier between sizes should still be 4, not 8. A quadruped of the same size as a biped should have twice the carrying capacity that the biped does (though not twice the Strength).

In short, the Strength increase between categories should be +4 (actually, +5), and not +8 for quadrupeds.

However, we are operating under the premise that creatures can somehow carry the same relative weight (especially body mass) regardless of size in this fantasy setting; that is, a 12-foot giant should be able to carry the same size object relative to his body that a 6-foot tall human can.

In nature, real life nature, that is, the thickness of a creature's limbs increase by more than a factor of 2 when the height is increased by 2...it is increased by about 2.8 (square root of 8) so that the cross-sectional area is increased by a factor of 8 and the creature is able to support its body mass.

In fantasy, we can assume that the physical or magical laws operate differently. The easiest assumption is that larger creatures are made of sterner stuff than smaller ones...that is, stronger bones, muscle tissue, whatever, by about 1.4 times (square root of 2). In which case, they should have a Strength increase commeasurate to their mass increase, or x8 (+10 STR/category), so that they can lift the same things as their size that smaller creatures can at theirs.

Now, with regards to the Hit Dice suggestions, they increase by a factor of 2 per size category for most creatures...a Medium-sized humanoid has 1d8 hp, a Large humanoid has 2d8, a Huge humanoid has 4d8, etc., except between Huge and Gargantuan sizes, wherein they quadruple. The exceptions are Dragon and Elemental subtypes, which have different ratios, but we'll deal with the increments used for most creatures, as described above. The Hit Dice recommendations should be considered alongside Constitution recommendations. These increase by 4 per size category, or a +2 hp bonus/category starting from Medium-size, which has a 10-11 recommendation, or 0 modifier.

The Hit Dice ranges therefore look something like M: 1d8, L: 2d8+4, H: 4d8+16, G: 16d8+96, C: 32d8+256, or average hp of M: 4.5, L: 13, H: 34, G: 168, C: 400. The difference is about 2.5 times per category, except for the irregularity between Huge and Gargantuan, where it is about 5 times. In general, HD increase as a direct function of height. But with the CON modifiers factored in, they increase a bit faster than height...This is nevertheless quite different from the increase in mass.

However, there is nothing to indicate that hit points are anything but linear. Yet, a creature twice as tall and 8x as massive as a another creature should be able to take 8x the damage. They should therefore have 8x the number of hp.

Another indication of the disparity is the damage recommendations for various attacks. Let us assume that the damage inflicted is a function of momentum, or mass times velocity. The Slam attack, for instance, should inflict 16x the damage per size category...it is a function of mass (8x) times the velocity achieved (2x, a function of height). Even accounting for the Strength bonus to damage (+2 or +4/category), it is insufficient.

Thus, hp cannot be a linear function of mass, but a function of height. Damage is therefore scaled as hp, which is not linear, or straight line function comparing damage and mass, but exponential. That doubling of hp between Medium and Large creatures is representative of 8x the mass. 1hp means a lot more to a Large creature than it does to a Medium or Small creature. However, weapon damage remains the same, regardless of what you are striking...

These are some of the problems integrating the D&D system into a setting where you wish to set benchmarks for what every statistic represents. This is especially of interest when designing a Supers game that requires consideration of ability scores, especially Strength, that reaches high numbers. What is the relationship between hp and Strength, damage and size, etc.?
 

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You are attempting to apply real-world physics to creatures in a fantasy game. Please realize that this is not likely to make sense.

Note that you certainly shouldn't expect hit points to scale relative to size or mass, because they are not a purely physical entity. They represent a combination of damage, fatigue, luck, and "dude factor." A high-level human fighter has far less flesh on his bones than any giant, but he can probably take more of a beating-- even if they're both unarmored and defenseless.
 

The system itself applied real world physics to the fantasy game when it started to delineate the Strengths, masses, etc. of creatures. I merely wish to make the system more consistent and sensible.
 

I might suggest that while the designers did include height, weight, size and strength as parameters, their primary mission is not replication of the real world but game balance.

Large, huge and gargantuan creatures are generally fearsome enough without benefitting further from their great size. As with each ed. of the game, size/mass is slighted (consider the 1/4 ton 1st ed. horse with 2 HD) for ease of play and game balance reasons (IMHO). For most, this is an acceptable departure from physics-based realism.

I have played a variant with HP largely based upon weight. It was interesting, but required extensive rework of many rules. For example, enlarge became simply broken...
 

My major concern was that as creatures got bigger, their Strength scores were insufficient to carry their weight around. I simply suggested that Quadrupeds should generally have x2 carrying capacity compared to similarly-sized Bipeds, and that each category increase should be accompanied by a +10 in STR. The x2 extra carrying capacity/size category was the "fantasy fix" to the physics dilemma, but the +10 STR really is necessary, as opposed to only a +4 STR for some creatures. Besides, it makes sense.

I only bring up the HP and damage because in Supers games, there are many instances of characters with Super Strength, and thus, someone similar to Superman, with a STR near 100, would have a massive damage modifier if the D&D progression is used. I know Mutants & Masterminds use a different progression for damage that gives generally smaller modifiers and less damage. However, before settling on a good system, the implications of Strength, size, hp, and damage should really be considered.
 

Great Umbrage, that was a great post. Have you seen the Grim n' Gritty hit point rules? Discusses a lot of the same things.

Just wondering, though, mayhap if your train of thought is heading in this 'logical' direction then perhaps you might want to consider a different game system where this sort of thing is addressed more to your liking.
 

I just assume that most of their increased strength is magically channeled into preventing their body from crushing itself and allowing them to move normally, leaving relatively little effective strength for more mundane functions.

This type of magic works on a very primal level and is not subject to things that normally disrupt magic, such as dispel magic, antimagic fields, and dead magic zones. This is also the reason why creatures like Golems and Undead can still function in magic-dead areas.

Basically, real world physics does apply, but is being magically counteracted or compensated for in certain instances.
 
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While the reasoning behind game mechanics can and should be involved and logical, the mechanics themselves should remain relatively simple and straightforward. I've been severely disappointed by the limitations facing d20 system that I've come across in the past year of gaming and writing, but I still want to try to redeem what I feel is one of the simpler systems.

In response to Caliban, I know that most of fantasy simply accepts that something like what you prescribe happens, but remember too that giants not only have to carry around their own weight, but also the weight of giant-sized objects. Your reasoning accounts for the giant's mobility...if he is naked, but does not address the fact that most giants, especially civilized ones (cloud, storm) will likely be wearing and carrying things. How can a giant warrior attired in full battle armor and sword move with even part of the mobility of a human in full armor, which in itself is not that gracefully.
What I've also noticed is that the giants in the Monster Manual II are quite strong, especially the giant-kin, who are not supposed to be as big as the true giants. The Firbolg has a Str of 36 and the Fomorian, 34, which is about 10 more than the guidelines...the values actually sound pretty good. I think a new set of guidelines would help, but its impact on game balance would likely be an issue. The problem lies, really, in the abstraction that is hit points, and the escalating ability bonuses. I somehow am beginning to find the damage system in Mutants & Masterminds more and more appealing.
 

I would like to add my voice to those calling for you to find a new game system, Umbrage. Clearly, this game is not for you.

The problem is, that there isn't one that addresses this problem "realistically".

Applying this kind of logic will knock the dragons out of the sky, pluck the mermen from the sea, and silence the wizards forever. I don't think I would want to play in your gameworld, Umbrage.
 

Explain, exactly, how my suggestions would knock dragons out of the sky, etc.? I already stated that my premise is that giants can move around normally and dragons can fly, etc., but that the system itself does not allow for it with the way it sets up their statistics. What I suggested was for the Strength scores to be redefined--simply by making recommendations for a +10 Str/size category and for quadrupeds to receive a x2 to carrying capacity compared to bipeds.

What 3E has a problem with is its consistency. The Str of giants relative to humans, as it stands, is way too small for their size.

I reiterate: my suggestions would allow giants to actually be able to walk and carry a decent amount of equipment--quite the opposite from what you suggest. If you had bothered to read my posts, or even my dumbed-down summary, you would understand that.
 

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