It’s a fundamental element in most RPGs: Strength modifies hit chance and damage. From time to time, a few heretics claim that the main attribute for close combat should be speed, dexterity, or something like that, but the answer to these people is always the same:
“You are as ignorant as you are [probably] ugly. For a trained warrior, speed is strength, and strength is speed. The damage any object may cause is basically speed x mass, so the bigger and stronger you are, the faster you will hit, and the more brutal you will be.”
The idea that, somehow, a nimble fighter would beat a 240lb man probably comes from the same crazy hole that gave us Waif-fu and similar nonsense.
[Note: as a commenter -dmdr- noted, there are many games that use Dexterity (or something similar) as the underlying skill for combat. I still think that’s a mistake, and I suspect the error comes from confusing agility/nimbleness with skill (or character level, for those games that use that.) The designers imagined one of those fast fighters one can see in movies (a Yoda-like thing, for example) and assumed that such speed was what the dexterity ability scores reflects. In fact, that speed is not a function of some natural power but of years of training (and in the Yoda example, superpowers or The Force -which, by the way, probably gave him extra Strength to be able to do those things-) So, the answer wouldn’t be that the warrior has a high Dexterity but that he is a high-level character.
Also, there is the error that strength and speed are somewhat incompatible, which is nonsense. Speed is Strength. Weak people are slow and clumsy. And yes, there are big, strong people who are also relatively slow and ineffective when fighting, but that’s because they are not trained in hand-to-hand combat or in any martial arts. If they were, they would crush you (and that’s the reason I created these optional rules.) Imagine a 3-meter ogre trained in kung fu, and then tell me his Strength shouldn’t matter that much because it’s all an issue of being fast and nimble.
I do not deny there are certains moments when something like Reflexes may matter in combat, but that’s why those scores add to AC or Defense. In any event, what I will never accept is the idea that the main skill governing unarmed combat should be Dexterity instead of Strength.]
In fact, here I will argue that games like D&D underestimate the importance of strength, at least in relation to unarmed combat. That’s understandable, though, because unarmed combat is usually and afterthought to the more general combat rule system. Also, the game implicitly states that unarmed combat is the easiest skill to learn (because everybody can punch and kick) and it doesn’t matter much if you are a “martial artist” or not.
What I present here is not a new complex rule system for martial arts but a simple modification to the Strength table and a few optional rules. Everything else still works like always has.
Basically, what I propose is just adding another column for “Bonus to hit,” but this one only for unarmed combat when: (1) NEITHER you or your opponent are using any weapon, (2) AND the attacking character has a proficiency in unarmed combat. So, a big, burly mage would not use that new column because (probably) he doesn’t have that proficiency, and a trained fighter would not be able to use that column because his opponent is attacking him with a dagger, and that nullifies the special bonus of the new proficiency.
“Proficiency in unarmed combat” simply means you have some kind of martial arts training (karate, boxing, judo, whatever) or that you are very good at knocking people thanks to your bar-fighting experience. If you are playing 3rd edition, it works like a feat, similar to a “weapon proficiency” but with a few differences. Also, please note that in this optional system, “Unarmed strike” is not a “simple weapon” anymore but it’s own weapon category (“Unarmed combat”) with its own proficiency and mastery feats.
Proficiency in unarmed combat, like other basic proficiencies, doesn’t give you any bonus to hit, BUT unlike other proficiencies, you don’t suffer any penali¡ties (the standard -4) either. What does it do then? Well, it allows you to use your strength when punching people to its full potential. In other words, your bonus to hit thanks to your Strength will be bigger. All warrior classes (fighter, paladin, ranger, barbarian, and monk) have it and, if you are playing D&D 1st edition, also dwarves. The other classes need to purchase it.
Optional rule: for those who want to create a more hardcore or brutal simulation, you can give a penalty to characters that don’t have the proficiency in unarmed combat, but I think it should be smaller penalty, something like -2 or -3.
Once you have that proficiency, it is assumed that you have some knowledge of a martial art (or its animal/monster equivalent) so you can use this new column to kick some ass IF the other combatant is also unarmed.
[The second table could be expanded so the bonuses won’t jump, for example, from +2 to +4 in a single leap]
As you can see, the new column basically doubles your STR bonus. That makes those extra points in the 18-18/00 (or 16-19 for D&D 3E) range really important for someone in the business of crushing skulls with his hands. The rationale behind this is the same one that created weight classes for boxing: if two boxers fight each other, the bigger one will almost always crush the smaller one. Differences in Strength and size don’t matter THAT much for people wielding weapons, but for trained martial artists they do.
You may think that some of those bonuses to hit are too high, like +12 for 24 STR. Yes, they are quite high, but they have to be. Anything beyond 18/00 or 19 STR is basically inhuman strength. 24 STR is the strength of a Storm Giant, a 6 meter tall, 5400 kg humanoid. Really, if you are stupid enough to try beating a monstrosity like that at a boxing match, you deserve all the +12 of the world against you.
Note that this applies to all sizes and types, so if a very idiotic rat attacks you and you try to kick it, punch it, or -uh- bite it, you (but not the rat) will use the new column for bonus to hit.
ObligatoryOptional rule: What’s that 3E nonsense about “weapon finesse” for unarmed strikes? Burn that heresy!
“Wouldn’t that mean that little animals like rats suck at fighting humans?” Eh… yeah, they ARE little animals, they should suck.
Note that monsters and creatures need that feat to use it, too. Some may have it, others probably won’t. For example, a dragon probably wouldn’t it since there is no reason to assume it had any opportunity or need to train in unarmed draconic combat. As a general rule, martial humanoids (orcs, hobgoblins, and so on) probably will have that feat. Many savage animals, especially predators, may also have their own version of that proficiency, but I’ll leave that to your discretion. I think, however, that many should for the simple reason that trying to punch a tiger or a wild boar is a very, very bad idea.
Now, why does this optional strength system applies only when both combatants are unarmed? Simple, because weapons equalize the combatants and make strength a little less relevant. On the other hand, when fighting unarmed or wrestling a gorilla, it is then that being a big mofo is extremely important.