Oh dear. I'm sorry to jump in, but this post has so many errors and misconceptions I'm going to have to join Simon and Tom to comment.
Besides the point Simon made about RQ and BRP having to cover a greater range of real world periods, you really shouldn't ever try to make claims about Stormbringer armour. Its a game based on pure fantasy, created by a drug-addled, idea purloining author, and is subject to no more reality than its own need for a dramatic story!
Originally Posted by QueenJadisOfCharn
Er, not quite. Bronze can be hard, soft or a mixture of both depending on its alloy and how it is worked. Just because it is bronze it doesn't mean its immediately brittle, nor that it is more likely to shatter than iron. That can depend on the iron's purity, casting/forging temperature, whether it was tempered and a few other things. You are making sweeping statements.
Bronze is far more frangible than iron or steel. Though most bronze is harder than most iron, and the absolute limits of bronze hardness are twice or more that of iron, bronze is more likely to shatter and crumple under stress.
Utter rubbish, starting with the reasons Simon first mentioned.
Bronze armor works primarily by deflecting points. Unlike steel plate or mail, which is almost physically impossible to cut through, it is quite possible for a for man to drive a spear right through a bronze breastplate and the man inside. In fact, bronze's properties make it better as a sharp weapon than as armor, meaning a bronze age warrior faces a double inequality: absolutely inferior armor and relatively superior arms. In some cases bronze weapons perform better than iron weapons, add they're stiffer and can be sharpened more.
All armour is made to be 'just good enough' to face the weapons of its era. Pre-firearm body armour was never constructed to be bomb-proof and indestructible. Rather it is fashioned to be as thin and light as humanly possible whilst still saving your life; in effect it is ablative to the point that it is only supposed to last a single battle or lethal encounter. There is time enough to repair or patch damage after the fighting is over. The same thing holds with shields.
Yes we have literary references to bronze panoply being thrust through by spears. However we also have archaeological remains which show steel armours being buggered too. What you seem to forget (or even know) is firstly that almost all historical mail is only ever made of iron (the softness allowing links to deform around a thrust, absorbing force and not shattering), and secondly the quality of steel used in plate armour and its hardness varies tremendously over the period of the 14-16th C. Most early steel is unhardened, full of slag and has a poor crystalline structure which makes it prone to weak spots or even tearing.
The first historical artefact we have of a possibly case hardened helmet is the Pembridge Helm from about the mid Fourteenth Century, and it wasn't until the late Fifteenth Century we start to see consistent martensite structure and only then from harnesses made by select families of master armourers. Most of the stuff available was munitions-grade either over-hardened to become brittle or not hardened at all.
So all plate armour, whether bronze, iron or steel utilised deflective surfaces for its primary defence. Yet even the top quality steel armours could still be punctured by polaxes, cracked or folded by great swords or simply bypassed by the concussive force of hammers and mauls.
"Then Jacques de Lalaing, seeing how aggressive his adversary was, whirled the point of his polaxe around, and struck 3 blows on the eye-slits of Diego, one after another, in such a way that he was wounded in 3 places in the face...the first blow landed on his left brow, the second on the point of his forehead, and the third above the right eye." - Tournament in Valladolid 1447
Bear in mind that these tournaments were not intended to be to the death and thus they used specially rebated weapons as to not kill or maim their opponent. Tourney polaxes did not have especially sharp points, nor were they permitted to be long (the points that is).
You are making another sweeping statement based upon shaky premises. The mass of bronze for example can vary between 7400 and 8900 kg/m3 depending on the alloy, whereas homogenised steel can be from 7400 to 8000 kg/m3. So in terms of weight they are very similar.
In order to be viably strong bronze armor is also quite a bit heavier than steel or iron, a bronze greave well weigh as much as three times that of a steel counterpart one reason we don't have Attic full plate. This is an important feature, because between the weight, lower relative benefit, increased absolute scarcity of bronze and absolute poverty of the pre-classical world you well see VERY FEW people in full 'hoplite' armor, and essentially no one in more. This means lots of bare flesh in every battle; flesh which is no match for even bronze edges.
As to hardness bronze can achieve a hardness of around 200-230 VPH when cold-worked (hammered). Mild steel (of which most of the early plate armour was manufactured from) can only achieve about 100 VPH. Whereas hot-worked, air cooled carbon steel (late 14-16th C munitions armour) averages 250 VPH. It is only the exclusive and very top quality martensite steel of the late 15th C (based on samples from Augsburg from 1480-1551) which reached between 240 and 441 VPH. So where you get the idea that a bronze greave should weigh three times its (undefined period) steel counterpart I have no idea.
And just to broaden the areas where you might perform some further research, are you aware that in spite of its rarity and expense, the Romans continued to produce and use bronze helmets for legionaries, cavalrymen and gladiators up until at least the 3rd C AD, well after they industrialised the manufacture of iron and mild steel.
None of which is borne out by the metallurgy or historical examples.
My suggestion is that weight be tripled for armor, DR reduced by 1/3 and HP reduced by half. For weapons, double weight for small blades and bludgeoning weapons, and triple the weight for Longsword and full sized axes. For all weapons reduce damage slightly (perhaps -1) but reduce HP by half.
You have obviously never tried to hack through wicker-work with a swung blade, nor penetrate it with a spear. They may be light, but provided it has not dried out from careless maintenance, wicker is a bitch to hew or thrust through. Even trying to cut through hide leather with a sword is near futile. Remember what I said about shields above, that they are expendable defensive devices which only have to last a single battle. Peoples who used these materials didn't do it because the only alternative was soggy toilet rolls, but because they actually worked!
As I'm primarily talking the near prehistoric and very early historic periods, shields will be even crappier; basically wicker or leather of limited use except as a disposable arrow catcher. Even bronze and wood shields as were used much later will be penetrated by a solid blow, so we're taking 1/5th to 1/2 DR and HP, and that's being generous.
Amongst others the Aztecs, Incas and Pacific Islanders used stone weapons for centuries to great effect, and if not for the advent of disease, cannon and firearms would have continued to prove their effectiveness many times over in hand to hand combat. Stone in fact produces some of the most durable (and beautiful) weaponry known to history and they remain extremely effective.
Copper is much like bronze, but inferior in all respects. Stone would also be common in maces, axes, arrowheads, knives and tools in general. Many people outside the small cores of civilization and urbanity will still be living in primitive hunter-gatherer and partial conditions. They will have essentially nothing but the simplest handicrafts, and metal will beer outside their income and possibly outside their experience altogether. Some will be in a more mixed state, especially if they have organized war bands or valuable resources to barter with. Stone weapons would be terrible, incredibly fragile, very heavy, virtually impossible to repair and very tedious to produce.
Since the hey-day of truly superior steel is less than a century in duration, compared to several thousand years of bronze superiority followed by half a dozen centuries of metallurgical parity I think you are being somewhat unfair. Most versions of BRP games cater to the Classical and Medieval ages, not the early Renaissance when hardened steel was actually produced for armour.
This was probably the biggest deficiency I found I the BRP family, there seems to be acknowledgement of this fundamental issue; and considering it's original setting was Bronze Age it's even more glaring an omission. I'd course we can't for everything in a book but I've seen only one fan book that even acknowledges that bronze and steel are different, and it's far too conservative/favorable to bronze IMO. GURPS handled this issue in their core rules, and I might use them as a rough guideline to audit/edit BRP and RuneQuest weapons/armor top confirm properly to the relatively junky and bulky ancient equipment.
I disagree. Weapons and top-of-the-line armour were in parity until the Renaissance when armour tech advanced so much it forced a similar spur in the development and adoption of great-weapons.
The further back in time you go, before the renaissance anyway, the more of an edge weapons have on armor (somewhat balanced by greater effectiveness of static fortifications on the large scale), and bronze age warriors face the same sort of situation as modern soldiers; their armor is really only there to stop glancing blows and stray projectiles; against a direct hit it's of very limited utility and against a well aimed hit it's useless because overt half the body is effectively naked/unarmored.
Now you are just being bigoted. See Simon's list of early cultures, and add to that the empires of South America and Africa. Professional warrior classes and craftsmen have been in existence for at least as long as recorded history, if not longer.
Skills will also be far more limited, both in terms of what skills one can acquire, how intensively one can train it and how crude the available tools are. It's not likely people with high skill ratings, other than some communication skills, would really exist. Wealth and accumulated techniques make a huge difference, the more talented the warrior or scholar in the first place the greater the benefit from advances in technique and tools. It's simply not possible to train warriors to Immortal standards, much less chivalric or Ottoman standards, without this vast accumulation of knowledge, wealth, stuff and free time; it doesn't matter if you have a 19 intelligence or a 20 dexterity, you will not have the opportunity to exercise your talents to that limit.
Ignoring the system mechanics fallacy, this frankly doesn't even deserve a response.
Other than survival and communication skills the limits would be much lower, and even these benefit immensely. The smartest Babylonian priest may write a brilliant epic, but it's going to be limited and formulaic compared to Homer, much less Dante (or Robert Howard). These people are basically cavemen and 80 word vocabulary starving farmers with bricks and asphalt, and their greatest aren't as well off as poor people in Mexico in terms of access to accurate information, food and time to develop specialized skills.
Honestly Jadis, I think you should study the fields you are debating before throwing yourself into mechanical revisions. Not that you can't change whatever you want, feel free to tinker! But some of your ideas are poorly informed and if you are going to the effort of making things realistic, it behoves you to do more research first.