Fact: Until the Industrial Revolution and its rifled firearms (as opposed to smoothbore muskets), the main weapon of every virtually single army in the history of the world was some form of polearm.
Polearms include halberds, spears, glaives... any sort of blade or piercing tip on a stick. From Sparta until Napolean, virtually every army fought with a blade on a stick. Spartans and Macedonians used spears, Romans used pila, medieval army used mostly spears or polearms, rennaissance armies used pike and shot, and Age of Discovery armies used bayonets on the tips of muskets (such as in Assassin's Creed 3).
Reason being? Polearms have inherently superior reach compared to melee weapons.
Swords, axes, maces, etc. are more sidearms than main weapons. The exception was in the shield wall formation of many medieval armies... designed for defense, not offense, to protect against arrow fire.
That said, I'll move on to my next topic. Armor. Armor is amazing. If anything, the effectiveness of medieval armor is UNDERPLAYED in virtually every RP I've ever seen. Sure, it has gaps. But the areas a good suit of armor does protect? Virtually impenetrable against most weapons. I'll analyze certain weapon types against armor.
One-handed Swords: Ineffective against plate armor. Not very effective against chain armor, except with a thrust. Swords are generally meant as a sidearm for when your main weapon (halberd or other polearm for infantry, great lance for knights) is lost. They're more akin to a modern pistol than they are a modern rifle. And having served as a soldier, I can say I'd definitely prefer a rifle over a pistol in all situations except extreme close range.
Two handed swords: Not quite as unwieldy as many people thing, because your strength is effectively doubled by adding another hand, plus increased leverage by holding two ends of a hilt. Not as good for defense, as it leaves you unable to carry a shield, but better at penetrating armor. Still, it's a close-range weapon, and a more of a sidearm in late medieval and renaissance era combat (where a shield was more or less unnecessary because armor had become THAT good).
Axes / mages: Serve a similar role to each other. They're meant to bash or cleave through armor. Double-headed axes do have a backwing capacity, and aren't noticeably heavier than one-handed axes, but more likely to be two handed axes, while a single-edged axe is more likely to be one-handed. Maces just bash through armor and provide blunt force trauma, as most armor of its era was flexible leather or chain armor, with very few rigid armors capable of sustaining a heavy impact. Both of these weapons are evolved from farming tools, likely due to the fact that so many medieval armies were basically recruited from the peasantry and used their own farm tools in battle.
Halberd: I like this particular polearm especially. It is amazing. An infantry weapon designed to counter cavalry as well as virtually any other infantry force you can think of. It has a hook for unhorsing cavalry, a spike for thrusting, and a blade for basically cutting through anything. Against a halberdier, a swordsman has little chance. Their best hope is to try and block the halberd with a shield and close the distance.. but even then, a good halberdier just steps back to widen the gap again. In fact, a shield is pretty much the ONLY way to reliably block a halberd in order to close to melee.. a typical parry cannot compete with the superior leverage of the polearm. Torque FTW. Halberds remained one of the greatest polearms in history until versatile bayonet muskets became the main weapon of most armies.
Bows: Useful at long range. Volleyed fire is very effective against light infantry. Against heavy armor, they're not very effective. Many people have said that a bow can penetrate heavy armor... but this requires a high-powered Welsh longbow (shortbow and composite bow are right out), at close range, and a hardened-steel bodkin arrowhead... of which none have ever been found. Ever. Virtually every arrowhead was made of a softer iron, because hardened steel was entirely to expensive to be fired off in a single shot. And even assuming close range and hardened steel arrowhead... it can penetrate plate armor. Congratulations. But your arrow only sinks a couple millimeters into your opponents flesh. Stings a bit, doesn't it? Now you've made that knight angry. He's going to kill you.
Crossbows: Potentially more draw strength than a bow, but at a greatly increased load time. However, such weapons as a ballista and a siege arbalest DO have enough force behind them to kill a single heavily-armored knight with a direct hit. But the only chance you ever have of getting off another shot, is if someone stops the rest of them from charging you. Which is what formation tactics are for.
Muskets: Cheap. Easy to use. Cheap. Powerful. Cheap. Inaccurate. Did I say cheap? Muskets allow your massed armies of peasants to switch from pitchforks to firearms. Ludicrously inaccurate, they still have the ability to pierce MOST (not all) armor. At short range. Because most of your shots will miss, every time. This is why Renaissance formations used pike and shot... pikemen kept the enemy at a distance, while muskets shot them. This was one of the most effective formations until bayonet muskets allowed a single soldier to serve as a spearman AND a musketman at the same time.
Despite what most people believe, renaissance heavy plate armor such as Maximilian and Gothic armors were built to stop bullets. Their thickness was doubled with the invention of gunpowder. Heavy armor makes you immune to virtually anything UNLESS they hit your vulnerable points... of which there are bound to be a few, but let's face it... an armored warrior should defeat an unarmored warrior of equal skill every single time. Hands down. That's... why armor lasted so long. And also why armor came back... I wore armor in Iraq. It could stop bullets. I felt a lot safer that way. I also carried a load heavier than most medieval knights carried, and was still able to move fairly effectively.
The reason armor went out of fashion was because of two reasons.... expense, and the development of professional armies. Aristocrats who could afford to buy armor capable of stopping bullets (knights) were no longer required to serve on the battlefield... the State simply used its treasury to equip a professional army (a concept which hadn't existed since Rome and the Byzantine Empire). If you can buy a hundred muskets for the price of one suit of Maximilian armor, why waste money on armor? Flesh is cheaper, as far as they're concerned. Particularly flesh equipped with powerful, easy-to-use weapons at a cheap cost. So that's what armies did, from the advent of professional armies up until today.