I don't want to brag, but... okay, I do want to brag. I'm good at War of the Roses. This came as a shock seeing how mediocre I usually am at shooters and deathmatch-type games in general. For those of you who might not be very proficient at simulated medieval maiming, I've compiled some tips to help you lead your chosen house to glory.
Which had better be York. York is the correct answer.
There really isn't any way around this, but it's true. Especially the footman, which is your only option when you first start the game. He comes equipped stock with a sword that can't really do pig droppings to anyone in plate armor unless you can manage to jab them in the eyes, which takes a lot of practice. Until you unlock the Foot Knight (and subsequently, the ability to make a custom class), go for weaker targets like bowmen. Trying your hand against those clanking behemoths on the front lines is only going to frustrate you.
While you're moving in to slice up some ranged foes with your weaksauce starter sword, you may notice that they have a tendency to fill you with arrows. This is a good time to learn how to make them curse your very name, which will come in handy even when you do unlock better equipment down the line. First, never run out across a big, open field - especially one with buildings overlooking it. Always try to make sure you're not in the same open "lane" for more than a couple seconds, using buildings, walls, and tress to cover your advance. Remember that you can press Ctrl to crouch behind low objects.
When you do have to cross open ground, or you're closing in for the kill, run in an unpredictable zig-zag pattern to throw off the enemy's aim. Once you get in close enough, the fight is practically over. The sword most archers and crossbowmen carry is somehow even worse than the one you have.
Once you unlock a custom class (which are really the core of the game), you should buy up your perks before anything else. I recommend Shield Breaker and Break Block, as it can be pretty hard to kill shield-bearers without them.
My weapon of choice, once unlocked, is the two-handed Galloglaigh Axe. It has enough power, especially once you upgrade it with the right fighting style and components, to make most armor a joke. Which is good, as heavy plate is pretty dominant on most servers right now. The only problem is that power requires you to be extra precise, as only hitting with the head of the axe does damage. If you're pressed right up against someone, you'll just whack them with the haft.
In Single Player training, you can usually find some bots that are standing still. Try out some different swing heights and standing distances to find the "sweet spot" for maximum killosity.
A lot of people are wearing plate right now, and that's fine. It'll protect you from most one-handed weapons, but a skilled player with the right two-hander, or basically any moderately skilled archer, can punch right through it. So I say, leave it at home. Wear the least encumbering gear you've unlocked, and zip around killing people with little to no regard for your own safety. Yes, this will make you more vulnerable to otherwise laughable things like the archer default sword, but if they can kill you with that glorified butter knife faster that you can cut them completely in half with your giant axe, you're doing something wrong that has nothing to do with the armor you're wearing.
If you don't believe me, ask someone from the beta press events about the annoying guy in the peasant robes. They'll know which one you mean.
It is highly dishonorable to walk right over a comrade in arms who is bleeding out when it only takes you about four seconds to get them back into the fight. They might save your life a few seconds from now. Also, if you have any damage on you whatsoever and there are no enemies nearby, duck somewhere out of archer-sight and patch yourself up. Even if you've only taken a small amount of damage, that could be the difference.
One who goes into battle hoping to live will surely die, while one who goes into battle expecting to die will emerge victorious. Pretty sure Sun Tzu said that. Or it could have been Zero from Borderlands. I'm not entirely sure. A lot of the frantic melee combat in War of the Roses is about psyching your opponents out. You want them to be afraid of you, and be under the impression that you don't give a baron's chamberpot about them. Move around a lot, take swings even when your timing isn't perfect, and don't seem overly defensive. When you can, flank from unexpected angles.
Now get out there and kill something!