wepons

[The Skarzs]

Not necessarily. Half-swording really doesn't take much room, and in close quarters neither opponent would be able to swing to slice much anyway, so stabbing would be the name of the game. This is also where having a short side weapon would be necessary, because saving your life is not to be taken lightly.
Weight isn't much of an issue, since most longswords weighed in at about four pounds, and I've seen historical- if exotic- knives heavier than that, and the point of balance gives it its quickness in strikes. Of course, it has that downside that every weapon does: its user.

As for "how powerful" the weapon is, long swords will obviously cut better than shorter swords, but most short ones were meant for stabbing rather than slicing. In the end, you can't say that one weapon is more powerful than the other because all weapons will kill, but in different ways.

[Lady Ashenwyte]

Just to note, medieval weapons and armour were lighter than what is thought today. Chain mail weighs as much as a small child, which was shown in a demonstration at the Metropolitan Museum. Also, plate armour was lighter than mail and is about 60 pounds.

[Wylder Treejumper]

Yes, your sword won't weigh 20 pounds... nor will it be an inch and a half thick, as it might seem from some fantasy artists.

[Izeroth]

 Spears are great when used en-masse, but an individual spearbeast doesn't stand a chance against a swordsbeast.

[The Skarzs]

[Lady Ashenwyte]

Spears are great when used en-masse, but an individual spearbeast doesn't stand a chance against a swordsbeast.

On the contrary. A relatively skilled spearman can defeat a swordsman individually with ease. Range and skill are the skill are the things that matter in a duel, and so are tactics.

[Izeroth]

 A skilled swordsman would be able to easily maneuver around the spearman, avoiding his weapon while at the same time striking.

[Lady Ashenwyte]

A skilled swordsman would be able to easily maneuver around the spearman, avoiding his weapon while at the same time striking.

What would he strike? Not the shaft, the wood's too hard. And he can't strike the spearman from his current range, he would strike air.

[Izeroth]

 If the spearman has a two-handed spear, the swordsman could simply stab him in his undefended back. If a spear and shield, it would be harder, but still possible.

[Lady Ashenwyte]

But the swordsman has to circle and close in on his opponent, who has the range. It will be very difficult to acheive that without a shield.

[The Skarzs]

If you're being attacked, you would hardly let someone get around to your back.

[Izeroth]

If you're being attacked, you would hardly let someone get around to your back.

It would be hard to maneuver while holding a heavy, long pole. If the spearman was wearing armor, that would make it even easier to attack them.

[The Skarzs]

Yes, but it would be a simple matter to turn around, whereas the swordsman would have to move several feet.

[Luftwaffles]

How accurate would it be if I could just throw my dagger at someone who's using a larger weapon? Could I kill the guy or that's just on the movies?

[The Skarzs]

If you're a good knife thrower, certainly!
In fact, there's a silly historical technique of unscrewing your sword pommel and throwing it at your opponent.