Perhaps the single-most useful tactic in group PvP, the charge is little understood even by those who can most benefit from it.
Let's break it down.
Imagine that you are in, say, the Battle for Praag scenario. You and your pals are loitering contendly around a flag, perhaps picking dandelions, when all the sudden a great mass of red names comes flailing toward you, dashing past your befuddled meleers into your creamy casters.
That is a charge.
So you ran screaming in a panic away from the charging enemy, likely to be cut to pieces in retreat. You regroup, respawn etc. by your guards, while the enemy (lets call them "order") loiters around the flag closest to your spawn point in a seething mass. They taunt you; they insult your mothers (or in the case of greenskins ... parent?). So what do you do?
All to often this is what you do: you cherry-pick. There is a back and forth of dashing attacks and retreats. Some from both side die, but no ground is gained or lost.
The problem with this is two-fold:
1. you are at a point-deficit. You need their spot, but they don't need yours.
2. it's a shitty strategy.
What you should do is ... charge.
The problem with a charge into a set enemy is this: it takes guts. Every individual knows that if they charge in alone, they will get crushed humiliatingly. If you all go in together (assuming here you are competitive in numbers and overall power, not always the case) you have a good chance of pushing them back and doing to them what they did to you. Namely, routing them.
It's one of those trust dilemmas, do you take a personal risk (getting wtfpwned) relying on your teammates to rally to your side or do you wait around taking less risk, but gaining less reward (hey we killed one witch hunter woo!)
Not surprisingly, I die a lot in these situations, because I'm unwilling to do the lazy, wrong thing. I don't want to pussy-foot around and farm 1 kill to our 5 deaths, while they rack of scenario points. So I charge in (I'm a tank after all) and more often then not, no one else does the same, and I'm unceremoniously beaten like a pinata (on fire).
What happens in a charge is this: you change the plane of the attack and your force the enemy to make choices.
If there is one enemy in range, they all attack that enemy naturally, and healers can't keep them up.
If there's 10 enemies in range, then each individual has to pick the best target. Damage is split, healers have a better chance of keeping up with that damage and meanwhile the attackers are causing more damage to the enemy, requiring more effort from the healers and possibly requiring them to reposition or change targets midstream.
Add to that the benefit of shared buffing/debuffing and shared cc benefits and you can see why the charge gives you the best chance for success.
There are other factors of course: who do you attack in your charges for one. Don't hit tanks obviously, but also you want to move in a group, but not too clumped up, so that you can't be isolated on the one hand, and can't be casually group cc'd and aoe'd.
Stay grouped, focus your damage, help your teammates and win.
Charging: it works. Give it a try.
PS. Strangely no one has a problem with implementing the charge in oRvR. O-RvR is also where you'll most likely see the best counter strategies to the charge: the tank wall and the isolation move (in which you drag a part of the charge away from the main group and focus them down).