As you all can see this man has done some in-depth research and testing. Looking at the results it's quite obvious that the 2-handed weapon class is in serious need of a buff. Not being able to one hit practicly everything is a serious issue that needs to be adressed. Afterall, that is what the 2-handed weapons are all about - being a mighty warrior whom's only flaw is is that he can not kill anything in half an attack.
This baffles me, wy isn't it obvious that every 2-handed weapon should be able to one hit every other player, and succeed at it 98% of the time. The opponents build and gear should not matter in this case, the 2-handed is supreme, and ought to be supreme.
As a solution I think the standard base damage roll of attacks made by 2-handed weapons should add in a +100% damage bonus to every glancing hit it makes, a +150% damage bonus to connecting hits and an AoE bonus of 500% bonus damage to every overhead that makes contact with the opponent, also damaging all nearby opponents for the same amount.
Furthermore the stab should have an addition 200% damage bonus and it should also ignore all the armor the opponent is wearing. The 2-handed weapons should also feature a special attack, that makes the 2-handed weapon wielder spin around like a whirlwind, hitting all nearby opponents for 300% weapon damage.
I suggest the X button for this(same key as Couching on horseback). Another feature of this ability should be that whilst the player is in this special move he is invulnerable to any incoming attacks, both melee and ranged.
I think these changes are wise and would bring back the 2-handed weapons to their rightfull place on the c-rpg-foodchain, on top - that is.
Just, my two cents.
