I'm making a Barbarian Goliath for a game coming up for D&D 5e. These questions have probably come up a lot, but without any real consensus. Basically, my goal is to have my Goliath wield a Large Greatsword while not being overpowered. The DM is open to some house rules as long as they are logical and don't break the game.
Weapon size scales damage up by doubling, tripling, or quadrupling damage dice. In this case, 2d6 becomes 4d6. Would there be a difference between 2d6 hitting normally to 4d6 hitting half as often with rare criticals?
I came up with these to try to incorporate the mechanics with weapon class and a feat along with it.
New Weapon Property - Extra Heavy; Weapons with this property are one size larger than the user (small creatures cannot wield Extra Heavy weapons). Weapon damage dice are scaled to the weapon size, but all attacks made with this weapon are at disadvantage.
New Weapon Class: Great Weapons; All Great Weapons have the Extra Heavy and Two Handed properties. No class or race is proficient with Great Weapons.
New Feat: Massive Grip; Increase your Strength Score by 1, to a maximum of 20. You can benefit from the versatile damage bonus from a weapon with only one hand. You become proficient with Great Weapons.
I added the versatile thing just out of logic, but I don't know if that's pushing it for a feat. I wouldn't think so considering the OP benefits of some feats like Lucky.
**Another benefit would be that improvised weapon damage is based on an existing similar weapon. Ex: Swinging a tree would be like a Great Greatclub for 2d8. It would require two feats to become proficient with it, and it would be at disadvantage.