Is a feat allowing Large weapon use balanced? [closed]

Question

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.

Answer 1

This feat seems unnecessary.

Massive Grip in conjunction with a Great Weapon would allow a character to do extra damage by taking a penalty (disadvantage) on an attack. There is already a feat that fulfills this role: Great Weapon Master.

Great Weapon Master is also balanced in ways that Massive Grip isn't:

• The -5 attack penalty is cumulative with other circumstances that impose disadvantage; with Massive Grip, having disadvantage on an attack is no longer a penalty, because all attacks have disadvantage.
• The +10 damage bonus doesn't double with critical hits or other effects that modify die rolls. Anyone taking Massive Grip along with the Great Weapon Fighting fighting style gets more of a benefit, since they get more damage die rerolls.

Note also that there are no rules for how weapon damage scales with size. There are guidelines in the DMG for assigning damage scores to monsters, but they aren't rules.

A Medium character under the effects of the enlarge spell becomes Large, but their weapon damage doesn't double; instead it just increases by 1d4.

It seems like there are already balanced tools that allow you to build a goliath that makes clumsy, high-damage attacks with a big weapon; no need to introduce more.

Answer 2

As described this MAY be balanced for increasing a 2d6 weapon to 4d6

Methodology

Since you need to take a particular feat to use these new massive weapons I think it's fair to compare this balance-wise to other feats. To keep things simple I'm only looking at damage potential here; in play I would expect massive weapons to have RP effects that may be good or bad (Intimidating?, Hard to swing in tight places?, Rare?) but those are better evaluated through play testing.

Some feats for comparison

+2 to a stat: The basic option instead of taking a feat. Call it +1 attack and damage.

Dual Wielder: Changes out 1d6 attacks for 1d8. Call it +1 damage, +1 ac

Great Weapon Master: Harder to evaluate. If we assume a 16 str character using a Maul the attacks would be 2d6+3 for an average 10 damage. GWM lowers the odds to hit by 25% and adds 10 damage so... call it +5 damage

There are many other solid feats for increasing damage (Polearm Master comes to mind) but this is an acceptable sample.

New Feat: Massive Grip

Massive Grip increases damage from 2d6/attack to 4d6/attack, +1 strength, and constant disadvantage. The +1 strength could mean another +1 damage/attack and likely will for anyone optimizing their character.

Disadvantage is kind of like -5 to attack so lets go with that. This means Massive grip changes a str 15 character from 2d6+2/attack to (4d6+3)*0.8/attack. So that's going from 9dmg/attack to ~14dmg attack so call it +5 damage

Conclusion

Massive Grip is sort of comparable to Great Weapon Master. Now the problem is that you could take both and then it is likely (I haven't done the analysis/playtesting to confirm) that it would result in overpowered character.

Also since I only looked at damage I haven't considered how always making attacks at disadvantage (and thus not needing to worry about any second source of disadvantage) might skew things. Taking a page from Great Weapon Master perhaps changing the disadvantage to a straight -5 to attack would be sensible.

My suggestion would be to proceed with caution, disallow taking Massive Grip and GWM together, and see how this feels during play. In the end it's a houserule and as long as everyone at the table is happy with the result you're in a good place.