D&D 5E Oversized and undersized weapons in 5e

[jgsugden]

I would also say that (on top of disadvantage) you do not generally have proficiency in a weapon that is not sized for you. You might gain it through the weapon master feat, but saying you're proficient with something you are not designed for you to use is a stretch for me.

However, if a PC were to take a greatclub from an ogre that deals 2d8, then dropped it, then were enlarged to be large size ... I'd allow them to use it proficiently if they were proficient in greatclub and deal the 2d8 damage.

Regardless, if you're going to get into shapechanging trickery, there are limits. There was a fighter/druid in my campaign that wildshaped into a giant ape ... and proceeded to try to use a weapon dropped by a giant. I ruled that he would not be proficient as the weapon was not designed for the hand of the ape, but for a more humanoid hand. While ape hands are more humanlike than almost all other creatures, they are still different (short thumbs, longer fingers).

 

[Crimson Longinus]

How the weapon size rules work for monsters make perfect sense. There are balance reasons why they don't work that way for PCs, but then things stop making sense. Why is ogre's large longsword doing 2d8 damage, but PCs longsword enlarged by a spell is doing just 1d8+1d4 damage? And is there anything stopping a PC picking up that ogre's inexplicably better large sword and using that instead? I don't think so. It didn't use to be such a big deal, as it was mainly the enlarge spell that did this, but now there are several subclasses that allow the character routinely become large or even huge.

 

[dave2008]

Actually. the DMG says (In the Creating a Monster section):

"Big monsters typically wield oversized weapons that deal extra dice of damage on a hit. Double the weapon dice if the creature is Large, triple the weapon dice if it’s Huge, and quadruple the weapon dice if it’s Gargantuan. For example, a Huge giant wielding an appropriately sized greataxe deals 3d12 slashing damage (plus its Strength bonus), instead of the normal 1d12."

Are these rules laid out in the PHB/Basic, or did you reverse-engineer them from MM entries?

Not laid out exactly, the small creature thing and enlarge spell effects yes. The monster large size weapon thing is just how every instance in the MM is handled.

I do believe it was talked about in a tweet or article at some point, and I am sure it will be covered in the DMG come December.

 

[Charlaquin]

(Wait, this thread was revived from 10 years ago?)

Always check the dates of threads whose titles are simple rules questions that can be answered with a citation from the books. They’re almost always from the first year or so of the edition’s life.

 

[Vaalingrade]

How the weapon size rules work for monsters make perfect sense. There are balance reasons why they don't work that way for PCs, but then things stop making sense. Why is ogre's large longsword doing 2d8 damage, but PCs longsword enlarged by a spell is doing just 1d8+1d4 damage? And is there anything stopping a PC picking up that ogre's inexplicably better large sword and using that instead? I don't think so. It didn't use to be such a big deal, as it was mainly the enlarge spell that did this, but now there are several subclasses that allow the character routinely become large or even huge.

How do they determine in-universe how many dice of damage the ogre's sword does?

 

[fluffybunbunkittens]

Maybe you need to be as strong as a giant to use their weapons, and they all just happen to start at Str 21+, so it's more like a combo deal with belt of giant strength or something (which render your basic Strength score completely moot, making it wasted points for your presumably strong character concept, but that's a different thread topic).

Of course, that still wouldn't deal with Ogre 2d8 greatclubs... but that particular weapon seems like an okay option to have, needing Enlarge (of which there are many sources now) to use your weapon which only gets the Push weapon mastery anyway. Just don't give ogres other weapons?

I would also say that (on top of disadvantage) you do not generally have proficiency in a weapon that is not sized for you. You might gain it through the weapon master feat

Are you saying it's like it's some kind of an exotic weapon?

 

[Blue]

There are monster-only rules for weapons for different sized monsters in the DMG. They conflict with PC rules so we know they cannot be PC-facing, and they are primarily a tool to get the monsters to do damage within the appropriate damage range as specified by their CR.

There are no rules at all about wielding weapons that are oversized or undersized for a creature's size.

PC-facing there are no weapon size rules at all. There is no difference between a halfling's dagger and a goliath's dagger, and the halfling and goliath could swap those daggers without any mechanical ramifications. Same is true of armor or any other equipment as well. There are rules for a keyword on a PC weapon that makes it give disadvantage to a small character, but no rules for example to make a halfling sized greatsword.

 

[Crimson Longinus]

There are monster-only rules for weapons for different sized monsters in the DMG. They conflict with PC rules so we know they cannot be PC-facing, and they are primarily a tool to get the monsters to do damage within the appropriate damage range as specified by their CR.

There are no rules at all about wielding weapons that are oversized or undersized for a creature's size.

PC-facing there are no weapon size rules at all. There is no difference between a halfling's dagger and a goliath's dagger, and the halfling and goliath could swap those daggers without any mechanical ramifications. Same is true of armor or any other equipment as well. There are rules for a keyword on a PC weapon that makes it give disadvantage to a small character, but no rules for example to make a halfling sized greatsword.

I disagree that those rules are not meant for PCs. We cannot infer that. There specifically are rules that say what happens if you are trying to use an oversized weapon. This is a situation that is highly unlikely to come up for the monsters, but definitely something a PC might try.

 

[Blue]

For those that think the weapon's size doesn't impact the weapon's damage, a human could wield a sprite's tiny longsword and deal 1d8 damage instead of 1 damage. Alternately, I propose that the weapon's size does matter (DMG p277), and despite the Enlarge/Reduce says that it deals an extra 1d4 damage, I don't believe that this extra damage overrides the inherent damage increase from a weapon that was increased.

Those rules are for getting monsters to do the right damage range for their CR. These are other monster-facing rules only, like Refresh for abilities.

We know for a fact that they are not PC facing as they contradict the PC rules for weapons. For example, a small creature would have disadvantage using a short sword sized for a medium creature using those rules, and that is not true. It is also clear given the low feature/spell level for Enlarge that the damage rate climbs at a rate unable to be matched elsewhere and isn't intended for PC usage.

To sum up: the rules in the DMG are clearly in a Monster modification section, and are presented in the context of getting monsters to do the damage that is correct for their CR, and contradict some PC-facing rules. They are not intended nor presented to be general usage weapon size rules.

EDIT: @Crimson Longinus just saw your post, this answers that as well.

 

[jgsugden]

...Are you saying it's like it's some kind of an exotic weapon?

If you want to harken back to older editions - sure. Try swinging an actual bludgeoning weapon and then swinging a big old tree limb. When the 'weapon' is not designed to be held by someone like you, it is much harder to use ... but if you learn to adjust for those differences, it might be possible to get proficient with it.

We need to consider that going from a d12 greataxe to a 2d12 greataxe from a minotaur at the cost of one feat is a lot of extra damage. I'd allow it if a PC was enlarged and picked it up with no feat cost (although I would negate the usual +1d4 for the enlarged weapon). I'd allow a medium sized PC to use it without penalty if they took the weapon master feat to do so - but they're unlikely to find axes of that size down the road. While they might have one enchanted, they're unlikely to find a large magical greataxe later in the campaign as an upgraded magic weapon. Further, I might rule it is hard to use in narrow places.

The game is not that fragile. A fighter that can attack for 2d12 rather than 2d6 after spending a feat will not shatter the game.