Buster Weapons | New Rules for Dungeons & Dragons Fifth Edition

This is one that I’ve gotten requests for a few times in comments and direct messaging on Instagram. I thought it’d be a pretty quick build since I got the idea on what I need to do to create it while I was driving to pick DM Jack up from school today.

What is a buster weapon?

Supposedly, buster weapons–specifically the buster sword–got its origins from Final Fantasy VII. It’s the big ass broadsword that Cloud Strife used in the game. Its appeared in every Final Fantasy game since and become something of a staple in anime.

A buster weapon can be any larger-than-normal weapon. However, in Dungeons & Dragons Fifth Edition, the available weapons are either Medium or Small. And there’s no scaling up. Yet.

Playtest Content

The material here is presented for playtesting and to spark your imagination. These game mechanics are in draft form, usable in your campaign but not refined by
final game design and editing. They aren’t officially part of the game.

Constructive feedback is welcome and appreciated in either comments or social media. If you can give me a valid reason with examples why something is off, 9/10 I’m likely to make changes to the content and credit you for doing so. Otherwise, feedback without anything to back it up gets ignored (or at most a smile emoji like this 🙂 ) Thanks!

Design Notes

Here are my notes for this build.

Before the Build

In order to create these weapons, they need to be able to be big. Big usually means more damage. The problem with more damage, of course, is that more damage breaks the game, especially in the first tier.

The weapons in Dungeons & Dragons Fifth Edition are typically balanced by the fact that they are Heavy (meaning little dudes can’t use ’em effectively) or require two-hands.

Of course, we know larger weapons exist. The ogre greatclub deals 2d8 damage instead of the normal 1d8 damage for the weapon. Half-ogre battleaxes can deal 2d8 damage or 2d10 if wielded with two hands. The oni glaive deals 2d10 slashing damage when it is in its Large form. Another interesting entry is the fire giant’s greatsword. It deals 6d6 damage, four more dice than the regular greatsword. That tells me that the damage increases by a factor of two for each size category that it goes up.

Now, I don’t want to cheapen the rules. We want the buster sword to accomplish a few things here:

  • The buster sword should be modeled after a greatsword. Go big or go home.
  • It should be able to deal 4d6 damage in one swing. If it adds a +3 Strength modifier to the attack, that’s an average of 17 damage and a maximum of 27 with a lucky hit (or double that with a crit). If a great weapon fighting fighter wields it, that average damage goes up even more.
  • It has to be in line with what a 1st-level character is capable of doing. For example, a Barbarian with 16 Strength swinging a greatsword deals 10 damage on average and a maximum of 15. However, if the barbarian takes the Great Weapon Master feat, it can reduce its attack roll by -5 to add +10 to its damage bonus. So now we’re getting closer. That would make the average damage 20 and the maximum 25. Now it’s suddenly better than the 4d6 greatsword on average. So I think we can probably find something in the middle there using math.

According to Mike Mearls, a character has, on average, a 60% chance of hitting a monster with an attack, or a 40% chance to miss. With advantage, that turns into an 84% chance to hit and 16% chance to miss. And with disadvantage, it’s only a 36% chance to hit or 64% chance to miss.

If we multiply those numbers by 20 (the d20), we can determine that the virtual bonus and penalty for each is as follows:

  • Advantage gives a virtual 4.8 bonus on attack rolls.
  • Disadvantage gives a virtual 4.8 penalty on attack rolls.

Now, what you’ll notice right away is that those numbers are pretty darn close to the -5 penalty that Great Weapon Fighter gives in exchange for +10 in damage. So I think that if we give the user of a buster weapon a permanent disadvantage on their attacks using the feat, that will help balance out the weapon.

Let’s compare the two weapons’ damage output. I’ve multiplied the average damage of the weapon by the hit probability.

  • Greatsword (2d6 + 3) with no disadvantage deals an average of 6 damage per turn (10 x 0.60).
  • Buster sword (4d6 + 3) with disadvantage deals an average of 6.12 damage per turn (17 x 0.36).

Boom, pretty close!

After the Build

Looking at the heavy weapon property, it pretty much knocks it out of the park in terms of what I need buster weapons to do. Basically, a buster weapon gives a constant disadvantage to the attack. That means I don’t need to offer a feat for a creature to gain proficiency in it. They can just learn it as a martial weapon. The weapon property will supply the disadvantage.

For weight and cost of the weapons, I multiplied everything by 4. I’m not totally sure that’s right (some physics major will surely correct me), but if it’s good enough for barding, it’s good enough for me.

So then I just used the feat to reverse the method of the Great Weapon Mastery feat: you give up damage output the weapon normally does in order to not have disadvantage when making an attack with the weapon. Plus, it gives you a bonus against shields.


Optional Weapon Rules

At your GM’s discretion, your campaign may use the following optional rules and weapons.

New Weapon Property: Buster Weapon

Small creatures cannot use buster weapons. And Medium creatures have disadvantage on attack rolls with buster weapons. A buster weapon’s size and bulk makes it too large for a Medium creature to use effectively.

New Weapons

Name Cost Damage Weight Properties
Martial Melee Weapons
Buster Axe 120 gp 2d12 slashing 28 lbs Buster, two-handed
Buster Club 1 gp 2d8 bludgeoning 40 lbs Buster, two-handed
Buster Hammer 60 gp 4d6 bludgeoning 40 lbs Buster, two-handed
Buster Sword 200 gp 4d6 slashing 24 lbs Buster, two-handed


New Feat: Buster Weapon Master

Prerequisite: Strength 16 or higher

You have practiced extensively with extremely large weapons, gaining the following benefits:

  • You gain a +1 bonus on attack rolls with a buster weapon against any Medium or smaller target using a shield. Your large weapon easily overcomes the defense provided by shields.
  • Before you make a melee attack with a buster weapon that you are proficient with, you can choose to make the attack without the normal disadvantage imposed for handling a buster weapon. If the attack hits, you take a -10 penalty to the damage roll (minimum of 1 + your Strength modifier).


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Next: Monk Way of the Animal

Art by Square Enix.

22 thoughts on “Buster Weapons | New Rules for Dungeons & Dragons Fifth Edition

  1. I like this a lot. Thanks! My one criticism I’d give is to maybe change the wording of it to include any weapon that’s one size category too large for you to normally wield, so that a small character could use the same feat to wield a medium sized weapon and gain the same benefits. For example, I have a kobold barbarian in Pathfinder that I want to convert over into DnD, and his signature weapon is an oversized hammer (when compared to his actual size). This feat would be really handy for him, at least amongst DM’s willing to run it.

    1. After I wrote this, someone pointed out that the DMG actually already states pretty much what I wrote haha. The only thing I added was the feat that allows for improved attacks. 🙂

  2. Hi! very nice! Is it possible to simply use a Buster weapon AND the GWM feat, attacking with Disadvantage AND -5 on the attack roll, damaging with the buster weapon doubled dice AND the +10(GWM) all at the same time ?

    Also, i feel like the feat is a little bit weak, considering that GWM gives a way better bonus (one more attack on a crit and on a kill). If you compare 2 fighters, one using a GS with GWM and one using a Buster GS and your custom feat i think the second fighter is a bit weaker. Id personally use the Buster weapon and switch to another weapon when i want to boost my chances to hit instead of taking the feat. I would also take GWM + buster weapon vs low AC enemies and id completely switch to another weapon for high AC enemies instead of taking the feat.

    So i think you could tweak the feat a little bit, my humble opinion.

  3. Overall I like this a lot! I agree with the approach to handling over-sized weapons, especially given its pretty much what is already done with small creatures attempting to use heavy weapons and who doesn’t like the idea of wielding a big a** buster sword???

    That said, I agree with Swem on the feat. I appreciate the idea of composing it similarly to GWM, but the problem is it doesn’t consider scaling as levels increase. GWM gets progressively better and better with scaling as the -5 to hit becomes less harsh of an impact with higher to hit via stat/proficiency/magical item progression. Inversely, the buster feat gets *less* good as removing the disadvantage becomes less concerning as your to hit increases. Also the +1 to hit against a medium or smaller creature with a shield, imo, is pretty lack luster and decidedly less “fun” from a player’s perspective than what GWM offers and suffers from the same scaling issues. As level increases, that +1 becomes less and less impressive, doubly so if what you’re fighting has access to magically scaling shields of their own.

    I am not certain where the appropriate balancing would be, but given the nature of striking with this enormous weapon, why not have some means of bypassing the shield altogether? Perhaps add a carrier effect that when attacking a medium or smaller creature wielding a shield, a successful attack includes a contested athletics/acrobatics check to disarm them of the shield entirely, or at very least render it useless by knocking it aside for the remainder of your turn, exposing them and thus effectively increasing your to hit temporarily for any extra attacks you can make that turn.

    Depending on how many extra rolls you want to avoid, you could either give a static DC or 8 + prof + STR(only not saying athletics here because technically you could have proficiency in the weapon and not in athletics but I think the argument could be made for it to just be 8 + athletics), simply set the opposed check against whatever the successful attack roll was, or have a separate straight contested athletics check a la grapple.

    Beyond that, considering that the removal of disadvantage would become less used over time, and the constant state of disadvantage makes a crit next to impossible compared to a straight roll weapon attack(.25% vs 5%), I think some other additional function would serve the nature of using such a weapon. Thematically, I think such a weapon screams big sweeping attacks. It would not be an immediate effect at level 1, but something situational building off of extra attack could fit the bill. Something to the effect of “If you could perform multiple attacks via your attack action, you may instead use the attack action to perform a sweeping strike, making a single attack against all creatures within 5ft of you in a single blow.” It would have to be somewhat situational as you would have to watch for allies, but what would be more satisfying than wading into battle with an 8 ft blade and getting to potentially cleave down an entire wave of enemies?! In that respect, if you left the current down scaling of power to remove the disadvantage to use in conjunction with this once you have extra attack, you could land a potentially smaller amount of damage against a larger number of foes.

    Anyway, that’s maybe way more input than you wanted, but I had some time to kill and my brain went to town with how else to implement or build off what you had here. I enjoy the posts! Cheers!!

  4. If you use the feature from the feat and lose the disadvantage, can you apply an advantage if you spend inspiration or otherwise gain it?

      1. technically they don’t need to stack since there is only one Advantage involved. by RAW of the feat, you *negate* the disadvantage so the weapon makes a normal attack, so by world of the law advantage would apply in combination with the feat.

  5. What about making it so that medium creatures with a strength below 20 have disadvantage, So that if a PC has maxed strength they can use this without the disadvantage, or just have disadvantage on opportunity attacks with that weapon?

    1. Possibly, although some DMs allow dice roll variants. At the end of the day whatever the DM says goes so just ask the DM 😄

      1. I’m coming from a DM Stand point I gave one of my PCs a buster sword but after awhile one of my PCs (who has been DMing a lot longer than me) was worried about it being too overpowered compared to the rest of the party, this was a solution I came too. Just trying to make my players happy and enjoy a big as sword to play with.

  6. A character with a greatsword has a -5 to hit in order to deal an extra 10 damage if they take the feat, which makes the sword a bit better in terms of average damage than a buster sword with no feat. This makes sense to me because if you invest a feat this should give you an advantage over those who do not.

    The tricky thing about the feat presented for buster swords is that it drops the average damage below what a regular greatsword with no feat is capable of. A character using a buster sword with the feat actually does 3 lower average damage than a greatsword wielder with no feat (and an identical chance to hit unless the opponent has a shield).

    I believe that a -5 penalty to damage would be more balanced. This would lead someone with this feat to only do 2 more average damage than someone using a greatsword and would give the +1 bonus to attack against shield-using enemies. It leads to a character wielding a buster sword with the feat having a relative advantage (rather than a disadvantage) over someone who is using a regular greatsword without the feat.

    Otherwise a character is mostly paying for a feat that only allows them to nerf their buster sword in situations where they cannot afford the disadvantage more so than actually providing an advantage.

  7. cool concept, for a player I built a full blade a while back and sort of went halfway requiring very high strength to wield without disadvantage (17) we were using standard array and they were playing a human so they had to wait till level 4 to use it without disadvantage. I did go halfway though so 3d6 instead of 4d6.

    When building out the feat we need to remember that we are paying an opportunity cost and that we may wish to build in some additional features. Most feats are designed with a benefit specifc to the weapon and a second benefit that anyone could use. In the example of great weapon master we have -5 +10 for attack and damage with a heavy weapon, and on any attack that you drop someone to 0 or crit you can make a second attack as a bonus action.

    I agree that giving disadvantage is a good move to balance the effectively double damage, my advice would be to consider having the feat take away disadvantage, but provide another low accuracy ability for instance a cleave like ability, -5 penalty to attack but the attack targets two creatures that are within 5ft of each other. Issues of course are that a variant human could have this feat at level 1 and be toting enough fire power to level most enemies but they had to spend their feat on it which is most of their specialization. Otherwise you earliest gain is level 4

      1. If it was as low as an 18 to clear the disadvantage it would become the clear best option out there for every str based melee build. I think you could justify it by allowing it at 21+ to effectively be at the str of giants though. This also would make it only Possible by acquisition of some sort of magical item to exceed the 20 stat cap.

      2. I’d say the large nature of ogres lets them handle it when they otherwise wouldn’t be able to. I like the 21+ idea.

  8. I have a player who is interested in wielding a larger than normal weapon which could do more damage as well. We definitely considered disadvantage on the attack roll because mechanically it makes sense that if you deal more damage than normal, you should hit less often. The reason I don’t like this solution is the impact it has on the “fun” factor.

    Not hitting something in DnD is a lousy feeling. Not hitting something turn after turn in combat is really frustrating. And in DnD it happens a lot already because of how the game is balanced. Especially at low levels.

    So the solution I came up with was rather than making it harder for the guy with the big weapon to hit, I made him easier to hit. Give him a penalty to AC whenever he wields the larger than normal weapon.

    Now he gets to have fun wailing on baddies dealing extra damage but he also takes more damage. It makes combat more dramatic because now he is more likely to need healing. He has to decide if certain fights necessitate using a smaller weapon to preserve his AC. We get to add a layer of complexity that forces the all the players to have to make even more strategic decisions.

    From a RP perspective I justify it by saying that the heavier weapon is unwieldy and makes you less able to dodge effectively.

  9. Just asking, but could we add like a shield type function to ut as well, because technically its broad enough to block attacks just like shield but since its a bit unwieldy we could just do like a +2 to AC or halved physical type of damage if the PC goes into a defensive stance or something ?

  10. disadvantage on all attack rolls is not worth taking for any benefit. a sword that deals 6d6 would still suck at that rate

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