One of the randomly obtainable runes on a Moonblade (DMG, p. 217) is:

The moonblade functions as a vorpal sword.

A regular vorpal sword has a +3 bonus to attack and damage rolls.

If you get the vorpal rune, would the Moonblade also benefit from the inherent +3 bonus that a regular vorpal sword gives? The same question goes for the defender rune.

Note that a Moonblade comes with an initial +1 bonus, but whether that bonus would stack on top of the (possible) vorpal/defender bonus needs a separate question if this one is answered as "yes".

  • \$\begingroup\$ I think the defender part should come out of this question. Neither answers currently even deal with it and it's a different effect entirely. Though very similar I'm not sure they should be combined. \$\endgroup\$ Aug 25, 2018 at 1:23

2 Answers 2


No, the Moonblade probably does not get the +3 from Vorpal Weapon

There are no rules or designer clarifications that answer this question beyond a doubt. However, there is a very compelling case to be made by looking at the two options through the lense of the other runes and features of the Moonblade to see which interpretation better fits in with the rest.

Giving the Vorpal rune +3 would make it much more powerful than and very different design-wise from all the other runes

No runes directly duplicate effects of other runes

If the Vorpal rune were to give a +3 bonus it would directly overlap with another rune on the Moonblade which says:

Increase the bonus to attack and damage rolls by 1, to a maximum of +3. Reroll if the moonblade already has a +3 bonus.

This kind of overlap is something none of the other runes do at all. But this interpretation would mean the Vorpal rune completely overlaps this rune to the point of making it useless if the Vorpal rune is obtained. This is also something none of the other runes do: make another rune unusable.

No runes are as powerful as 4 runes combined

Not only is the Vorpal rune duplicating the effect of the +1 rune, it is doing so in a way that is 3 times better than the other! It doesn't make sense for one rune to give a simple additional +1 bonus property but then to have another rune automatically give the Moonblade a +3 bonus in one go. You would literally have to get the first rune 3 times to even get part of the power of the Vorpal rune. And I say "part of" because...

No rune adds more than one effect per rune

The Vorpal Weapon isn't just +3, it would also add a really powerful effect. Note that every other rune adds a single effect to the weapon. Why would the Vorpal rune function any differently? It even says in the description:

Each rune beyond the first grants the moonblade an additional property.

When taken together, I think this makes a very compelling case for saying that taking the Vorpal rune only grants you the powers of a Vorpal Weapon but not its +3 bonus.

tl;dr Essentially we have two interpretations, one that would make the Vorpal rune more powerful than 4 other runes combined and one interpretation that makes its power roughly equal to the other runes. And it just makes sense to conclude that the second, more reasonable interpretation is likely what was intended here.

And until we get designer clarification I think that is the best I can do.

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    \$\begingroup\$ You could include the section in the DMG about building magical items. The recommended maximum bonus being +4 even though there are no weapons or armor with that bonus in the standard rules. \$\endgroup\$
    – Slagmoth
    Aug 24, 2018 at 19:09
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    \$\begingroup\$ What's the argument for the bonuses having to be balanced? Since it's a random effect, it seems just as likely that there should be disparity between the outcomes. Compare/Contrast to the most extreme example, Deck of Many Things. \$\endgroup\$ Aug 24, 2018 at 19:52
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    \$\begingroup\$ @screamline you are only focusing on power, but I make other arguments besides just that. Regardless though, I'm pretty happy with this answer as is. So unless you have some suggestions for me to improve this answer, I would consider putting your thoughts into an answer of your own instead. \$\endgroup\$ Aug 24, 2018 at 20:31
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    \$\begingroup\$ @Winterborne you are only focusing on power, but I make other arguments besides just that. Also, looking at another item whose defining characteristic is the wildly imbalanced and random distribution of power is not really a helpful comparison I think. Regardless though, I'm pretty happy with this answer as is. So unless you have some suggestions for me to improve this answer, I would consider putting your thoughts into an answer of your own instead. \$\endgroup\$ Aug 24, 2018 at 20:33
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    \$\begingroup\$ The argument is certainly compelling in the case of vorpal weapon, as ignoring slashing resistance and the natural 20 effect are powerful enough in and of themselves. But I'm not sure the same applies to defender, where the lack of a +3 bonus (without additional +1s from other runes) makes the ability significantly weaker. \$\endgroup\$
    – Wlerin
    Aug 24, 2018 at 23:23

Yes, the Moon Blade gets all the benefits of a Vorpal Sword

As you yourself quoted, the DMG states that when you acquire that rune, your moonblade functions as a vorpal sword. Vorpal sword does three things, a +3 to hit/dmg, ignore slashing resistance, cut off a head on roll of 20. That means so does your moonblade.

But isn't that too strong?

No, not really. First of all, a moonblade is a Legendary item. These things are meant to be rare, desirable and highly powerful compared to a regular magic item. Second, it's not at all easy to acquire the runes.

If the blade accepts you, you become attuned to it and a new rune appears on the blade. You remain attuned to the weapon until you die or the weapon is destroyed. (DMG 217)

The blade only acquires a new rune when it gets a new master. So, unless your DM plans to continue the campaign through the lineage of your character, you're only ever getting one additional rune to what the sword comes with.

The other runes(at least 2) are decided by the DM.

A moonblade has one rune on its blade for each master it has served (typically 1d6 + 1). The first rune always grants a +1 bonus to attack and damage rolls made with this magic weapon. Each rune beyond the first grants the moon blade an additional property. The DM chooses each property or determines it randomly on the Moon Blade Properties table. (DMG 217)

So, right off the bat, you can see that the rules allow the DM to set the power level of any Moonblade that appears in their game. They can straight out choose the existing runes. But even if they do not, the rune table makes it difficult to roll up a completely broken sword.

Defender can only be acquired by 2/100 results.

Vorpal Blade can only be acquired by 1/100 results.

Elfshadow can only be acquired by 1/100 results.

In fact, rolls on 1-80 only give you a small boost of power, such as a +1 to the weapon, or a random minor property. The chances of rolling a truly broken weapon are extremely minuscule, and also require the DM to choose to roll the traits, rather than manually assigning them.


The Vorpal Blade rune seems powerful because it is. It is difficult to acquire by design, and almost impossible to be abused without DM's direct approval, since they have ultimate say over what runes already exist on your Moonblade.

  • \$\begingroup\$ It is within the item description that there had been at least one previous owner, so having a rune already in play is not beyond the power level of this item ... but that will be a DM by DM call. \$\endgroup\$ Aug 25, 2018 at 15:06

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