Ruby of the War Mage in 5e: This Is How It Works

Last Updated on January 22, 2023

An adventurer capable of weaving spells and sword together is a threat to take seriously and a fun archetype to play. Many classes in D&D 5e can do this.

However, the spellcasting rules can be tricky when mixing magic and martial attacks. A Ruby of the War Mage could solve that problem, though!

What Is A Ruby of the War Mage?

The Ruby of the War Mage is a common magic item from Xanathar’s Guide to Everything. This wondrous item allows the attuned user to use the weapon as a spellcasting focus for their spells. 

Here is the exact wording from the book: 

Ruby of the War Mage

Wondrous item, common (requires attunement by a spellcaster)

Etched with eldritch runes, this 1-inch-diameter ruby allows you to use a simple or martial weapon as a spellcasting focus for your spells.

For this property to work, you must attach the ruby to the weapon by pressing the ruby against it for at least 10 minutes.

Thereafter, the ruby can’t be removed unless you detach it as an action or the weapon is destroyed. Not even an antimagic field causes it to fall off. The ruby does fall off the weapon if your attunement to the ruby ends.

As a common magic item, the Ruby of the War Mage isn’t going to be the most exciting loot you find in a treasure hoard. However, this magic item can be a lifesaver for casting classes that often find their hands full.

By turning a weapon into a spellcasting focus, you can double-up the utility of a held item.  

Where you can find this item will depend on your game, but the Dungeon Master’s Guide lists common rarity items as being between 50gp and 100gp.

While that’s not exactly cheap for new adventurers, it isn’t as bad as other magic item rarities

You need to attune to this item, so it will take up one of your three attunement slots when in use. However, since this is a common magic item, you might find this before you find any attunement items worth your while. 

Still, the main benefit of this item is how it lets you interact with the spellcasting rules as someone who blends melee combat and magic spells. 

Ruby of the War Mage Spellcasting Rules

Why does a Ruby of the War Mage help out so much? The answer comes down to the spell component rules for spellcasting in D&D 5e

You see, every spell in the game has one or more components that you have to provide to cast that spell. These components break down into three groups: 

  • Verbal: The words of power you speak to cast the spell. 
  • Somatic: The specific hand gestures you have to create when casting the spell. 
  • Material: Any items, expensive or otherwise, that the spellcaster has to have to cast the spell. 

The rules state that a spell with an inexpensive material component (i.e. one that doesn’t have a gold piece cost) can be replaced with a component pouch or spellcasting focus.

Also, if you hold a spellcasting focus, you can use the same hand with the focus to create the somatic components of the spell.

However, this only works for spells with a material component.

If a spell doesn’t have a material component, you can’t use a hand-holding spellcasting focus to create the somatic components. You have to have a free hand instead. 

So, what happens if a character, like a Paladin or Ranger, wants to cast spells while using a sword and shield?

They could always take the War Caster feat, but that eats into the limited Ability Score Improvements the player gets over their character’s career.

Plus, unless you are a Variant Human or use the Custom Lineage rules, you won’t be able to start with this feat. That’s where the Ruby of the War Mage comes in. 

When you attach a Ruby of the War Mage to your weapon, it now counts as a spellcasting focus for your spells.

Now, if both of your character’s hands are full, you can still cast spells that have both a somatic and material component. 

Be careful with spells that only have a somatic component, though. The Ruby of War Mage still doesn’t let you cast spells that only have a somatic component with your hands full.

But, for characters that have their hands full with weapons and items in battle, this magic item can save a lot of item juggling and spell-component headaches when in combat. 

Who Benefits From A Ruby of the War Mage?

As we mentioned above, characters that have their hands full in combat stand to benefit from using a Ruby of the War Mage.

Classes such as Paladins and Rangers were on the developer’s minds when they came up with the item. 

Still, there are plenty of character classes and subclasses that might enjoy having this minor magical item on their character sheet. Here were some other examples we could think of: 

  • College of Valor Bards: Thanks to their weapon and shield proficiencies, College of Valor Bards could use the Ruby of the War Mage over an instrument to cast their combat buffs and healing spells. 
  • Melee-focused Clerics: Although you can get your holy symbol as a shield emblem, a Cleric using a shield without their god’s insignia could use a Ruby of the War Mage in place of a shield emblem for their spells. 
  • Eldritch Knight Fighters: Whether using a shield or dual-wielding, Eldritch Knights fighters can grab many Wizard spells with material components, which a Ruby of the War Mage fills in for. 
  • Hexblade Warlocks: Much like Valor Bards, a Hexblade Warlock could use a weapon, shield, and Ruby of the War Mage to overcome spellcasting component woes in combat.
  • Bladesinger Wizards: While they can’t use shields, some Bladesinger Wizards dual-wield their weapons, meaning a Ruby of the War Mage on one weapon could help them cast their spells without juggling items. 

In other words, almost any character that looks to combine martial prowess and magical flair could benefit from a Ruby of the War Mage, regardless of where their magic comes from.

Combined with the fact that this item is a common rarity item, this could easily end up in the hands of a player that needs it. 


The Ruby of the War Mage uniquely interacts with the spellcasting rules. So, questions about its use and function come up sometimes.

Here are the answers to the common questions we have seen out there for this magical item: 

What Does the Ruby of the War Mage Do?

The Ruby of the War Mage allows a spellcaster to turn a simple or martial weapon into a spellcasting focus.

This item is great for characters that blend martial and magical prowess that find their hands to be full in combat but still need a spellcasting focus for their spells. 

Does A Ruby of the War Mage Make A Weapon Magical?

Unfortunately, a Ruby of the War Mage does not make the weapon itself deal magical damage.

Instead, this magical item turns a weapon into a spellcasting focus. This change allows the weapon to be used for the somatic and material components of a spell. 


A Ruby of the War Mage is a magical item that lets you overcome some spellcasting headaches by combining a weapon with a spellcasting focus function.

With this, you can cast spells with both inexpensive material and somatic components with your hands full, as long as you hold the weapon the ruby is attached to.

If your character, or one at your table, struggles to juggle their items in combat, a quest or shopping trip to pick up this magic item could save the player a lot of headaches in the future!

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