D&D 5e: Rune Knight Fighter Guide

D&D 5e: Rune Knight Fighter Guide

Role in the Party

A warrior stands, clad in shining steel, against a veritable sea of foes. They swarm upon him, crude weapons flashing through the air, but he stands, indomitable. With a shouted word of power, the tide of bodies is thrown back as the warrior doubles in height. A second shout ignites the runes, so painstakingly inscribed, on their tree trunk length sword. A single swing is all it takes to break the enemy line and turn the entire battle. 

Front line warriors who enhance their equipment with many passive and active abilities using Runic inscriptions and also possess the power to turn into giants several times per day, Rune Knights are solid tanks and powerful damage dealers that can act as a capable anchor to the front lines of a party’s composition, or focus instead on disabling and killing their enemies. This guide breaks down the subclass abilities, feat and skill choices, possible build paths, and more.   





The Rune Knight Fighter subclass is found in Tasha’s Cauldron of Everything. Click here to pick up your own copy of Tasha’s Cauldron of Everything!

Rune Knight Features

Bonus Proficiencies: At 3rd level, the Rune Knight gains proficiency in Smith’s Tools, as well as the Giant language. 

Rune Carver: From 3rd level, the character learns to carve the magical language of runes into their gear to empower themselves. 

The character learns 2 runes from a small list. The number of runes known increases to 3 at 7th level, 4 at 10th level, and 5 at 15th level. 

Runes have to be inscribed on a piece of gear. Realistically, this has no effect unless your GM is insistent on trying to steal it on purpose. Each rune has a passive effect, and can also be invoked for a stronger, active effect. 

Rune Knight Runes:

  • Cloud Rune: Passively gain Advantage on Sleight of Hand and Deception checks. Invoke the rune and spend a reaction to cause an attack that hits a target within 30ft to hit any other target within range
    The passive effects are useful for a particular sort of character, but many Rune Knights won’t have those skills. The active effect, on the other hand, is incredibly powerful, as well as hysterical. Forcing an enemy to hit their friends, or themselves, without any sort of save or check, plus saving an ally from that damage, is amazing. 

  • Fire Rune: Passively gain Expertise in the use of all tools. (You have Smith’s Tools already, and remember that Thief’s Tools exist.) Invoking the rune after hitting an enemy deals 2d6 Fire damage and forces a STR save. Failure Restrains the target and deals another 2d6 damage every turn. 
    Another Roguish passive here, though it’s also useful for crafters. The active effect is incredibly strong if it goes off, and can often end encounters by itself, but many enemies will have a good Strength save.  

  • Frost Rune: Passively gain Advantage on Animal Handling and Intimidation checks. Invoking the rune as a bonus action gives the Rune Knight +2 on STR and CON saves and checks for 10 minutes. 
    These are mediocre bonuses. The skills are niche, and the invoked ability is such a small boost that it’s mostly not worth it. 

  • Stone Rune: Passively gain Advantage on Insight checks, and 120ft darkvision. Invoking the rune forces a WIS save on a creature within 30ft. Failure charms the creature reduces its speed to 0, and Incapacitates it, for 1 minute, or until it passes a save on its turn. 
    This is fantastic. Insight is a skill the Rune Knight might take for social encounters, Darkvision is useful if you don’t have it, and 120ft is double the standard racial Darkvision range. 
    The Invoked effect is even more powerful. If it goes off, it’s an absolute disable on one enemy, and, interestingly, doesn’t specify that damage switches off the effect, which many abilities like this do.

From 7th level, the Rune Knight can also choose from two further runes: 

  • Hill Rune: Passively gain Advantage on poison saves and resistance to poison damage. Invoke the rune as a bonus action for resistance on bludgeoning, piercing, and slashing damage for 1 minute. 
    The passive effect is genuinely kind of lame, but switching on damage reduction for a minute is an incredibly strong ability, especially at the relatively low level you can get this from. 

  • Storm Rune: Passively gain Advantage on Arcana checks, and gain immunity to being surprised. Invoking the rune lets you force an attack roll, saving throw, or ability check made within 60ft of you to be made with Advantage or Disadvantage, as you choose. 
    The passive effect is aggressively fine, though surprise doesn’t come up often in a lot of campaigns. The invocation on the other hand is incredibly handy to have, with near infinite uses in and out of combat, though it’s not quite as impactful as many of the other options. 

Giant’s Might: Also from 3rd level, the character can call upon the might of the giants to imbue themselves with power. 

As a bonus action, the character gains the benefits below for 1 minute:

  • The character becomes Large sized, as does everything they’re wearing. If there’s no space, the character doesn’t change in size, but still gets the other benefits. 

  • The character has Advantage on Strength checks and Strength saving throws.

  • Once per turn, after hitting with a weapon or unarmed attack, it deals an extra 1d6 damage.

  • The ability can be used a number of times equal to your proficiency bonus, and all uses come back on a short rest. 

This is a fantastic ability that defines the strength, and the feel, of the character. Shifting into a Large form in most of your combat encounters is a big deal. Deal bonus damage and gaining Advantage on Strength checks almost feels like budget Rage. Taking up more space also allows you to block off a serious chunk of the battlefield, really allowing the character to lean into its role as a defense oriented bruiser.  

Runic Shield: From 7th level, you can use the power of your runes to protect your allies, as well as yourself. 

When you see another creature within 60ft get hit by an attack, you can spend your reaction to force the attack dice to be rerolled. This can be used a number of times per day equal to your proficiency bonus. 

This is an incredibly powerful ability, especially if you save it to switch off critical hits or attacks that would otherwise kill an ally. The fact that it doesn’t take any of your existing resources is also incredibly nice, as is the fact that this scales up in uses as you level, so it’s always going to stay relevant.

Great Stature: From 10th level, the bonus damage from your Giant’s Might feature increases to 1d8. This is a small bonus to damage, and one you’re probably not going to notice often.   

The character also gains 3d4 inches in permanent height. This has no appreciable benefit, but it is funny. So there’s that. 

Master of Runes: From 15th level, the Rune Knight learns to draw more power from the runes they inscribe. 

  • Now, each rune can be invoked twice instead of once

  • All invoked runes also refresh on short rests as well as long rests

A literal doubling in the number of runic invocations is a monstrous boost in power. And that’s at a minimum. With short rests, you could use your runic invocations in every single encounter you have. 

Runic Juggernaut: At 18th level, the power of the giants truly runs through you. The damage from Giant’s Might increases again, to 1d10, and when you transform, you can choose to increase to Huge size, as well as gain an extra 5ft of reach. 

This is incredibly powerful. The sheer amount of space control you gain from being Huge with extra reach allows the character to utterly control the battlefield. The bonus damage is good, and there are other benefits, for example, being able to grapple with equivalent sized monsters. 


The Rune Knight is an incredibly powerful subclass. Its abilities kick in early; the class gains two major abilities at level 3 alone, each one of which would be good enough to justify the subclass. 

Calling on the power of the runes gives a Rune Knight a ton of flexibility in how they choose to do battle. Each one offers passives that can make the character genuinely good at skills and other out of combat situations, which is rare for a Fighter, as well as adding a whole lot of combat power into the bargain. 

But also at the same level, the Rune Knight gains the Giant’s Might ability, which lets them grow in size, as well as offering many of the benefits of the Barbarian’s Rage ability. 

Both of these abilities are character defining, and as the character levels, they only grow stronger. Learning more runes and the ability to use them more often can mean using multiple runes per combat encounter ceases to be an issue, and Giant’s Might scales with proficiency, so by mid-levels, it’s almost impossible to run out. 

Add in some defensive abilities, the ability to comfortably use any style of fighting, plus all of the standard Fighter class abilities for a spectacularly effective class that’s strong on base value, and can be tweaked into an absolute monster with feats and multiclassing.  


While it’s packed with good things, the Rune Knight does have a few weaknesses. 

Firstly, your core abilities turn you into a big threat, but also make you a big target, and there’s nothing in the kit that keeps you alive, only your friends. A Rune Knight either needs to invest in some sort of defense, or trust in their party to keep them alive. 

Second, Rune Knights aren’t the best class for ranged combat and lack many effective options. The class abilities heavily favor melee, and there’s no spellcasting here. Find a way to fix this, even just by packing a bow. 

Lastly, at early levels, the Rune Knight might struggle with resources. While you might get two abilities at level 3, each one only gets two uses, and it’s easily possible to use one of two stocks of Giant’s Might and both your Rune Invocations in a single encounter. 

As you level, this becomes much less of a problem, but until you hit around level 7, it’s better to play more conservatively, and save abilities for big fights. 

Best Race Options

Goliath: Perfect stats, resistance to cold, and a once per rest damage reduction ability are great things to have. Goliaths also gain free proficiency in Athletics and can lift and carry things as if they’re one size larger. Just in case you wanted to suplex that dragon off a cliff. 

Metallic Dragonborn: Your choice of stats and an elemental damage resistance start us off. All Dragonborn gain powerful breath weapons, which shore up your inability to deal AOE damage and only replace a single attack roll. All Dragonborn are good, but Metallic is best for damage, Gems can fly, and Chromatic are more defensive.   

Bugbear: Darkvision, Stealth proficiency, and bonus damage in the surprise round play into some of the more subtle aspects of the subclass. Powerful Build increases your carrying capacity. But Long Limbed is by far the strongest thing here, increasing your melee weapon range by 5ft, which, when you’re a Large sized creature, is berserk. 

Choosing the Right Skills

The single most important skill for the Rune Knight is Athletics. You’re a fantastically effective grappler with a built-in boost to the skill, which also governs all of your physical feats, so make sure you have proficiency in it. 

Perception is also very important, helping you find secret doors and not get stabbed by hidden enemies. 

No other skills are vital, so choose things that suit the character. Social aspects can be governed by a single skill, Persuasion. Taking Survival turns the character into an outdoorsman, and Stealth can be handy in certain campaigns. 

Fitting Feats

Tavern Brawler: A boost to the stats you like is great, as is proficiency with Unarmed Strikes, a boost to their damage, and also proficiency with improvised weapons. (That’s … literally everything you can pick up.)

But the big deal here is for grapplers. Every time you hit with an unarmed attack or improvised weapon, you can spend your bonus action to grapple. Remember, this is a subclass that can turn Large and gain Advantage on Athletics for grappling checks at will. You’re one of the best grapplers in the entire game, so if you want to do it, this is the way. 

Shield Master: For the same reason as Tavern Brawler, Shield Master is an excellent feat for the Rune Knight. Spending bonus actions to knock enemies prone becomes a big deal when you can grant yourself Advantage on the check. 

Extra defense is also nice to have, especially for a character that’s so big that they’re going to be eating all of the AOEs that are thrown out. 

Great Weapon Master: If you want to deal damage, GWM is one of the best ways to do it. You’re massive, with increased reach and threat range. Park yourself directly between the biggest group of enemies and smash holes in everything that gets close to you. 

Optimal Backgrounds

Sailor: Perfect skills for the class. Water Vehicles and Navigation Tools turn you into a literal Viking. 

Guild Artisan: Two social skills, another Artisan’s Tool, and a language is a great grab bag for the character. 

Urchin: This is for builds that are leaning into the passive skills of the Rune Knight’s runes, and who might invest in mental stats a little more. Two sneaky skills are great. Two toolkits that help with subterfuge, including the all-important Thief’s Tools, are better. 

Multiclassing Options

Lore Bard: Bards are a fantastic class that offers a ton of spellcasting power and utility to the build. Just a couple of levels help spin the character into a skill monkey and utility caster. 

But we’re here for two things. Expertise, which we’re putting straight into Athletics. (And one other skill.) Cutting Words is the key ability of the Lore subclass. Between the two of these, the character becomes one of the best grapplers in the entire game, with Advantage and Expertise in the skill, and the ability to directly debuff the enemy’s rolls. Between all this, it’s basically impossible to fail the check. 

Ancestral Guardian Barbarian: Barbarians and Fighters go hand in hand, happily frolicking through meadows together while eviscerating their enemies. 

Rage is a big boost to damage and a way to get damage reduction when you’re not Embiggening yourself. Reckless Attack is also excellent, especially if you’re comfortable damage racing with enemies, trying to kill them before they bring you down. 

That’s all good. Ancestral Protectors, the ability of the subclass, is better. Whenever you hit an enemy, they now suck at hitting everyone else. For a character that’s all about standing in the front, that’s a huge aid to doing what you wanna do. 

Soulknife Rogue: While it might not seem like a combination that makes sense, there’s a ton of synergy between these two classes. 

Firstly, nothing in the Rune Knight subclass prevents using light armor or weapons capable of sneak attack, and the passive abilities of many runes are explicitly keyed towards sneaking around. 

Second, the psychic blades of the Soulknife are a readily accessible weapon that’s always available, and can even be used to deliver Rune Invocations at range. 

What’s more terrifying than a character who sneaks into a room, then turns into a giant? Take a Halfling or Gnome for maximum hilarity. (Giant’s Might isn’t a size increase, it just turns you Large.) 

Would I recommend playing a Rune Knight Fighter?

The Rune Knight is an exceptional Fighter subclass. It combines two powerful abilities that scale appropriately at every level of the game and offers a whole lot of flexible strength. 

But more importantly, everything about the class is fun. The passives on offer let the character take on roles Fighters often don’t get to lean into, and all of the active abilities are impactful while offering some nice decision points. 

The Rune Knight does what’s probably the best thing a subclass can do. Builds on what’s already there, and makes it better. It takes a class that can be relatively linear and straightforward, then adds enough choice to be interesting, without threatening to drown new players. It’s a great subclass. Play it. 

Similar Posts

Leave a Reply

Your email address will not be published. Required fields are marked *