Rune Knight Fighter Subclass Guide

What Is a Rune Knight Fighter?

Fighters are master combatants, elite warriors who master martial forms practiced throughout the planes. These brave adventurers hold no innate abilities or magical powers, but they still train to be as mighty and as heroic as the wisest of clerics and the most knowledgeable of wizards.

As far as classes go, fighters really do set the standard for what it means to be a martial warrior. In many ways, the other martial classes are little more than variations on the fighter, tapping into and specializing in unique forms of martial prowess. 

The fighter subclass we’re looking at today verges on that territory. It doesn’t drastically shake up what it means to be a fighter at your core, but it certainly introduces a wealth of options that bring magic, strength, and power to a character beyond what a mundane warrior could access.

Today, we’re looking at the Rune Knight fighter, a subclass that enhances the natural strength and cunning of a fighter with the ancient practice of rune magic. Originating with the giants, runes are special symbols that hold deep supernatural powers, powers that a rune knight harnesses to empower their equipment.

We’ll be diving deep into what it means to be a rune knight, how to get the most out of this subclass, and how helpful runes really are to a fighter. Let’s get into it.  

Class-Defining Abilities

  • Runes
  • Giant Form
  • Double-down features

Runes

What is a Rune Knight fighter? They’re a fighter that uses runes, plain and simple. So, in order to really get to know what this subclass is good at, we have to talk about these runes and what they do.

Whenever a Rune Knight finishes a long rest, they can inscribe a number of runes (based on their level) onto different objects that are worn or carried (weapon, suit of armor, shield, jewelry, etc.). You must inscribe a different rune on each object, and an object can only hold a single rune at a time.

Some runes require creatures to make saving throws. In those cases, the save DC equals 8 + your proficiency bonus + your Constitution modifier.

There are only six total runes, so I’ll explain what each does and how beneficial each is. In general though, each rune has a passive effect and an activated ability. Additionally, you must finish a short or long rest before you can use the activated ability again.

Cloud Rune

This rune gives you advantage on Sleight of Hand (Dexterity) and Deception (Charisma) checks. Additionally, when you or a creature within 30 feet of you is hit by an attack roll, you can use your reaction to choose a different creature within 30 feet of you, other than the attacker, to receive the effects of the attack.

The cloud rune is definitely a very trickster-inspired rune. Passively it gives you great bonuses for social interactions since both sleight of hand and deception are skills you can choose to use at just about any time. 

The activated ability definitely makes this a powerful contender for the best rune though since you’re automatically transferring the effects of an attack to a new target without even having to worry about a saving throw. This can save you or an ally from death, be the perfect finishing touch on a strong enemy, or possibly even both.

Fire Rune

While wearing or holding this rune, your proficiency bonus is doubled for any ability checks you make with tools that you are proficient in. 

The activated ability provides a bonus effect when you hit a creature with a weapon attack. If you choose to invoke the rune, you deal an extra 2d6 fire damage to the target, and they must succeed a Strength saving throw or be restrained for 1 minute. While restrained, they take 2d6 fire damage at the start of each of their turns and can repeat the saving throw at the end of each of their turns, ending the effects on a success.

Evoking the spirit of the forge cleric or more fiery artificers, this is a great rune for combat that also opens up a lot of doors outside of combat. In fact, it could even be used to literally open doors if you have proficiency in thieves’ tools. 

Seriously though, to double your proficiency bonus with tools is an incredible bonus and can let you put some serious thought into which tool proficiencies you might want to pick up. At the very least, you’ll be getting smiths’ tools as a bonus proficiency from this subclass, and anything else is a bonus.

Then, dealing extra damage, potentially 32d6 of it, is absolutely incredible. Dishing out even just 2d6 of damage at lower levels is a big bonus, and this ability continues to be beneficial throughout a campaign.

If you do manage to restrain the creature with this, you’re not only dealing damage but preventing them from participating in the fight as well, a great way to deal with your biggest enemy. You’ll want to target a creature that doesn’t appear to have high strength, but even then, your constitution should be high enough to set a decently high DC for the save.

Frost Rune

Your passive ability gives you advantage on Animal Handling (Wisdom) and Intimidation (Charisma) checks.

The activated gives you a +2 bonus to all ability checks and saving throws that use Strength and Constitution. This effect is activated as a bonus action and lasts for a whopping 10 minutes. 

While Intimidation checks and a bonus to rolls are great, this ability does feel a bit lacking. This is mainly because the activated bonus won’t affect your attack rolls, which limits us to outside of combat or in combat and hoping that we end up making STR or CON saves.

Altogether, this is definitely beneficial, but it could certainly be improved if it wants to compete on the same level as the other runes we have access to.

Stone Rune

The stone rune gives its user advantage on Insight (wisdom) checks and darkvision out to a range of 120 feet.

When a creature ends its turn within 30 feet of you, you can use your reaction to force the creature to make a Wisdom saving throw. Unless the save succeeds, the creature is charmed by you for 1 minute. For the duration of the charm, the creature has a speed of 0 and is incapacitated. They can repeat the save at the end of each of their turns, ending the charm on a success.

The stone rune is really interesting and provides some serious variety of effects. Insight is great for social interaction, such a wide range of darkvision is great for exploration and combat, and the charm is obviously a huge boon in combat. Put these together, and you have probably the most well-rounded rune of the starting four. 

Hill Rune

In order to learn this rune, you must be level 7 or higher. 

The passive ability of this rune gives you advantage on saving throws against being poisoned and resistance to poison damage. The activated ability lets you use a bonus action to gain resistance to bludgeoning, slashing, and piercing damage for a minute.

For a rune with a level prerequisite, this is honestly a bit lackluster. Now, I need to be clear: These abilities are absolutely excellent; it’s just that they’re easily accessible. If you really want these abilities, you could choose dwarf as your race, since dwarven resilience gives you the same exact mechanical benefits as the passive ability. 

Then, and this is a bit harder to justify, you could get access to the activated ability and more by taking a single level dip into barbarian for their rage feature. Just doing that would give you those resistances twice a day along with bonus damage on attacks and a myriad of other benefits.

So, is this a good rune to choose? Yes, of course it is. These provide you some excellent resistances and ways to avoid taking some serious harm. Is it necessary? No, you could easily get all of the benefits of this rune at a much earlier level without having to choose it as one of your runes.

Storm Rune

In order to learn this rune, you must be level 7 or higher. 

This rune’s passive ability gives you advantage on Arcana (Intelligence) checks and prevents you from being surprised so long as you aren’t incapacitated.

The activated ability of the storm rune allows you to enter a 1-minute prophetic state through the use of a bonus action. For the duration, whenever you or another creature you can see within 60 feet of you makes an attack roll, saving throw, or ability check, you can use your reaction to cause the roll to have advantage or disadvantage. 

This rune is incredible. The only thing that could make it better is swapping out arcana for perception, but we’ll take it as it can still definitely be used as a handy skill check. The main benefit of the passive ability is definitely the surprise prevention, which kind of makes perception a nonissue as long as you don’t find yourself incapacitated.

Then, this really shines when you activate the prophetic state and start controlling the rolls of you and your allies like you were some sort of RNG god. There are just so many uses for advantage or disadvantage as this effect covers just about every roll you could make in the game aside from damage rolls and wild magic tables.

If you compare this to other roll-control abilities, this is probably one of the most powerful in the game. It certainly rivals the oft-lauded Portent ability of the divination wizard, and that lets you actually replace two of the same types of rolls each day. 

When you do the math, you’re affecting somewhere around 32 rolls in a day (given 16 rounds of combat and one short rest), and those can be just about anything you desire. Use this to stifle your enemies or bolster your allies. Either way, you’re making an incredible impact.

Okay, I know that was a lot, but hopefully, you’ve seen just how powerful these runes can be. I wanted to make sure those were front and center because, well, I get it — reading a big article like this can be a bit overwhelming at times. If you liked the insight though, keep reading because there really is a lot more to learn about this subclass.

Before we jump into the other abilities that really make this subclass what it is though, I just want to touch on one more thing about the runes. The number of runes you know is dependent on your level, and you can swap out a known rune at each level. By 15th level, you’ll know five runes altogether, which means there’s just one rune you won’t have access to, which will likely be either the frost rune or the hill rune (if you’re a dwarf and/or barbarian multiclass).

Giant Form 

You get access to runes at 3rd level, and with such a powerful ability, you’d think that’s it until your next subclass feature, but you’d be wrong. Third-level rune knights also gain Giant Might, a rage-like ability that you activate on a bonus action and lasts for 1 minute.

This ability makes you Large, along with anything you’re wearing, so long as your actual size is smaller than large to start with. You also gain advantage on Strength checks and saving throws and can deal an extra 1d6 damage with your weapon attacks or unarmed strikes once per turn. You can use this ability a number of times equal to your proficiency bonus, and you regain expended uses on a short or long rest.

This form is huge, get it? Seriously though, this feature is probably what saves this subclass from being mediocre. Since you can reliably activate this for almost every combat you enter, you can just about guarantee that you’ll be dealing extra damage on your attacks.

I’m not just talking about that wimpy d6 either. Since your equipment all becomes large as well, you’ll have a large weapon, which means doubling the dice you use when calculating damage. So for a Greataxe, that’s 2d10 instead of 1d10 and an extra 1d6 every turn. This is essentially doubling the amount of attacks you get in a turn.

Combat is obviously the main thing we want to focus on as a fighter, but the strength advantage and increased carrying capacity can have some impressive limitations when we’re exploring as well. Use this feature wisely, and you’ll feel not only like you are a giant but like you could easily fell one if push came to shove.

Double-Down Features

The best thing you can see in a feature is level scaling, when the feature improves steadily based on your level. The next best thing is what I like to call a “Double-Down Feature,” which is a feature you receive at later levels that improves something, or multiple somethings, from earlier features.

In other words, the rune knight is doing things right because from 10th level on, every feature you get is just meant to improve and build upon what you already have. 

You’ll steadily increase the additional giant’s might damage from 1d6 to 1d8, all the way to 1d10 of extra damage per turn. You’ll also gain the ability to invoke your runes’ activated abilities not once but twice before needing a short or long rest to recoup. 

Finally, and this is the really cool one, once you reach level 18 in this class, you’ll become Huge whenever you use your giant’s might feature, increasing your reach by 5 feet and tripling the damage you deal. 

Sure, you’ll only be as big as a hill giant, but you’ll certainly be much more agile as your size won’t diminish all the other great things you gain from being a fighter.

Altogether, this is an amazing class, and it’s rife for customization as the features it brings you offer a relatively wide range of benefits on and off the battlefield. 

Limitations

This is an excellent subclass, so keep in mind that I only keep this section around to remind you that all subclasses have their areas where they could be improved. 

The Rune Knight focuses on giving you supernatural abilities of giants. And yet, the only really giant-themed ability is the giant’s might feature you get at 3rd level. It’s certainly beneficial and so are the runic powers, but beneficial doesn’t mean synergistic.

When you take a step back and look at this class, it really starts to feel like a hodgepodge of leftover abilities with a very loose thread hanging them all together. Realistically, we have two different focuses here: giants and runes with the only connection being that giants are the original users of runes in the D&D mythos.

The giant portion of this subclass gives us strength and power beyond our wildest dreams. The runes, on the other hand, give us what is basically mock magic. 

In order for this to feel like a cogent and attractive subclass, we’d need to double down on something. 

I think the natural way to do this would be to increase the amount of runes we have access to, possibly even connecting the giant’s might ability to a specific rune. As of right now, we only have six runes (one for each type of giant), but there could certainly be more that aren’t one-for-one tie-ins with specific subspecies.

This also brings up the topic of customization. With a sum total of six runes and the ability to learn five of them, most Rune Knights are going to end up looking more or less exactly the same. At that point, just give us a simple progression of five, and call it a day.

Personally, I’d love to see a good list of 10 to 12 runes or possibly a progression that more echoes that of the totem warrior, allowing you to choose which runes to enhance at certain levels. 

The big problems we deal with in this subclass are not enough focus and not enough customization, which probably seems a bit ironic. When a subclass, or anything in D&D, tries to balance a wealth of options and a tight focus, it’s pretty much guaranteed that neither will be accomplished, and that’s what we see with the Rune Knight.

Fortunately, none of this makes the Rune Knight any less powerful. It might be a bit less fun to play, or rather, it might be a subclass you only want to play once, but that doesn’t change the fact that every ability you obtain is going to make a serious difference to your playstyle both on and off the battlefield. 

Would I like to see some really cool homebrew runes? Hell yeah, I would, and I’ve even made some on my own. At the end of the day though, that kind of only proves how much I actually like this subclass.

Black Citadel’s Ranking and Tier System

Color and Tier ranking are very helpful when you’re trying to digest a lot of information. In our ongoing series of 5e class guides, we use the following color-rating scheme:

  • RedC Tier. Red options can sometimes be situationally useful and might make for an interesting narrative choice, but they are largely less effective than other tiers.
  • GreenB Tier. Solid but nothing that is absolutely critical for a build, or Green can be very good but only in very specific situations.  
  • BlueA Tier. An excellent choice. Widely regarded as powerful in some way, useful, highly effective. 
  • PurpleS Tier. the top of our rankings. Objectively powerful or transformative in some way. No choice in D&D is essential, but these options are worth strongly considering when you create your character.

Our goal here is to provide scannable, but comprehensive guides for you as you develop your character.

While we might sometimes make reference to unofficial or homebrew content to illustrate a point (or just because it’s too cool not to talk about), every option we suggest is legal in the official rules for D&D 5e as published by Wizards of the Coast.

Ability Scores

When building a character, we start by figuring out which ability scores to focus on. For a Rune Knight, that’s going to be strength and constitution without a doubt. While most fighters can use strength or dexterity interchangeably, the focus on strength and size we see in this class just further locks us into melee strength-based combat.

Below I’ve listed each ability score and just how important it is to this subclass.

Primary: Strength 

Tier II: Constitution 

Tier III: Dexterity, Wisdom, Charisma

Dump Tier: Intelligence

Strength: The most important stat. This rules our ability and combat and also determines how much use we’ll get out of all the bonuses to strength checks and saving throws that we’ll get. With a bad strength score, even great bonuses can’t make much of a difference.

Dexterity: While we won’t be using this for much, it’s still incredibly important that we have a decent dexterity score so that our AC can justify us being on the front lines of battle.

Constitution: Not only does Constitution determine our hit points, but it also affects our runic save DC, something we’ll want to ensure is high if we want to have any chance of using them on our enemies.

Intelligence: We may want this if we choose to focus on arcana checks like our Storm Rune might suggest, but otherwise, we will almost never need this to be above 10.

Wisdom: Wisdom is useful for insight, perception, and more, and can be great for just generally discerning information. This is a solid competitor for our 4th-place score, although it might lose out to the next ability in some builds.

Charisma: There are two runes that give us advantage on a charisma-based skill, so if we want to reliably use deception or intimidation, this is the score to put points in so that we actually succeed on those checks. It should never go above Dexterity unless we want to multiclass, but in general, it’s a great contender for 4th place.

Race Choices

Next up, it’s time to decide a race for our character. This will affect our ability scores, and it will also give us a number of racial features that benefit us in a variety of ways. Each race offers up its own unique traits that give great starting improvements to us in combat, social interaction, or exploration.

Of course, 5e has had some big changes since it was first introduced in 2014, and we’ve seen the dawn of Custom Ability Score Increases as the new standard for races. While there are still plenty of races that offer up specific bonuses to one or two ability scores, many now give you the option to put +2 in one ability score and +1 in another or +3 in three separate ability scores.

Our recommendations are mostly based on the original type of 5e race since the Ability Score Increase is definitely the most important aspect to consider. If we suggest a newer race, that’s because the racial traits are outstandingly fitting for this subclass. 

Mountain Dwarf: +2 Strength and +2 Constitution is the perfect combo for this class and the best ability score increase you’ll find in any 5e race. Aside from that, we also get dwarven resilience, which offers the same poison-related benefits as the passive ability of the Hill Rune.

Goliath: +2 Strength and +1 Constitution is a close runner-up to the mountain dwarf. We also get Stone’s Endurance, a feature that lets us reduce incoming damage by 1d12 once before recharging the ability on a short or long rest.

Perhaps most important is the Powerful Build feature that says, “You count as one size larger when determining your carrying capacity and the weight you can push, drag, or lift.” This stacks with our giant’s might, so when we’re Large, we’ll count as Huge for carrying purposes, and when we’re Huge, we’ll count as Gargantuan! I’m sure you can come up with some incredible uses for this; all it takes is a small bit of creativity. 

Half-Orc: +2 Strength and +1 Constitution. Orcs are one of the few races that are going to give us some serious benefits in combat. Their Relentless Endurance is going to have us drop to 1 hit point instead of 0 if we wouldn’t die outright, a trait we can use once a day. 

More importantly though, Savage Attacks lets us roll one of our weapon’s damage dice an additional time when we score critical hits. With the amount of attacks available to fighters, this is going to stack up to a whole lot of additional damage over time.

Bugbear: Custom ASI. You’ll still want to use the same spread of Ability Score Increases as our other listed races, but you can switch it up if you want to. This race offers us the same Powerful Build trait as goliaths along with a collection of other helpful features. 

Long-Limbed increases our melee reach by 5 feet, which will stack with our final version of Giant’s Might for a total +10 ft of reach. Surprise attack lets us deal an extra 2d6 damage if we hit a creature that hasn’t moved yet in combat. This won’t trigger often, but it’s a nice chunk of damage to stack on. 

Skill Choices

Skills allow us to overcome obstacles outside of combat, whether those are puzzles, traps, or the scariest of all, social interaction. The skills we choose will often define how we roleplay our characters, so while I’ll be making suggestions, it’s important to choose the ones that interest you.

Fighters choose two skill proficiencies from Acrobatics, Animal Handling, Athletics, History, Insight, Intimidation, Perception, and Survival.

Acrobatics: This is a useful skill, but this subclass is much more focused on sturdiness than nimble movements.

Animal Handling: Animal handling is very campaign dependent. Some campaigns will hardly feature animals that can be handled, making this useless. Still, if you’re interested in taking it, you can always mention your interest to your DM in hopes that more opportunities to use it will arise.

Athletics: As the only strength-based skill, this is an important skill for us to choose if we really want to maintain our focus on strength checks. 

History: There isn’t much to suggest that this subclass would be knowledgeable about history, but again, take it if it suits you.

Insight: We can get advantage on insight checks through one of our runes, and it’s a very useful skill in social interaction.

Intimidation: Much like insight, we can get the most benefit from our intimidation rune if we already have proficiency in this skill.

Perception: Proficiency is always a useful skill as it’s one of the few that we use even passively. Adding proficiency here can protect us from surprise and give us the upper hand in many different scenarios.

Survival: Leave survival to the rangers and druids. 

Background Choices

Choosing a background is mostly about flavor. It gives us a foundation on which to build our backstory and also tells us how we make money and/or survive in the world. Additionally, backgrounds often offer us some starting equipment, proficiencies, and a feature or two that are all useful in the overworld.

The suggestions I have here are based more on archetypes than mechanical benefits. In truth, there really are no “optimized” backgrounds.

Gladiator: This background is for someone who wants to embody the fierce combatant spirit of a giant while keeping their character grounded in reality and simultaneously baking in a little bit of fun. 

Hermit/Archaeologist/Anthropologist: Any of these are great backgrounds if you want your character to have stumbled across and studied ancient giant runes to learn the secrets of the runic language. This gives a lot of credence to a character having sudden power and learning the ropes of a supernatural power source. 

Rune Knight Fighter Progression

Features that you automatically obtain through the Fighter class will appear in Yellow and features that you gain through the Rune Knight subclass will appear in Gray

Filling Out the Character Sheet (Level 0)

  • Hit Dice: 1d10 per Fighter level
  • Hit Points at 1st Level: 10 + your Constitution modifier
  • Hit Points at Higher Levels: 1d10 (or 6) + your Constitution modifier per fighter level after 1st

Proficiencies:

  • Armor: All armor, shields
  • Weapons: Simple weapons, martial weapons
  • Tools: None
  • Saving Throws: Strength, Constitution
  • Skills: Choose two skills from Acrobatics, Animal Handling, Athletics, History, Insight, Intimidation, Perception, and Survival

Equipment:

You start with the following equipment in addition to the equipment granted by your background:

  • (a) chain mail or (b) leather, longbow, and 20 arrows
  • (a) a martial weapon and a shield or (b) two martial weapons
  • (a) a light crossbow and 20 bolts or (b) two handaxes
  • (a) a dungeoneer’s pack or (b) an explorer’s pack

1st Level

Favored Enemy: 

Choose a fighting style from the list below:

  • Archery. Gain a +2 bonus to ranged weapon attack rolls.
  • Blind Fighting. You have blindsight with a range of 10 feet. 
  • Defense. Gain a +1 bonus to AC while wearing armor.
  • Dueling. When you are wielding a melee weapon in one hand and no other weapons, you gain a +2 bonus to damage rolls with that weapon.
  • Great Weapon Fighting. When you roll a 1 or 2 on a damage die for an attack you make with a melee weapon that you are wielding with two hands, you can reroll the die and must use the new roll, even if the new roll is a 1 or a 2. The weapon must have the two-handed or versatile property for you to gain this benefit.
  • Interception. When a creature you can see hits a target other than you within 5 feet of you with an attack, you can use your reaction to reduce the damage the target takes by 1d10 + your proficiency bonus. You must be wielding a shield or a simple or martial weapon to use this reaction.
  • Protection. When a creature you can see attacks a target other than you that is within 5 feet of you, you can use your reaction to impose disadvantage on the attack roll. You must be wielding a shield.
  • Superior Technique. You learn one maneuver of your choice from among those available to the Battle Master archetype. If a maneuver you use requires your target to make a saving throw to resist the maneuver’s effects, the saving throw DC equals 8 + your proficiency bonus + your Strength or Dexterity modifier (your choice). You gain one superiority die, which is a d6 (this die is added to any superiority dice you have from another source). This die is used to fuel your maneuvers. A superiority die is expended when you use it. You regain your expended superiority dice when you finish a short or long rest.
  • Thrown Weapon Fighting. You can draw a weapon that has the thrown property as part of the attack you make with the weapon. In addition, when you hit with a ranged attack using a thrown weapon, you gain a +2 bonus to the damage roll.
  • Two-Weapon Fighting. When you engage in two-weapon fighting, you can add your ability modifier to the damage of the second attack.
  • Unarmed Fighting. Your unarmed strikes can deal bludgeoning damage equal to 1d6 + your Strength modifier on a hit. If you aren’t wielding any weapons or a shield when you make the attack roll, the d6 becomes a d8. At the start of each of your turns, you can deal 1d4 bludgeoning damage to one creature grappled by you.

The best choices in this feature for a rune knight are probably great weapon fighting and superior technique. GWF will greatly increase your damage output while gaining a few battle maneuvers can bring a lot of diversity to this subclass’s abilities.

Second Wind:

On your turn, you can use a bonus action to regain hit points equal to 1d10 + your fighter level. You must finish a short or long rest before you can reuse this feature.

2nd Level

Action Surge:

On your turn, you can take one additional action. Once you use this feature, you must finish a short or long rest before you can use it again. Starting at 17th level, you can use it twice before a rest but only once per turn.

This feature is hugely beneficial and should definitely be used while you have one of your minute-long effects up and running so that you can get the maximum value.

3rd Level

Bonus Proficiencies: 

You gain proficiency with smith’s tools and learn how to speak, read, and write Giant.

Rune Carver: 

You learn two runes of your choice from among the runes available to this subclass. Each time you gain a level, you can replace a rune you know with a different one from this feature. At certain levels shown in the table below, you learn additional runes.

Whenever you finish a long rest, you can touch a number of objects equal to the number of runes you know and inscribe a different rune on each. The object must be something you can wear or hold in a hand. The rune remains until you finish a long rest, and an object can only have one rune at a time.

If a rune requires a saving throw, the DC is equal to 8 + your proficiency bonus + your Constitution modifier. 

Below is the list of runes available to you as written in Tasha’s Cauldron of Everything.

  • Cloud Rune. This rune emulates the deceptive magic used by some cloud giants. While wearing or carrying an object inscribed with this rune, you have advantage on Dexterity (Sleight of Hand) checks and Charisma (Deception) checks.
    • In addition, when you or a creature you can see within 30 feet of you is hit by an attack roll, you can use your reaction to invoke the rune and choose a different creature within 30 feet of you other than the attacker. The chosen creature becomes the target of the attack, using the same roll. This magic can transfer the attack’s effects regardless of the attack’s range. Once you invoke this rune, you can’t do so again until you finish a short or long rest.
  • Fire Rune. This rune’s magic channels the masterful craftsmanship of great smiths. While wearing or carrying an object inscribed with this rune, your proficiency bonus is doubled for any ability check you make that uses your proficiency with a tool.
    • In addition, when you hit a creature with an attack using a weapon, you can invoke the rune to summon fiery shackles: the target takes an extra 2d6 fire damage, and it must succeed on a Strength saving throw or be restrained for 1 minute. While restrained by the shackles, the target takes 2d6 fire damage at the start of each of its turns. The target can repeat the saving throw at the end of each of its turns, banishing the shackles on a success. Once you invoke this rune, you can’t do so again until you finish a short or long rest.
  • Frost Rune. This rune’s magic evokes the might of those who survive in the wintry wilderness, such as frost giants. While wearing or carrying an object inscribed with this rune, you have advantage on Wisdom (Animal Handling) checks and Charisma (Intimidation) checks.
    • In addition, you can invoke the rune as a bonus action to increase your sturdiness. For 10 minutes, you gain a +2 bonus to all ability checks and saving throws that use Strength or Constitution. Once you invoke this rune, you can’t do so again until you finish a short or long rest.
  • Stone Rune. This rune’s magic channels the judiciousness associated with stone giants. While wearing or carrying an object inscribed with this rune, you have advantage on Wisdom (Insight) checks, and you have darkvision out to a range of 120 feet.
    • In addition, when a creature you can see ends its turn within 30 feet of you, you can use your reaction to invoke the rune and force the creature to make a Wisdom saving throw. Unless the save succeeds, the creature is charmed by you for 1 minute. While charmed in this way, the creature has a speed of 0 and is incapacitated, descending into a dreamy stupor. The creature repeats the saving throw at the end of each of its turns, ending the effect on a success. Once you invoke this rune, you can’t do so again until you finish a short or long rest.
  • Hill Rune (7th Level or Higher). This rune’s magic bestows a resilience reminiscent of a hill giant. While wearing or carrying an object that bears this rune, you have advantage on saving throws against being poisoned, and you have resistance against poison damage.
    • In addition, you can invoke the rune as a bonus action, gaining resistance to bludgeoning, piercing, and slashing damage for 1 minute. Once you invoke this rune, you can’t do so again until you finish a short or long rest.
  • Storm Rune (7th Level or Higher). Using this rune, you can glimpse the future like a storm giant seer. While wearing or carrying an object inscribed with this rune, you have advantage on Intelligence (Arcana) checks, and you can’t be surprised as long as you aren’t incapacitated.
    • In addition, you can invoke the rune as a bonus action to enter a prophetic state for 1 minute or until you’re incapacitated. Until the state ends, when you or another creature you can see within 60 feet of you makes an attack roll, a saving throw, or an ability check, you can use your reaction to cause the roll to have advantage or disadvantage. Once you invoke this rune, you can’t do so again until you finish a short or long rest.

Giant’s Might: 

As a bonus action, you can imbue yourself with the might of giants, entering a form that lasts for 1 minute. During that time, you have the following effects:

  • If you are smaller than Large, you become Large along with anything you are wearing. If you lack the room to become Large, your size doesn’t change.
  • You have advantage on Strength checks and Strength saving throws.
  • Once on each of your turns, one of your attacks with a weapon or an unarmed strike can deal an extra 1d6 damage to a target on a hit.

You can use this feature a number of times equal to your proficiency bonus, and regain all uses on a long rest.

4th Level

ASI: 

You can either increase one ability by 2 points or two abilities by 1. Alternatively, you can choose a feature. If you already have great stats this is a great choice.

Martial Versatility (Optional):

Whenever you receive an ASI, you can also choose to do one of the following.

  • You can choose to switch out your fighting style for a different one. 
  • If you know any Battle Master maneuvers, you can replace one you know with a different maneuver.

5th Level

Extra Attack:

Fighters get to make a second attack whenever they take the Attack action as a part of their turn. This increases to three attacks at 11th level and four at 20th level.

6th Level

ASI

7th Level

Runic Shield:

When another creature you can see within 60 feet of you is hit by an attack roll, you can use your reaction to force the attacker to reroll the d20 and use the new roll. You can use this feature a number of times equal to your proficiency bonus, and you regain all expended uses when you finish a long rest.

This is an incredible ability that essentially functions like a soft version of the Storm Rune’s ability. Remember, you only get one reaction per round of combat, so you won’t be using this while your storm rune is activated. 

8th Level

ASI

9th Level

Indomitable:

You can reroll a saving throw that you fail. You must use the new role and can’t use it again until you finish a long rest. You can use this feature twice between long rests starting at 13th level and three times between long rests starting at 17th level.

10th Level

Great Stature: 

When you gain this feature roll 3d4, you grow a number of inches in height equal to the roll. Additionally, the extra damage you deal with your Giant’s Might increases to 1d8.

The height is basically a nonissue, but it’s a nice bit of flavor. Technically, this could put some creatures into the next size category though, so make sure you know your height going into this build. 

The real draw is obviously the extra damage, and trust me, bumping up to 1d8 from 1d6 is going to make a difference.

12th Level

ASI

15th Level

Master of Runes: 

You can now invoke the activated abilities of each of your runes twice rather than once before you need to replenish on a short or long rest.

16th Level

ASI

18th Level

Runic Juggernaut: 

The extra damage you deal with the Giant’s Might feature increases to 1d10. Additionally, when you use that feature, your size can increase to Huge, and while you are that size, your reach increases by 5 feet.

19th Level

ASI

Feat Options

Feats are an excellent way to customize, specialize, and optimize your build. You can use them to pick up the slack in areas where your build is lacking, or you can use them to bolster the abilities that are already powerful. 

Fighters get access to one more ASI than all the other classes, meaning they can get one more feat than other classes.

Below are a few suggested feats that fit perfectly with the Rune Knight.

Polearm Master: This feat is the perfect choice for characters using one of three reach weapons (glaive, halberd, or quarterstaff). It allows you to make a bonus action attack with the non-business end for a d4 of bludgeoning damage. More importantly though, this feat allows you to make opportunity attacks whenever a creature enters your reach.

This is a great feat normally, creating a 10-foot radius around you that creatures won’t want to pass through. With your giant’s might adding an extra 5 feet, that’s a 15-foot radius. If you take bugbear, that’s an incredible 20-foot radius that you can make opportunity attacks within.

Sentinel: The perfect feat to pair with polearm master, this feat reduces a creature’s speed to 0 when you hit them with an opportunity attack, allowing you to keep them in your clutches. You can also make opportunity attacks within 5 feet even if the creature takes the Disengage action, and you can use your reaction to attack a creature that makes an attack against a target other than you.

The only thing that could make this pairing better would be some way to get more reactions in a single turn. 

(If you want to try your hand at some old UA material, the Tunnel Fighter fighting style does just this, allowing you to enter a defensive stance as a bonus action on your turn so that opportunity attacks don’t require a bonus action.)

Great Weapon Master: Another feat that can stack with the polearm master combo but is equally good on its own is the great weapon master. This feat lets you make an additional melee weapon attack as a bonus action whenever you reduce a creature to 0 hit points or score a critical hit. 

Additionally, when you make a melee weapon attack with a heavy weapon, you can take a -5 penalty to the roll in exchange for a +10 bonus to damage on a hit. This is well worth the risk, especially with a good strength score aiding you. 

Rune Knight Fighter Build 

For the following example build, we’ve used the standard set of scores provided in the PHB (15, 14, 13, 12, 10, 8) when deciding ability scores. 

This section will provide you with a collection of the best choices from this article put into a single character build along with explanations of different synergies and a general path for progression. 

  • Race: Bugbear
  • Background: Far Traveler
  • Ability Scores: STR 16,  DEX 13, CON 16, INT 8, WIS 10, CHA 12
  • Skill Proficiencies: Insight, Intimidation, History, Survival
  • Language Proficiencies: Giant, Goblin, Common
  • Tool Proficiencies: Smith’s Tools, Cartographer’s Tools
  • Equipment: Chain mail, glaive, great axe, two handaxes, explorer’s pack, wooden case containing a map to a ruin or dungeon, a bullseye lantern, a miner’s pick, a set of traveler’s clothes, a shovel, a two-person tent, a trinket recovered from a dig site, and a pouch containing 25 gp
  • Fighting Style: Great Weapon Fighting
  • Feats: Great Weapon Master (4th), Sentinel (8th), Polearm Master (10th)

Runes:

  • 3rd Level: Cloud Rune, Fire Rune
  • 7th Level: Storm Rune
  • 10th Level: Hill Rune
  • 15th Level: Stone Rune

This build focuses on making us large and in charge, of the battlefield that is. We’re all about battlefield control, and focusing on reach weapons is an excellent way to do that, especially as we grow in size. 

We start off pretty straightforward, focusing simply on dealing as much damage as we can with our heavy weapons. Getting the nice synergy between great weapon master and great weapon fighting, we’re guaranteed to dish out some serious damage even before we consider other abilities.

We then strive to pick up the sentinel and polearm master combo by the time we reach 10th level, and our giant’s might extra damage increases to 1d8. At this point, we’re completely in control of the battlefield, and coming near us is a death sentence for most enemies.

As far as runes are concerned, we pick up the best basic ones, allowing us to deal extra damage and protect our allies. Then, as soon as we can, we’re picking up Storm Rune so that we can quite literally control the rolls of others; well, at least we can hope they roll differently the second time.

The final build is a character with a 20-foot reach and a wide range of opportunity attacks that can dish out a load of damage on a single attack if all abilities stack nicely. On the rare occasions where that isn’t enough, we have charming abilities and more mystical battlefield control to cover our bases.

The Rune Knight is a powerful combatant and is rife with opportunity for players looking to engage in some really interesting roleplay. There’s also a good deal of room to mess around with some homebrew if you’re interested in that kind of thing, so there’s really something here for everyone.

I hope this article has given you everything you need, and as always, happy adventuring.