Bladesinger Wizard Subclass Guide: The Dancing Blades

Last Updated on January 22, 2023

Bladesinger Wizard

To some, a weapon is a crude instrument of destruction, a means to an end. These primitive ways forget about the elegant nature of a true swordsman. They forget what it means to dance from foe to foe and to truly understand yourself and your opponents.

There is an ancient tradition far more graceful than the savage sellswords who roam the lands. Perfected long ago by elven warriors, the art of the bladesong is as much a practice of magic as it is a practice of true swordsmanship. 

It has been passed down through the ages, and while it is no longer practiced exclusively by the fair folk, it has lost none of its grace or might. Do you have what it takes to become a true bladesinger?

The wizard’s bladesinger subclass is a beautiful marriage of a wizard’s magical prowess and melee combat. If you can’t decide between a melee class and a caster, this is one of the most exciting options by far, particularly because it is by no means a half-caster.

Enjoy full access to the wizard’s spellcasting prowess while slicing and dicing your way to victory. Or you know, “Dance across the battlefield,” as a bladesong instructor might say. 

In this article, we’re going to be diving deep into this subclass and looking at all the ways it excels, any shortcomings it might have, and how to build the best bladesinger for your next 5e campaign.

Class-Defining Abilities

• Melee Combat
• Rage-like Bonuses in Combat
• Spells as Support

The bladesinger is made possible by the proficiencies it allows a wizard to gain — those being light armor and a single one-handed melee weapon. They set you up as a wizard who can actually fight and hold their own and then continue to provide you abilities that show that.

I would say the place that this subclass excels the most is in how it sets up a bladesinger character. A bladesinger is not a martial expert who can cast some spells; a bladesinger is a powerful wizard with expertise in martial combat. That distinction keeps this subclass of wizard separate from every different half-caster and ⅔ caster out there.

Being able to participate in melee combat is clearly the most helpful “feature” of this subclass. 

We need these proficiencies in order to perform, and it gives us a chance to really excel, but it’s just a chance. Without other abilities to support us, we would only ever be as strong as a low-level fighter. Thank God, we do have other features improving our ability to fight.

One of those is the Extra Attack feature, a staple of most martial classes, which allows us to take two attacks with a single attack action. And, to make things a bit more exciting, we can swap one of those attacks for a cantrip.

This means we can set up with Booming Blade or Green-Flame Blade, and then immediately follow through with another melee attack. There are other options of course, and we’ll get into those later, but we get a really nice clear plan of attack built in once we pick up this 6th-level feature.

That little line about cantrips also highlights the main functionality of this subclass. We can use our spells to enhance our relatively minor melee abilities. Instead of a litany of features making us a more competent fighter, we can simply boost any melee attack we might make with something exciting and hand picked for the moment.

Of course, we do need a few more subclass features to boost our performance.

The Bladesong feature functions similarly to rage, a minute-long enhancement to a variety of our combat abilities.

This feature, activated on a bonus action, can be used so long as we aren’t wearing medium or heavy armor and we’re not using a shield. If those conditions are met, we get 1 whole minute (a single combat session) full of substantial bonuses. Here are the main benefits of the bladesong:

• Bonus to AC equal to INT modifier
• Walking speed increased by 10 feet
• Advantage on acrobatics checks
• Bonus to concentration saves equal to INT modifier

This really melds components from various martial traditions together. Agility, speed, and focus are the key tenets of the bladesong, and they carry through well. 

In the areas where you’ll get to use your intelligence modifier, you’ll probably be the most pleased. That’s a substantial bonus to be throwing at things typically difficult for a wizard to rely on. Then, we have a huge bonus to speed, one that we don’t need to expend any actions to gain. If we do burn a dash action though, we’ll be flying across the battlefield at around 80 ft. per round.

The only one I’m hesitant about is acrobatics. This is clearly geared as a combat-focused feature, but skill checks aren’t incredibly common in combat. Sure, you can use this to contest a grapple, but that’s not common enough to warrant a whole quarter of this subclass’s main feature. 

Rather, I think this is here to encourage creativity from the players and DMs at any table where a bladesinger is present. Perhaps some parkour might allow them to get behind an opponent, or they might be able to slide underneath the feet of an enemy. The mechanical advantages will be up to the DM, but that’s the way we like it — it allows us to work outside of the (sometimes) narrow 5e mindset.

With all that this subclass has going for it, spells are really used as a way to support the main abilities rather than the other way around like most wizards.

This style isn’t objectively better or anything, but it certainly means that a bladesinger won’t get in as many pinches as your average wizard might. While wizards are the most competent spellcasters, they can still end up in a scenario where they’ve burned the wrong slot and can’t rely on the solution they had prepared.

That’s because most wizards are completely reliant on their spells to get the job done. In comes the bladesinger, a wizard who can get along quite fine without burning a single spell slot. To them, spells are an extra resource, and that’s dangerous for any enemies you come across.

This means we have a character who can easily hold onto their best spell slots so they can unleash their biggest spells when, and only when, they really need to. 

Limitations

• M.A.D. Build
• Linear Spell Selection

A big issue with this subclass is its tendency toward creating a M.A.D. (multi-ability dependent) character. 

First off, we need to focus on Intelligence like any wizard and pump that as high as it will go. Then, especially since we’ll actually be up in the fray, we’ll need to improve our Constitution for high hit points and good concentration saves. 

Lastly, this subclass calls for good Dexterity. Its entire focus is on us being nimble; plus we’ll be using it to get a good AC with light armor and, more than likely, as our weapon’s attack modifier. 

Each of these abilities is just as important as the last. Okay, maybe that’s a bit extreme. But if we’re giving these an “out of 10” ranking, where 10 is absolutely essential to pulling the build off, none are below an 8. 

Normally, we like to clearly see first, second, and maybe third place when we’re dealing with ability score importance. That lets us work with something like a 17, 14, 14 and be completely fine (the three highest scores of a standard point array with +2 and +1 racial modifiers applied appropriately).

These scores are barely passable for a bladesinger who wants to excel, which means a few things. We have to either (a.) get the perfect feats to elevate our build or (b.) focus all of our ASIs into score improvement. Until we can get a minimum of +3 bonus in each of our important scores, we’re really just scraping by.

Unfortunately, this isn’t where our worries end. A subclass like this can gain a lot from multiclassing, but that can be difficult when we’re already spread thin on our ability scores and ASIs.

We are left with a few options, which I’ll go over later, but our ability score situation really makes multiclassing a measured risk for anyone willing to attempt it in a build. 

Beyond that is something that is less of a problem and more of a true limitation: our stock of spells.

I call it a linear spell selection because that’s what it is, mostly. Your typical wizard can choose just about any spells that they would like to. Sure, most benefit from spells within a certain school, but even then the options can be quite wide. 

A bladesinger, however, would be wise to pick up spells that matter when combat starts and you run into battle with nothing but a rapier and some leather armor. Specifically, you want the kind of spells that you would normally be using to buff up your more martially trained allies.

There’s enough that you do have some options, but realistically, most bladesingers will have the same basic “loadout” of spells. 

Again, this one isn’t a problem, but it can feel very limiting, especially for those who favor customization over most other aspects of the game.

Race Choices

You can’t have a character without a race, and choosing one is probably one of the most exciting processes when it comes to building a character. You have to make a lot of decisions when picking the right race for your character, but interestingly, those choices have changed in the past few years.

Since 5e came out, one of the most important parts of choosing your race has been picking the Ability Score bonuses that fit best with the class you choose. A typical race has had set Ability Score bonuses (such as +2 Intelligence and +1 Dexterity) along with some unique racial traits. 

In recent years, that’s started to change as more and more races have come out that allow you to choose custom ability scores. New races like the Faery and revised races like the Goliath can be used for just about any character if you like their features and style.

In this section, our recommendations are still based on the way races have worked in 5e for the last decade, but talk to your DM about how custom lineages work at their table. If custom ability scores are allowed for any or even a few races, feel free to ignore this bit of advice and choose a race that you think is cool.

Rock Gnome – INT +2, CON +1. Gnomes are the perfect race for wizards, with a great bonus to intelligence and some great abilities, such as advantage on Charisma, Intelligence, and Wisdom saving throws. This will be a good build that is protected from other spellcasters while definitely receiving the bonuses we want. 

Note: Other gnomes work as well. Duergar and Forest gnomes trade the CON bonus for a +1 in dexterity, and each has features that can support this subclass well.

High Elf – DEX +2, INT +1. The race that this subclass was made for… literally. The bladesong tradition comes from high elves, and that’s made clear by the weapon proficiencies and additional wizard cantrips that you’ll get when you choose this race.

Beyond this, you’ll have to look for some custom ability score races, since Intelligence is absolutely necessary for this build. Hypothetically, you could go with a build that offers bonuses to Constitution and Dexterity, but only if you lucked out with an incredible roll (17 or 18) that you can put into Intelligence.

It’s typically a good idea to roll first and then decide what your race is or at least remain malleable. If we’re not using custom ability scores, we really need to choose the race that covers our bases on bad rolls. 

Skill Choices

We tend to choose these based on our highest stats, but choosing a different route based on how you want to roleplay isn’t a bad idea, especially since adding your proficiency bonus might compensate for a not-so-good ability modifier.

The wizard class is given the ability to choose two skills from Arcana, History, Insight, Investigation, Medicine, and Religion.

• Arcana (INT) – You can use this to investigate magical items or simply learn more about the magical nature of something important.
• History (INT) – Similar to arcana, history checks will let you glean information about your surroundings. This is definitely helpful but not something you need to rely on.
• Insight (WIS) – Understanding someone’s intentions is helpful, especially for a warrior of a proud, honorable tradition.
• Investigation (INT) – You could use spells to seek things out, but this will save your slots for more important things.
• Medicine (WIS) – You don’t need this skill at all. Medicine doesn’t really come into play with the theme, and you can just let a cleric or druid worry about the medicinal side of things.
• Religion (INT) – I would avoid religion unless it’s important to your character’s backstory. 

Background Choices

When we look for a background, we want to find some skills that synergize well with our ability scores, but that’s not all. We also want the basis for a character who would have reason to study the tradition of bladesong. This could come from our elven heritage, or it could be based in the line of work we’ve found ourselves in.

Whatever the reason we choose our backgrounds, they are an important part of a character and shouldn’t be easily overlooked. This is the grounds for your backstory and by that right, the basis of the entire personality of your character.

Noble – Proficiency in History and Persuasion. 

Mechanically, this background offers you either a position of privilege, which sees the common folk doing what they can to appease and comfort you, or retainers, commoners who will perform mundane tasks for you.

Storywise, though, is where this gets exciting. There are a few ways to spin it, with the obvious being a noble elf trained in the ancient arts, but that lacks a bit of inspiration in my opinion. Personally, I’m more a fan of the Arya Stark route.

Your character could be a noble who was trained by some foreign dignitary in the ways of the bladesong, giving them an excellent reason to practice a fighting style so uncommon in whatever area of the world you find yourself.

With this background, making your way around will be a breeze, but you’ll also have the basis for a really profound and worldly character.

Far Traveler – Proficiency in Insight and Perception. 

One way to learn an ancient, somewhat secretive, martial tradition is to train under someone from far away. Another is to simply be someone from far away. With this choice, you get a character who is mysterious and exciting all at the same time.

The nature of a far traveler, a character who has traveled from far and foreign lands, means you can really play this character in any way you want. You can also graft any other background you’re interested in on top of this and still maintain the intrigue. 

Want to be a knight? You’re a knight from a distant land. Guild artisan? Distant land. You get the picture.

Bladesinger Wizard Progression

Features that you automatically obtain through the Wizard class will appear in Yellow, and features that you gain through the Bladesinger subclass will appear in Gray. 

Filling Out the Character Sheet (Level 0)

• Hit Dice: 1d6 per Wizard level
• Hit Points at 1st Level: 6 + your Constitution modifier
• Hit Points at Higher Levels: 1d6 (or 4) + your Constitution modifier per wizard level after 1st
• Proficiencies
• Armor: None
• Weapons: Daggers, darts, slings, quarterstaffs, light crossbows
• Tools: None
• Saving Throws: Intelligence, Wisdom
• Skills: Choose two from Arcana, History, Insight, Investigation, Medicine, and Religion
• Equipment: You start with the following equipment, in addition to the equipment granted by your background:

• (a) a quarterstaff or (b) a dagger
• (a) a component pouch or (b) an arcane focus
• (a) a scholar’s pack or (b) an explorer’s pack
• A spellbook

1st Level

Spellcasting: 

Spellcasting is the main source of a wizard’s power. Wizards use Intelligence as their spellcasting ability, so your Spell Save DC is 8 + your proficiency bonus + your Intelligence modifier, and your Spell Attack modifier is your proficiency bonus + your Intelligence modifier.

Wizards use a spellbook, which starts off with six 1st-level spells. As you find or learn other spells, you can copy them into your book.

Each day you can prepare a number of spells, chosen from your spellbook, equal to your Intelligence modifier + your wizard level. 

You know a number of wizard cantrips, which you can cast at will as shown on the table above.

Arcane Recovery: 

On a short rest, you can recover spell slots. The levels of the slots you recover can combine to a total of half your wizard level. For example, if you are a 4th-level wizard, you can recover one 2nd-level spell slot or two 1st-level spell slots on your short rest.

This is always going to be useful, and you’ll quickly decide which spell slots are the most valuable for you to get back.

2nd Level

Training in War and Song:

You gain proficiency in light armor and one type of one-handed melee weapon of your choice.

Your best bet here will be the rapier since it is a finesse weapon and you can use dexterity as your attack modifier. As for light armor, get what you can afford as soon as you can.

Bladesong:

If you are not wearing medium or heavy armor or carrying a shield, you can activate the bladesong as a bonus action. For a minute, you have the following bonuses:

• You gain a bonus to your AC equal to your Intelligence modifier (minimum of +1)
• Your walking speed increases by 10 feet.
• You have advantage on Dexterity (Acrobatics) checks.
• You gain a bonus to any Constitution saving throw you make to maintain your concentration on a spell. The bonus equals your Intelligence modifier (minimum of +1).

The bladesong ends early if you are incapacitated; if you make a two-handed weapon attack; if you don medium armor, heavy armor, or a shield; or if you dismiss it as a free action.

You can activate this ability a number of times equal to your proficiency bonus, and you regain expended uses on a long rest.

3rd Level

Cantrip Formulas (Optional):

Whenever you finish a long rest, you can replace one of your known wizard cantrips with another wizard cantrip. This is a great optional feature introduced in TCoE that really allows you to explore all of your options.

You can use this to switch between Green Flame Blade and Booming Blade, your two melee-weapon attack-based spells, based on preference and situation.

4th Level

ASI: 

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

As I’ve said before, we want to focus on getting our main modifiers up to at least +3. This means a score of 16 in Intelligence, Constitution, and Dexterity. It’s important to plan out ASIs as you build your character. That way you can know how many you need to take and how many you can substitute for feats. 

Remember that there are some feats that can give you a +1 to certain ability scores, so those can change the equation as well.

6th Level

Extra Attack:

You can make two attacks in an Attack action instead of one. Additionally, you may replace one of those attacks with a cantrip. 

This will, no doubt, serve you extremely well, especially since the main cantrips we’ll be focusing on are basically melee attacks with a bit of added flourish.

8th Level

ASI

10th Level

Song of Defense:

When you take damage, you can use your reaction to expend one spell slot and reduce that damage to you by an amount equal to five times the spell slot’s level.

At 10th level, this means a maximum reduction of 25, which is nothing to shake a stick at. Compare that to the average wizard’s HP at this level, 60, and you can see how much of an impact this really has. 

If you can afford to save even one of each spell slot below 5th for this feature, you’ll be saving yourself from 50 damage every day. You basically have multiple lives worth of protection baked into this feature, but remember that the less you have to use it, the better.

12th Level

ASI

14th Level

Song of Victory:

You can add your Intelligence modifier (minimum of +1) to the damage of your melee-weapon attacks while your Bladesong is active.

Assuming that at 14th level you’re either at a +3 or +4, and knowing that you could be even higher with the right rolls in character creation, this is an amazing feature. You’ll be boosting your average damage output in combat by at least around 80. Don’t believe me?

If you succeed on 60% of your attacks and attack each turn in a 16-round combat, that’s about 22 successful hits (remember that you have extra attack). What’s 22 x 4? Yeah, you get to dish out some serious damage, even if adding your modifier seems small in the short term.

This is your capstone ability, and if you make it to this, congratulations, you’re a true bladesinger. Now the only thing left to do is pick up another feat and get stronger, and maybe find some good magical weapons.

16th Level

ASI

18th Level

Spell Mastery:

Choose a 1st-level wizard spell and a 2nd-level wizard spell that are in your spellbook. You can cast those spells at their lowest level without expending a spell slot when you have them prepared. If you want to cast either spell at a higher level, you must expend a spell slot as normal.

By spending 8 hours in study, you can exchange one or both of the spells you chose for different spells of the same levels. 

19th Level

ASI

20th Level

Signature Spell: 

When you reach 20th level, you gain mastery over two powerful spells and can cast them with little effort. Choose two 3rd-level wizard spells in your spellbook as your signature spells. You always have these spells prepared, they don’t count against the number of spells you have prepared, and you can cast each of them once at 3rd level without expending a spell slot. When you do so, you can’t do so again until you finish a short or long rest.

If you want to cast either spell at a higher level, you must expend a spell slot as normal.

For this, here are my top suggestions:

• Ashardalon’s Stride – One-minute concentration spell that increases your movement speed by 20 feet, protects you from opportunity attacks, and deals 1d6 fire damage to creatures that you move within 5 feet of. A perfect bonus to an already swift combatant.
• Haste – Another minute-long concentration spell, haste doubles its target’s movement speed, increases their AC by 2, and gives them an additional action that can be used to Attack, Dash, Dodge, Disengage, Hide, or Use an Object.

The one backlash is that the target, which will probably you, can’t move or take actions the turn after this ends. Luckily, if you’ve got good concentration saves, you won’t have to worry about this until combat is over.

• Spirit Shroud – One-minute concentration spell. Are you seeing a pattern? For the duration, any attacks you make against a creature within 10 feet of you deal an extra 1d8 damage that is either cold, radiant, or necrotic, your choice. Creatures that take this damage can’t regain hit points until the start of your next turn, meaning you can continuously drop them without any opportunity for them to heal.

Additionally, any creatures of your choice that start their turn within 10 feet of you have their movement speed reduced by 10 feet.

Altogether, this is an insanely beneficial spell for a bladesinger looking to dish out a whole lot of damage.

These spells all bring something to the table that can feel like an addition to your bladesong, a customization if you will, allowing you to truly sing your own song of battle. 

Plus, since these are concentration spells, their bonuses aren’t just one-and-done like a typical spell. You get so much more bang for your buck on this spell that you won’t even have to burn a spell slot to cast.

Feat Options

Feats are a great way to improve our characters by either leaning into our strengths or covering our weaknesses. They do come at a cost though, especially for our bladesinger. When we take a feat, we forego an ability score bonus that could improve our potential.

Since wizards have 5 ASIs altogether, it stands to reason that we’ll split these 3 and 2, depending on where we need the most help. Below are a handful of feats that can be helpful to this subclass.

Mobile – This feat increases your speed by 10 feet and protects you from opportunity attacks made by creatures that you’ve attacked. Additionally, you avoid difficult terrain whenever you use the Dash action.

This is excellent for the bladesinger who wants to lean further into their agile ways. Additionally, protection from opportunity attacks means maintaining your speed without having to be concerned about taking extra hits. Perfect for the in-and-out attacker.

Durable – For starters, this boosts your constitution score by 1, meaning you’re only half skipping an ASI. 

The ability part of this feature is that the minimum amount of hit points you can receive when you roll to heal on hit dice is equal to double your constitution modifier. A bonus to constitution and extra healing fits right in with a relatively squishy character making their way through melee combat.

Tough – If you’re lacking on hit points, this is the feat for you. It gives you an increase to your hit point maximum equal to twice your level when you gain this feat, and then you gain an additional two points whenever you level up.

You could easily rephrase this as “you receive a standing bonus to your hit point maximum equal to twice your level,” but I wanted to keep the language of the PHB.

War Caster – This feat is borderline necessary, giving you everything you need to excel in combat as a caster/martial combo. 

• Advantage on concentration saves.
• The ability to use somatic components even with your hands full of weapons.
• You can cast a spell instead of making a melee attack when you are presented with an opportunity attack.

This is an insanely beneficial feat, and I would take it on the concentration save advantage alone, but each benefit is perfectly tailored to this subclass. 

Fighting Initiate – If there’s anyone who knows fighting, it’s fighters. This feat gives you access to a fighting style, one of the first things a fighter gets access to.

Defense, which gives you a boost to AC, or dueling, which increases your damage rolls if you’re only using a one-handed weapon, are the best options here. Of course, you can get exciting and take superior maneuvers to get access to any of the wonderful tactics available to the battle master.

Piercer – Lastly, piercer (and any of the damage-based feats) work well if you just want to excel at the weapon you’re using. It will give you a +1 to your Dexterity along with the ability to reroll your piercing damage and deal extra critical-hit damage.

Bladesinger Wizard Builds

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. The only levels mentioned for the purpose of these builds are those when you will have the opportunity to make a decision on how your adventurer grows.

• Race: High Elf
• Background: Noble
• Ability Scores: STR 8,  DEX 15, CON 14, INT 16, WIS 12, CHA 10
• Skill Proficiencies: Arcana, Insight, History, Persuasion
• Language Proficiencies: Elven, Common, Draconic
• Tool Proficiencies: Chess
• Equipment: Dagger, arcane focus, explorer’s pack, spellbooka set of fine clothes, a signet ring, a scroll of pedigree, and a purse containing 25 gp.

1st Level

Spellcasting:

You gain access to cantrips. Here are a few good choices:

• Blade Ward – Resistance to bludgeoning, piercing, and slashing damage until the start of your next turn.
• Booming Blade – A melee attack that deals extra damage if the target willingly moves before the start of your next turn.
• Green Flame Blade – A melee attack that deals fire damage to a creature within 5 feet of the target of your attack. At higher levels, this deals fire damage to the target of your attack and an additional target.
• Sword Burst – A useful sword-themed AOE spell that sends blades hovering around you, dealing damage to all other creatures within 6 feet of you.
• True Strike – A concentration spell that grants you advantage on the next attack you make against your target.

You gain access to 1st-level spell slots. Good spells of this level to prepare are as follows:

• Absorb Elements – A reaction spell that reduces incoming elemental damage and adds it to the next melee attack you make.
• Longstrider – Increases a target’s speed by 10 feet for 1 hour. Obviously, this works excellently on you, but you can support your allies with this if need be.
• Shield – A reaction spell that creates a barrier of force to give you a +5 bonus to AC. Excellent candidate for Spell Mastery later on.

3rd Level

Spellcasting:

You gain access to 2nd-level spell slots. Good spells of this level to prepare are as follows:

• Kinetic Jaunt – Increase your movement speed by 10 feet, avoid opportunity attacks, and gain the ability to move through the space of another creature.
• Magic Weapon – Turn a mundane weapon into a magical one that has a +1 bonus to attack and damage rolls.
• Misty Step – As a bonus action, teleport up to 30 feet to an unoccupied space you can see. Great for quick traversal if you need to get around a group of enemies.
• Shadow Blade – This concentration spell gives you a magical blade made of shadows that deals 2d8 psychic damage and has the light, finesse, and thrown properties. In addition, when you make attacks with this in dim light or darkness, you do so with advantage.

This is an excellent spell to pair with your bladesong, making it more unique and far more powerful.

4th Level

ASI: War Caster

5th Level

Spellcasting:

You gain access to 3rd-level spell slots. Good spells of this level to prepare are as follows:

• Ashardalon’s Stride, Haste, Spirit Shroud – I’ve gone over each of these in the Signature Spells 20th-level feature of the progression guide above.

7th Level

Spellcasting:

You gain access to 4th-level spell slots. Fire Shield is a great spell to prepare for this level. Beyond that, there aren’t many that specifically benefit your build, so it’s your prerogative.

• Fire Shield – A shield that protects you from either fire or cold damage (via resistance) and that rebukes those who hit you with melee attacks by dealing the inverse damage type of your choice.

8th Level

ASI: +1 Dexterity, +1 Constitution

9th Level

Spellcasting:

You gain access to 5th-level spell slots. There aren’t any spells that scream bladesinger, but you can use these slots to upcast your earlier spells, and then just choose a few situational ones from this level’s selection.

11th Level

Spellcasting:

You gain access to 6th-level spell slots. 

12th Level

ASI: Durable Feat

13th Level

Spellcasting:

You gain access to 7th-level spell slots. 

15th Level

Spellcasting:

You gain access to 8th-level spell slots. 

16th Level

ASI: Mobile or +2 Intelligence

17th Level

Spellcasting:

You gain access to 9th-level spell slots. 

19th Level

ASI: +2 Intelligence or +2 Dexterity

Multiclassing

While this is a character who teeters on the edge of M.A.D., you can still get away with multiclassing if you choose well and don’t overextend yourself. To do so, you’ll want to choose a class that utilizes either Intelligence or Dexterity and that can give you benefits without you needing to take more than a three-level dip.

Of the available classes, the two that stand out are rogue and artificer. Each can give you additional martial prowess, where one focuses on your Intelligence and the other calls on your Dexterity.

Battle Smith Artificer 

Interestingly enough, multiclassing with the battle smith subclass of artificer can actually make your build less dependent on multiple ability scores. This is because at 3rd level, battle smiths gain the ability to use Intelligence instead of Dexterity or Strength as their weapon modifiers. 

Of course, this comes with other bonuses, such as artificer infusions and a steel defender to serve as your faithful ally. You also don’t sacrifice much of your spells since multi-classed casters calculate their slots differently and the artificer is essentially a combat wizard already.

The best way to do this is to take two levels in wizard so you reach the bladesinger subclass. Then, spend the next three levels learning the way of the artificer. After that, if you want your build to be more than a 17/3 split between wizard and artificer respectively, you definitely can without sacrificing much progress in either direction.

Rogue

You can take a single level of rogue to gain access to sneak-attack damage, but if you go further, you will be rewarded with a bit more damage and some more exciting features.

There are actually several fitting subclasses if you want to make a three or more level dip into this stealthy class. 

The soulknife will give you automatic access to an impressive magical weapon and some extra psionic-based powers that will complement your agile character well.

The arcane trickster will allow you to take more levels in rogue while still increasing your spell slots and spell list. Excellent if you’re only multiclassing to find a bit more damage.

Either of these subclasses will do well for you and allow for the multiclassing to be more than just a dip. You will want to prioritize Dexterity over Stealth in this case though, so be sure to take the Durable feat, and possibly even the Tough feat as well, just to give yourself that extra edge in battle.

Closing Thoughts

The bladesinger is an ambitious character. It takes the squishiest class in all of 5e and puts a sword in their hand. Luckily, it gives them more than just a sword, and their agility, coupled with their magical prowess, allows them to be truly devastating on the battlefield.

This isn’t necessarily a build for beginners though, as its M.A.D.ness will test your ability as a player to work with what you have to creative ends. Done well, it may be one of the strongest characters at the table. Done poorly? Well, I hope you don’t mind rerolling characters.

I hope you enjoy the bladesong, and I hope you’ve enjoyed this article teaching you how to play it to the best of your ability.

As always, happy adventuring.