Aerilwyn's Guide to Bladesinging

The Bladesinger is one of the most fun playstyles, effortlessly combining swordplay and sorcery in a single, batteries-included package. Building characters with this subclass presents many hard choices, and there are several intricacies that needs to be taken into account.

Class Features

For this discussion, I will be assuming you are building a Bladesinger that attacks using Dexterity (alternative builds are discussed later).

Training in War and Song

There are basically three choices to make for which weapon to gain proficiency with:

Rapier: d8 is the biggest damage die you can get, which is nice. Magical rapiers are not very common, but they do exist. Does not give you the option to dual-wield unless you have the Dual Wielder feat.
Shortswords: d6 is only one less damage on average than the rapier's d8. Having the Light property gives you access to two-weapon fighting, which can be nice for early levels, but you need to figure out how you are providing your spell components if you do so. In my experience, DMs are more likely to hand out magical shortswords than rapiers, and they are more common in pre-written adventures.
Whip: While the d4 damage die is annoyingly small, Reach is a pretty big benefit. With a whip, you control a much larger space on the battlefield, and can attack most enemies without entering their melee range. However, this might not work well with Booming Blade (see the discussion on Spell Sniper below).

Bladesong

This is why you are here. There is a lot to talk about here, but we will make sense of it.

Firstly, the restrictions. No medium or heavy armor or shields invalidates several multiclass options. Not allowing two-handed weapon attacks is also something we can handle, since there are no Finesse two-handed weapons. If we could make attacks with two hands, the Revenant Blade feat would suddenly become very interesting.

As for the benefits, the AC increase is one of the biggest flat AC boosts in the game, and stacks with your armor, effectively giving you an AC of 12+dex+int with Studded Leather. This can easily become 20+ by the midgame, and there are spells that can boost it even higher.

The walking speed increase is nice, especially if we can stack it with other movement speed increases.

Extra Attack

Bladesingers get a unique version of Extra Attack, at the cost of getting it one level later. Being able to replace an attack with a cantrip is excellent. The main choice here is between Booming Blade and Green-flame Blade. I usually prefer Booming Blade, as it provides some control and does not rely on a second target being nearby. You can also replace an attack with Firebolt or another ranged cantrip, but beware of attacking with ranged attacks when you have a target within 5 feet of you, as the attack will have disadvantage. You could also use a save-based cantrip like Mind Sliver if you want to debuff the enemy for your friends or to cast an important spell at them on your next turn.

Song of Defense

Possibly the least exciting feature a Bladesinger gets. This feature lives in the shadow of Shield and Absorb Elements, which only take 1st-level spell slots. However, it is far from useless - just make sure not to use it when Shield or Absorb Elements would be better.

Song of Victory

A much-welcome boost to our melee damage. However, at this level you have gained access to some of the most powerful spells, and you should not neglect to use them to deal a little bit of extra melee damage.

General Wizard Features

Wizards do not get many class features outside of their exceptionally good spell list. Arcane Recovery lets you get a few spell slots back on a short rest, which is always nice. At very high level, a Bladesinger's Spell Mastery is most likely best spent on Shield or Silvery Barbs and Misty Step. Absorb Elements is also good, but is less generally applicable. Shadow Blade is likely to be outclassed at its base level if you have a magical weapon. For the capstone, Spell Mastery, Counterspell is the easy choice to make. Hypnotic Pattern, Fireball, Haste, and Dispel Magic are also decent choices. For both of the high-level features, focus on spells which you do not want to upcast.

Ability Scores

Bladesingers need both high Dexterity and high Intelligence, and a decent Constitution. This leaves quite little wiggle room when it comes to your initial ability scores.

The choice whether to focus on Dexterity or Intelligence with your ASIs merits some discussion. Focusing on Dexterity will increase your effectiveness as a melee combatant, and higher Intelligence will make you a better spellcaster.

Increasing your Dexterity modifier by 1 gives you:

+1 to hit and damage with weapons
+1 AC at all times
+1 to Initiative
+1 to Stealth, Acrobatics, and Sleight of Hand

Increasing your Intelligence modifier by 1 gives you:

+1 to hit with spells, and +1 spell save DC
+1 AC during Bladesong
1 additional prepared spell
+1 to Arcana, History, Nature, Religion, and Investigation

Almost all these points to Intelligence being the priority:

Missing with a weapon attack, while not good, is far less impactful than missing with a spell, which are a limited resource.
When you have Bladesong active, both dex and int have the same effect on your AC. When it is not active, you are not likely to want to be in melee regardless.
The additional prepared spell is very nice, especially as you head into higher levels when your spellbook grows huge.
You will not be the worst at Stealth in almost any group, and you have advantage on Acrobatics checks during Bladesong. However, you might very well be the only one in a party with decent Intelligence. Being even better at something no one else does well is far more valuable than being slightly less bad at stealth than the rogue or ranger.
You are far more likely to find a magic weapons with a bonus to attack and damage rolls than something that increases your spell save DC.

You can definitely also build an effective Bladesinger that focuses on Dexterity over Intelligence. If you choose to go down that route, select spells that are utility based and are not as reliant on your enemies failing saves.

Races

For this section, I will be assuming that the Tasha's rules about Customizing Your Origin are in effect, as well as a free feat at 1st level.

Almost all races will do the job, but some provide benefits that are extra useful.

Wood Elf

High Elf

Eladrin and Shadar-kai

Non-spell Misty Step several times per day, with good riders? Yes, please. These races are both near the top of the list. A more hidden benefit are their Trance feature, which allows us to change a weapon proficiency on a long rest, which is handier for a Bladesinger than almost any other build.

Half-elf

The +2/+1/+1 is excellent for Bladesingers, as we need several ability scores to be high.

Mountain Dwarf

Satyr

Tortle

While it might look like an unorthodox choice, having your AC independent from your Dexterity modifier allows you to be a Strength-based Bladesinger instead. This is not better in itself (in fact, it might be slightly worse), but it makes it far more possible to make certain multiclasses work, in particular Paladin. The other features are not very exciting.

An often overlooked benefit of being able to focus on Strength is the ability to use staffs in combat. There are several high level wizard staffs that come with both a bonus to melee attack rolls and a selection of spells. While it is possible to use these in the offhand, this reduces the number of magic items needed to achieve full power.

Harengon

Tabaxi

Spells

Multi-classing

This section is mainly concerned with dips - taking one or two levels to access some key feature of another class early, and then going Bladesinger for the rest of your career.

Bladesingers are already dependant on several different ability scores, and multiclassing usually exacerbates this problem, but some of them might still be worth it. However, it is important to keep in mind that multiclassing is by no means required to build a good Bladesinger, but could a way to make a more unique build, especially if you play with rolled stats and manage to get a very good array.

Artificer

Starting with one level of artificer is good, although not as good as for other wizards since we cannot use medium armor or shields. One artificer-only magic item of note is the All-Purpose Tool, which could let you access an Intelligence-based version of Shillelagh - a very interesting spell to get.

Pros:

(As a starting class) Proficiency with Constitution saving throws and Thieves Tools
Does not delay your spell slot progression
Intelligence-based Guidance, Cure Wounds, Faerie Fire

Cons:

Medium armor and shields are wasted for a Bladesinger
Annoying spell component juggling

Barbarian

Surprisingly decent if you can manage the Strength requirement. While you technically can have Rage and Bladesong active at the same time, the benefit is dubious at best, as you lose access to your spellcasting, including your cantrips. Also requires you to be a Strength-based Bladesinger to gain the benefits of Rage. However, the remaining features are quite nice if you start with one level of barbarian: Proficiency with martial weapons and Constitution saving throws, and Unarmored Defense that keys off Constitution and Dexterity - ability scores you would build for anyway. This one deserves more analysis.

Bard

A Bladesinger gains little with a dip in bard.

Cleric

Same as with the Artificer, the armor proficiencies are wasted. Some of the subclasses have good features, and it will not delay your spell slot progression.

Druid

The most likely Druid dip is Stars, as a way to protect your Concentration checks with the Dragon form. Having several bonus action buffs at the start of combat is very annoying. Probably not worth it, but could be a fun concept.

Fighter

Easy requirements, and best taken as a starting class for proficiency with martial weapons and Constitution saves. Getting a fighting style is decent, especially if you intend to dual-wield. Also opens up the possibility to take a second level later for Action Surge, which is undeniably awesome, but comes at the cost of a whole tier of spell progression.

Monk

The monk synergizes surprisingly well with the Bladesinger. You gain the ability to use Dexterity to attack with staffs - and several good magic wizard staffs have bonuses to melee attacks. With a +2 Wisdom or higher, you do not fall behind in Armor Class (compared to Studded Leather) since you need to use the Monks Unarmored Defense to gain the benefits of the Martial Arts feature. This dip is probably best taken after level 6, as you need to take the Attack action (which you can not combine with Booming Blade before level 6) to use the unarmed bonus action attack. It is also possible to get a second level in monk, which gives even more movement speed, as well as the ability to Dash, Disengage, or Dodge as a bonus action twice per short rest (using your highly limited Ki points for Flurry of Blows will not be worth it). If you can get the proficiency from somewhere, this also lets you use almost any type of weapon with Dexterity with the Dedicated Weapon optional class feature. Since you still cannot attack with two hands, this might not be a huge gain.

Paladin

Ranger

Rogue

Two levels in Rogue gives you access to Cunning Action.

Sorcerer

Warlock

Feats

The Bladesinger wizard might be one of the most feat-hungry subclasses in the entire game - wanting both the martial feats and the spellcaster focused ones.

S tier

Excellent feats that improve you across the board. You are going to want some of these. It is possible to do well without them, but you will feel their absence.

Resilient: Constitution

The other major way of protecting your Concentration, which also gives you a slight Constitution boost. With this feat, it is not hard to get a +9 or higher bonus to your Concentration checks while Bladesong is active, letting you automatically pass Concentration checks unless the damage taken was very high. Another, often overlooked, benefit to this feat over War Caster is that it impacts other Constitution saves you make. Constitution saves come up a lot and are usually quite nasty, and do not seldom have Incapacitating effects attached to them, which end your Bladesong.

War Caster

You will often be in the thick of it, and protecting your Concentration is extremely important. Advantage on your Concentration checks goes a long way towards that. Of the other benefits, unless you are dual-wielding, you don't have a problem with components since you cannot use a shield regardless. If you are dual-wielding, you probably still want a way to use spells that require a material component, which this feat does not solve. On the other hand, the spell opportunity attacks is great - letting you cast Booming Blade which instantly deals its full damage, or Hold Person to keep them in range.

Which to take of War Caster and Resilient: Con is mostly personal flavor. War Caster is the more offensive choice, but Resilient is useful for regular Constitution saves. I find Resilient better if you have an odd Constitution score, otherwise War Caster, but it is close and neither choice is wrong. If you can find room for both, your Concentration will be almost unbreakable while Bladesong is active.

Telekinetic

One of the best choices to round out an odd Intelligence score. Mage Hand is a great cantrip, but it can be hard to fit among your initial choices. The ability to have an invisible hand makes this feat the best way to acquire that cantrip outside of a 3-level Arcane Trickster dip. I usually find I would rather have another cantrip than the extra range on Mage Hand, and thus don't bother taking Mage Hand if I plan on taking this feat.

However, the best benefit of this feat is the shove. By default, Bladesingers does not have a continually useful bonus action, and this feat is an excellent way to remedy that. Five feet might not sound like much, but it is incredibly helpful to position enemies for area-of-effect spells, or push them out of position in general. Perhaps the greatest use of the feat however, is to move your squishy allies away from the reach of enemies, letting them run away without taking opportunity attacks. Unlike using it on an enemy, using it on an ally cannot fail. Moving your allies is also exceptionally useful against enemies that grapple your allies, as any forced movement instantly breaks a grapple. Best of all, you can do this on every turn without using any resources.

Combining a half feat with an excellent cantrip and an unlimited highly useful bonus action makes this a top contender, especially if your Intelligence is odd.

A tier

These feats are very good, but not quite game-changing.

Elven Accuracy

This feat goes a long way towards making sure you always hit with your Booming Blade. Bladesingers have several sources of reliable advantage that let you benefit from this feat:

Your Familiar can use the Help action to give you advantage on the first attack you make on every turn.
Shadow Blade gives you permanent advantage in dim light or darkness.
If the target fails their save against Hold Person, they are in for a world of hurt.

A 'downside' to this feat is that if you had advantage, chances were you were going to hit anyway. If you can find a way to increase your critical hit range, or a way to add more damage dice on a crit, the value of this feat rises significantly.

Mobile

Both the movement speed and avoiding opportunity attacks are great. Combined with the extra movement speed from Bladesong, you can play with a much more hit-and-run style, and often your enemies will not be able to retaliate at all. Being able to strike a lone enemy and run away also increases the chances of them taking the extra damage from Booming Blade.

Strixhaven Initiate

For the first level spell, do not be tempted to take an additional wizard spell - instead try to acquire a spell scroll and scribe it into your spell book.

The Quandrix college in particular is excellent, letting you access two very useful cantrips in Guidance and Mage Hand, as well as another first-level spell. From the Druid spell list, there are a couple of stand-out choices:

Healing Word: This feat is one of few ways to get this spell and cast it using Intelligence.
Goodberry: If no other party member has this spell, it can be very useful to have.
Faerie Fire: Advantage is very strong, and sharing it with your friends with your excellent concentration checks? Yes please.

The other colleges are less interesting, but Silverquill or Prismari offers access to the Bard spell list, from which you could take Healing Word, Faerie Fire, or Dissonant Whispers. If you pick Lorehold or Silverquill, you can pick a spell from the Cleric spell list. Standout spells are Bless, Healing Word, and Shield of Faith.

Lucky

Lucky is always good, and can provide a mix of better offense and protection for your Concentration.

This feat can act like a limited version of several other feats at the same time. When you use it on your concentration checks, it acts like War Caster. When you use it on your attacks, it acts like Elven Accuracy.

Fey Touched

Misty Step is excellent for a Bladesinger, who can often find themselves out of position. For your 1st-level spell, there are several good options, including Bless, Dissonant Whispers, Hex, and Gift of Alacrity. Focus on getting spells not on the wizard spell list, since you can scribe wizard spells you find into your spell book.

Metamagic Adept

The top choices for this are Subtle Spell and Quicken Spell. Subtle makes you able to cast spells in social situations far easier. Quicken is mostly useful with powerful debuff spells, such as Hold Person/Monster. The major drawback is the very limited pool of Sorcery Points - if you Quicken a spell you only get a single use per long rest.

B tier

If you find yourself with spare ASIs, you could consider one of these feats.

Spell Sniper

RAW has gone back and forth on whether this works with Booming Blade when you use a Reach weapon. Talk to your DM to learn how this interaction is ruled at your table. If they allow 10-foot Booming Blades, this feat becomes quite more desirable, otherwise it is probably a pass.

Tough

Taking this feat will essentially boost your hit die from a d6 to a d10. While HP tanking is rarely the way to go, this is an option if you are struggling.

Artificer Initiate

Taking Guidance and Intelligence-based Cure Wounds sounds excellent, but Strixhaven Initiate is better in almost any situation, unless you want to trade a cantrip for a tool proficiency for some reason.

C Tier

Specialized feats that require the circumstances to be correct for their benefits to shine.

Fighting Initiate

Dueling might sound good, but increasing your Dexterity (giving you +1 to hit, and +1 to AC as well as +1 to damage), will be a far better choice.

Two-weapon Fighting is better, and might be worth a feat for a dual-wielding Bladesinger.

Gunner

This lets you use your ranged spell attacks from melee range, as well as give you a Dexterity boost. Regardless, Booming Blade should be better damage than Firebolt or some other damage cantrip at almost all levels. If you don't want to use Booming Blade, you can pick a saving throw based cantrip such as Mind Sliver instead.

F Tier

Trap choices that should be avoided if you can.

Weapon Master

Do not take this unless you actually have weapons you would like to use that you cannot use, and even then I would look into downtime training first, or even multi-classing into Fighter or Cleric instead. Since you are most likely limited to Finesse weapons, there arent that many choices here that make sense.

Defensive Duelist

While this might sound exactly like something a Bladesinger would be very good at, the Shield spell is strictly better, as this feat only works against a single attack per round.

Magic Items to Aim For

While you do not always control what items you will receive, this is list of some of the ones highest on the Bladesinger's wish list. This list is also for DMs who are looking for good loot to hand out - your Bladesingers will go to the ends of the earth for these items.

In general, AC bonuses are very valuable. Bladesingers also usually prefer weapons with a bonus to hit rather than bonus damage or other effects. Do not expect to receive (and DMs, do not give) all items on this list, one or maybe two are enough.

Sun Blade

Literally everything the Bladesinger wants. +2 finesse longsword (that uses shortsword proficiency) with a magical twist and potential bonus damage? Sign me up!

Moon Blade

If you can get your hands on a Moon Blade with the Finesse property, this could be an incredible weapon with equally incredible roleplay potential. Rolls on the the table should be awarded after major story points.

Glamoured Studded Leather

This fun armor has some neat roleplay implications. I particularly like fighting in a ball gown or jester suit or some other silly garment, but it is also handy for infiltration and general shenanigans.

Bracers of Defense

For Bladesingers who rely on Mage Armor, these bracers are incredibly powerful, equivalent to +3 Studded Leather, a legendary item.

Wand of Binding

A nice balance between offensive tools and some non-AC defensive utility makes this a good off-hand for any Bladesinger.

Illusionist's Bracers

While they are not as good as for a Warlock, these bracers are nevertheless incredibly good for a Bladesinger, giving an entire extra Booming Blade per turn.

Cloak of Displacement

This cloak pairs almost too well with the high AC of the Bladesinger. DMs, if you give this, do not give ANY other items that boost the Bladesinger's AC.

Mantle of Spell Resistance

This makes you an excellent mage-hunter, and able to go toe-to-toe with spellcasters well above your level.

Goggles of Night

These are important if you rely on Shadow Blade and do not have darkvision from your race. There are also other items with a similar effect, such as the Shadowfell Brand Tattoo or the Robe of Eyes.