Since some of the earliest days of Dungeons & Dragons, the Sun Blade has been an iconic magical weapon that any monster hunter, questing paladin, or cleric would be glad to have at their side.
Dungeon Master’s Guide, page 205
This item appears to be a longsword hilt. While grasping the hilt, you can use a bonus action to cause a blade of pure radiance to spring into existence, or make the blade disappear. While the blade exists, this magic longsword has the finesse property. If you are proficient with shortswords or longswords, you are proficient with the sun blade.
You gain a +2 bonus to attack and damage rolls made with this weapon, which deals radiant damage instead of slashing damage. When you hit an undead with it, that target takes an extra 1d8 radiant damage.
The sword’s luminous blade emits bright light in a 15-foot radius and dim light for an additional 15 feet. The light is sunlight. While the blade persists, you can use an action to expand or reduce its radius of bright and dim light by 5 feet each, to a maximum of 30 feet each or a minimum of 10 feet each.
Proficiency with a longsword allows you to add your proficiency bonus to the attack roll for any attack you make with it.
Cost: 10,000 gold pieces
Requires Attunement: Yes
History of the Sun Blade
The Sun Blade was introduced to Dungeons & Dragons in 1983 as a powerful, sentient artifact that played a key role in the game’s very first horror module: Ravenloft.
Called the Sunsword, this holy weapon was explicitly “stronger than any other against the evil in this land.”
Ages ago, Strahd employed a powerful magician to destroy the
sword. The first part of the process required that the hilt and blade
be separated, then destroyed simultaneously. However, before the
hilt and blade were destroyed, the magician’s assistant stole the
blade and attempted to flee from Barovia. Though his body was
later found in the woods, the blade was not with him. When it was
separated from the hilt, the blade took on the appearance of a
normal longsword.Ravenloft, AD&D I6, Tracy and Laura Hickman, 1983
Echoed in the weapon’s 5e design, the Sunsword was broken into two pieces by a powerful magician upon Strahd’s orders.
Its hilt, forged from platinum, lies within the castle and, if reforged into its original blade, becomes a +2 magical longsword that becomes a +3 magical weapon against the undead. When the Sunsword strikes a vampire, “sparks and flares”, inflicting an extra 10 damage with every blow.
It’s worth noting that the 5e reinterpretation of Ravenloft, The Curse of Strahd, also contains the Sunsword.
However, the weapon isn’t useless until reforged in this module because, even though it becomes immensely more powerful when reunited with its crystalline blade, the hilt of the weapon can still be used as a regular Sun Blade.
From the very get-go, the Sun Blade has been an explicitly anti-evil weapon with a penchant for taking down the undead – specifically vampires.
The weapon next cropped up in 2nd Edition D&D, this time officially called a Sun Blade, and with some minor mechanical alterations.
The Sun Blade (as opposed to the Sunsword) didn’t actually appear in an official module as a listed reward for players for another eighteen years, finally cropping up in City of Broken Idols for 3rd Edition.
In 5e, Sun Blades are an iconic weapon in the hands of a Paladin, Cleric, or any other servant of the light. They’re a great way to anoint the chosen champion of a particular good-aligned deity as that god or goddess’ mightiest hero.
A Sun Blade can be a particularly good item for Clerics who worship sun deities, like Pelor for Greyhawk and Lathander for the Forgotten Realms.
More broadly, from modern fantasy interpretations like Game of Thrones and The Scorpion King (you could even make the argument that the Sun Blade is D&D’s answer to the lightsaber) to ancient Sumerian Mythology and the Bible, flaming swords are a perennial trope in human storytelling.
Sun Blade Features
Let’s quickly break down a Sub Blade’s features, and explore exactly why this weapon is so powerful.
First, a flat +2 bonus is fantastic. It’s basically unheard of for weapons in D&D 5e to have a bonus of higher than +3, and those are super rare. Just about any melee-focused warrior would be happy to reach level 20 with a +2 weapon, and that’s before you factor in the Sun Blade’s other abilities.
While it uses the basic format of a Longsword, a Sun Blade is a finesse weapon, meaning that its presumably weightless blade can be effectively wielded by Dexterity-based characters like Rogues, Rangers, and maybe even a Bard from the College of Swords.
Dealing magical, radiant damage instead of mundane slashing or piercing is also extremely powerful. Many later-game enemies will have some form of resistance to non-magical forms of harm.
Also, because undead are such a common foe throughout D&D (maybe devils and demons lumped together come close in terms of ubiquity, but I think the ghouls, ghosts, skeletons, mummies, vampires, and liches still take the cake) inflicting some extra radiant damage when you hit an undead target is fantastic.
Because there is an explicit difference between light and “sunlight” in D&D 5e, the fact that the Sun Blade emits sunlight rather than regular light can be an absolute game-changer when you’re fighting Drow, Duergar, and – of course – Vampires.
Where to Get a Sun Blade
Because of their rarity and probably religious significance, it’s honestly unlikely you’ll be able to just wander into a shop and pick one up.
While it’s very possible that a player will carry their +1 magic sword from 3rd level all the way through to the end of the game, most DMs (myself included) like to give each player a “capstone” item, either when they pass level 10 or when it’s apparent that the campaign is headed towards its conclusion.
Think of it as Luke’s green lightsaber in Return of the Jedi; it’s a weapon that signifies the character has grown enough to be ready for the final confrontation with evil.
If you have a character whose vibe fits with the Sun Blade, it can make a perfect capstone item for them.
The other reason I wouldn’t make the Sun Blade available in a shop is that, for a mere 10,000 gold pieces, it’s hugely underpriced.
For example, a Weapon of Warning literally just nullifies the effects of enemy surprise rounds and costs a staggering 50,000 gold.
If you do want to make Sun Blades readily available for players to buy, consider making the location in which the shop exists utterly alien, or make the powers of the Sun Blade pretty essential to survival in that area.
A magic item shop in the deepest, darkest recesses of the Underdark. The blades are forged by an enslaved celestial smith and the fact that pretty much everyone carries one is the only reason this community still survives in the darkness.
It’s much more likely and (I think) more satisfying to put a Sun Blade into the world in your players’ path, making its acquisition feel like it was earned through deed rather than cold, hard cash.
Grant a champion of the sun god a sacred Sun Blade as the rallying symbol for an imminent holy war.
Equip an ancient order of lich-slaying knights with these blades. Terrifyingly, the order was seduced by a lich and now serves their dark master’s commands.
Embed it in the petrified skull of a Tarrasque, still crackling with fire. Warn the players that removing the blade will have disastrous consequences. If they get greedy and pick up the blade, the Tarrasque begins to awaken.
The Sun Blade is a fantastic item for any Melee-Focused class that favors either Strength or Dexterity, meaning that anyone from a Cleric or Paladin to a swashbuckling Rogue could make excellent use of this iconic blade.