Radiant Damage 5e dnd undead, resistance & vulnerability

The PHB defines radiant damage in 5e dnd as Radiant damage, dealt by a cleric’s flame strike spell or an angel’s smiting weapon, sears the flesh like fire, and overloads the spirit with power. It fails to mention the radiation part of it, but this is the gist of it. There are thirteen different types of damage 5e in Dungeons and Dragons.

Damage 5e Table

Slashing Damage	A longsword and a 5e greataxe inflict slashing damage
Piercing Damage	An arrow and spear inflict piercing damage.
Bludgeoning Damage	A club or a quarterstaff, and falling on your face all deal bludgeoning damage.
Poison Damage	A giant scorpion’s attack as well as the spell Poison Spray inflict poison damage.
Acid Damage	A flask of acid and a black pudding inflict acid damage
Fire Damage	The spell: Burning Hands, Fire Bolt, and Fireball all deal fire damage
Cold Damage	Ray of Frost 5e, Armor of Agathys, and Cone of Cold are all spells inflicting cold type damage
Radiant Damage	dnd Spells inflicting radiant damage 5e include: Sacred Flame and Moonbeam
Necrotic Damage	Inflict Wounds and Vampiric Touch deal necrotic damage
Lightning Damage	Lightning Bolt and Shocking Grasp inflict lightning damage
Thunder Damage	Thunderwave and Shatter both inflict thunder damage.
Force Damage	Eldritch Blast and Magic Missile are two common spells inflicting force damage
Psychic Damage	A mind flayer and the spell Vicious Mockery inflict psychic damage

Is radiant damage in 5e holy damage?

Radiant damage in 5e d&d is more like “Holy” damage, most frequently described as burning or blinding light. However, it is generally just flavor and doesn’t accurately heat the target up or set it alight or induce blindness (unless contrarily stated in the spell.)Though radiant damage can be seen as holy, there are traces of radiant damage in dnd 5e being dealt with as a type of radiation damage. Let us take some examples like concentrated UV rays or light with a shorter wavelength. The spell, sickening radiance is an example of the “unholy” or “radioactive” version of radiant damage.

Resistance, Vulnerability, and Immunity: 5e Damage Types

Many monsters or characters have abilities that make them resistant to fire damage or unprotected from acid injury. Each of these acts as a modifier to the total damage taken by that specific type of damage. If various types of damage are done, the damage modifier is mainly applied to the relevant damage rather than the sum.

Resistance: The target takes half the damage

Vulnerability: The target takes double damage

Immunity: The target takes zero damage

Does Radiant damage do extra damage to the undead in dnd 5e?

Radiant damage is the 5th Edition’s analog for “holy,” but it doesn’t always work in the rules the way you might expect. Radiant doesn’t necessarily refer to “holy” or vice versa, though they are often inextricably linked.

Radiant damage can be a possibility for creatures that have strong links to dark or unholy sources. However, not all beasts are treated in this manner.
Holy water, for instance, affects ALL fiends, undead, unless the creature description excludes them. 2d6 radiant damage is also done by holy water, but only to those creatures.

Radiant damage is not an issue for skeletons, the most common undead creature in your garden. It may be more beneficial to use a blunt weapon (which is what skeletons are vulnerable to) and keep your holy waters for undead and demonic creatures with less apparent vulnerabilities.
Radiant damage 5e is not a problem for zombies, ghouls, and other undead garden varieties.
Radiant damage can be done to shadows. Although Vampires are susceptible to radiant damage from sunlight exposure, they are not particularly vulnerable to any other forms of radiant damage.

Radiant damage generally is not effective against the majority of the undead. But, it is often false.
The best thing about 5e is the stat block. It tells you everything about the creature.
Radiant damage does extra damage if the stat block states “vulnerable radiant.”

Only creatures that are vulnerable to a particular type of attack will take more damage.
5e prefers to grant damage resistances as a rule.
Many undead is immune to many types of damage, including poison and nonmagical slashing.