Detect Evil and Good Spell Guide 5e

Whether you’re trying to root out a shapeshifting demon in your midst, locate a safe haven belonging to members of your holy order in a dangerous city, check the next room in the dungeon for lurking undead, or keep tabs on an invisible fey trickster, the 1st-level spell Detect Evil and Good might be the tool you need. 

This useful, widely misunderstood (and therefore criminally underrated) spell is one of my favorite ways to gather information when playing Dungeons & Dragons 5e, and it deserves a place on your character’s spell list. In this guide, we’re going to talk about how this spell works, who can cast it, and some of the best ways to use it in your ongoing D&D campaign.  

Spell Description 

When you cast this spell, you become aware of the presence and specific location of any aberration, celestial, elemental, fey, fiend, or undead within a 30-foot sphere around you. The effect lasts for the duration. You can also detect if a place within the spell’s range has been magically consecrated or desecrated. 

While the spell’s effects penetrate most barriers without issue, its ability to detect an aberration, a celestial, an elemental, a fey, a fiend, an undead creature, or magically consecrated or deconsecrated ground is blocked by 1 foot of stone, 1 inch of common metal, a thin sheet of lead, or 3 feet of wood or dirt.

How Does Detect Evil and Good Work? 

Detect Evil and Good is an interesting and oft-misunderstood spell. I feel like I see it getting written off for this reason — especially by players who are low level and might only have a few spells with which to make their way through the dangerous world of low-level play. 

This 1st-level divination spell has this reputation for the principal reason that it doesn’t actually, uh, detect whether something is evil or good? In fact, it gives the caster no insight into a creature’s alignment, although it can give some insight into someone’s true nature. Rather than telling you whether a creature is evil or not, the spell lets you know about the presence and location of any unnatural or extraplanar entities (specifically aberrations, celestials, elementals, fey, fiends, or undead) within range. 

However, just because the spell doesn’t actually detect whether a creature is evil or good — just whether it belongs to one of the creature groups that tend to have a leaning one way or the other, with the exception of fey that tend to be neutral — doesn’t mean it isn’t useful. 

Sure, you can’t use Detect Evil and Good to figure out if a human is harboring evil (or good) intentions, but you can sure as hell use it to figure out if they’re a demon in disguise. 

It’s also a great spell for sniffing out consecrated or desecrated ground, although that’s an area where the spell’s effectiveness is going to be more firmly in the hands of your GM. 

Consecration and Desecration 

Whether or not a piece of ground is made holy (consecrated) and then subsequently defiled by the forces of evil (desecrated) in Dungeons & Dragons isn’t always very clear cut — not to mention the fact that Detect Evil and Good specifies the consecration must be magical, meaning it’s unclear whether a simple temple would count as consecrated ground and whether burning one down without the use of magic would count as desecration in the spell’s eyes. 

The Hallow spell can create an area of consecrated ground, as could the power of something open ended like a cleric’s Divine Intervention feature. Desecration is a little harder as there’s no explicit way to desecrate something in the rules; if it’s just the opposite of consecrating something and consecration is a type of divine magical effect, then casting Dispel Magic or Antimagic Field might technically count as desecration, although I think that’s a rather boring interpretation. 

As a dungeon master, I think expanding the criteria for acts that consecrate a piece of land (or desecrate one) is a very good idea. 

Places of belief and worship are consecrated so long as they are in use or preserved. Places where a high-level cleric, druid, or paladin once cast a high-level spell or did something to honor their deity or oath (like slaying a great evil) could consecrate the ground for all eternity. Heck, what about ley lines or portals to appropriate planes or just anywhere someone performs a truly selfless act? Graveyards are the classic option — assuming priests regularly keep up the necessary blessings to prevent the dead from rising, that is. The world could be littered with consecrated ground, which makes desecrating it all the easier.  

I feel like desecrating something is different from just letting consecration run out or fade away. It’s a violation, an act that taints the original purpose of a place. Killing a cleric on a shrine to their god and painting the walls with their blood would be an act of desecration, destroying a holy symbol, performing acts contrary to a god, raising the dead, breaking ancient wards — all could be great acts of desecration. 

Also, I haven’t touched on this, but I’m definitely talking in terms of consecrated ground being good and desecration being an evil act. However, there are temples to all sorts of gods and all sorts of acts and places that are sacred to all sorts of entities in the D&D multiverse. It definitely depends on how you want to approach it as a GM, but a good-aligned cleric casting Revivify in the heart of a temple dedicated to the Raven Queen (a goddess of death) would almost certainly be considered an act of desecration. 

None of this is super integral to the way that this spell functions; it’s just interesting to me, and I think it’s the sort of answer you’ll want to have ready for your players because it pays to be consistent, and there just isn’t an official “right” answer out there. 

Who Can Cast Detect Evil and Good? 

Despite not actually having anything to do with the alignments evil and good, Detect Evil and Good is a spell that’s firmly in the wheelhouse of clerics and paladins. [As an aside, it’s also available as a bonus 1st-level warlock spell to all warlocks who choose the Pact of the Genie at 1st level.] 

Being primarily a paladin and cleric spell makes Detect Evil and Good especially appealing. These “divine” spellcasters have the ability to pray to their deities (or, like, just think about their oaths real hard in the case of the paladin?) for new spells each time they take a long rest, meaning it’s relatively easy to grab more situationally useful magic like Detect Evil and Good when you think it’s likely to be useful and ditch it when you want to focus your magical skillset on doing other cool stuff like burning heretics or whatever. 

Also, if you really really want this spell but don’t feel like taking a dip into paladin, cleric, or warlock, you can also take the Magic Initiate feat. This feat lets you choose a single cantrip and 1st-level spell to add to your character’s roster of magical abilities — although you can pick from anything, so there are probably better options out there. 

What’s the Best Way To Use Detect Evil and Good? 

While it’s no good as a way of detecting evil intentions or someone’s alignment, Detect Evil and Good is a remarkably good detection and information-gathering spell. 

If you find your party keeps getting tricked by shapeshifters, lured into traps by illusory duplicates, ambushed by skeletons that are just lying there, and otherwise put on the back foot by stealthy enemies, this is a truly excellent spell. It’s just a shame that it doesn’t detect monstrosities, or it would be the ultimate mimic detector. 

As it is, slaadi, imps, incubi, quasits, succubi, vampires, and yochlols are all shapechangers capable of taking another form, and there are others that can turn invisible (even though this spell won’t prevent the disadvantage from attacking an invisible target, it will still allow you make the attack when you otherwise might not be able to) and many many more that are just really sneaky. 

If you’re heading into an area where you suspect one of the types of creature flagged by Detect Evil and Good might be (any sort of tomb for the undead or extraplanar areas for the rest), then this spell’s long duration can make for a fantastic early warning system if you want to make sure nothing especially nasty gets too close.

Just make sure you don’t become overly reliant on it as an early warning system. Like I said, it doesn’t work on mimics.