D&D 5E Arcana Checks

[BlivetWidget]

Inspired by the the original post on medicine checks, I decided it might be useful to go through the published material and put together a short list of the things arcana checks are being used for.

This was not as simple as I thought. Arcana is sort of a catch-all skill for anything 'weird' that doesn't fit into another category. The effects are often very specific, making it difficult to summarize the list. A medicine check can let you stabilize a dying creature. An arcana check can let you study a destroyed construct's components to determine how to create one yourself (this kind of specificity also makes the descriptions a lot wordier).

I think someone who just reads the PHB's description of the arcana skill is missing a lot of interesting things that WotC intends it to be used for. They use arcana for identify / detect magic / knock (there is still value in the spells of course, because they guarantee success), finding/disabling magic traps (this is briefly covered in the DMG), determining how to use unusual magic devices/symbols, and figuring out how to use/control constructs and machinery.

I counted 217 arcana checks across all the published 5e adventures I could look through. A DC of 0 means that no roll is required, simply proficiency. Some of these entries can be easily combined (there is a lot of trap checking / disabling), but others are rather specific and I will have to really think about how to simplify them to avoid losing too much information.

Spoiler: the data

Activity	DC	Source
Recall lore about spells, magic items, eldritch symbols, magical traditions, the planes of existence, and the inhabitants of those planes.	varies	PHB
Detect or disarm a magic trap	varies (trap DC)	DMG
Copy a spell scroll	10 + spell level	DMG
Identify a spell (advantage if on your class spell list)	15 + spell level (adv. if on class spell list)	XGE
Craft a magic item	0	XGE
Scribe a spell scroll	0	XGE
Discover the presence of inconspicuous spells	varies	Sage Advice Compendium
Contested roll: determine which of two equal spells wins (e.g. two mage hands)	0	Live games run by Chris Perkins
Identify a spell from glimpsing its effects on a creature	19	BGDiA
Determine the function of magic symbols	0	BGDiA
Determine how to activate an unfamiliar/unusual magic item	10	BGDiA
Recognize a curse and how to end it	15	BGDiA
With study, recognize a curse and how to end it	0	BGDiA
Determine the cause of a magic vehicle's malfunction	15	BGDiA
Identify the schools of magic associated with symbols	15	BGDiA
Recall lore about a fiendish structure	25	BGDiA
Determine the function of unusual/unfamiliar magic items	14	BGDiA
Determine how to break a curse	12	BGDiA
Study a broken machine for 1 hour to determine its purpose	20	BGDiA
Identify a magical effect from observing a creature	15	BGDiA
Study a broken machine for 1 hour to determine its purpose	20	BGDiA
Determine the function of unusual/unfamiliar magic items	10	BGDiA
Determine the function of unusual/unfamiliar magic items	20	BGDiA
Determine how to operate a construct	17	BGDiA
Identify a spell from its effects on a creature	18	CoS
Identify the general intent of a spell from overhearing part of it	14	CoS
Determine a teleportation circle is flawed and dangerous	15	CoS
Study bookshelves of rituals for 1 hour to determine if they are genuine	12	CoS
Decipher a magic inscription in a language you understand	15	EKDC
Decipher a magic inscription in a language you do not understand	25	EKDC
Recognize the nature of the connection between a construct and its controller	10	EKSDW
Identify statues of a diety of magic	15	EKSDW
Identify the school of magic associated with symbols	15	EKSDW
Notice magical emanations from a hidden portal and recognize the type of magic	15	EKSDW
Identify a disguised fiend	20	EKSDW
Determine a studied item is cursed	25	GoS
Study an abstruse book for 8 hours to understand its general subject	20	GoS
Recall lore about an obscure ritual	14	GoS
Research arcane lore (15 - days spent researching)	10-15	GoS
Identify a spell from its effects on an object	16	GoS
Identify an aberration	15	GoS
Determine the function of magic symbols	18	GoS
Recognize a draconic creature	15	HotDQ
Recognize a magic item	15	HotDQ
Use an unfamiliar and unusual magic item	15	HotDQ
Sense the presence of a spirit controlling a structure	15	HotDQ
Determine how to operate a construct	10	KW
Repair a construct	15	KW
Determine unique features of a fiend	12	LLoK
Open a magic gate	15	LLoK
Hold a knowledgeable discussion on magical matters	0	LLoK
Deactivate a magic hazard	15	LLoK
Complete the creation of an invention using notes	18	LLoK
Activate an unfamiliar and unusual magic item	16	LLoK
Open a magic gate	15	LLoK
Open a hatch on an operating construct	15	LLoK
Recognize an astral silver cord	15	LLoK
Decipher notes for operating a legendary magic item	13	LLoK
Complete the creation of an invention using notes	18	LLoK
Identify the planar origins of unusual materials	14	LLoK
Activate an unfamiliar and unusual magic item	16	LLoK
Recognize an astral silver cord	15	LLoK
Activate an unfamiliar and unusual magic item	14	LLoK
Activate an unfamiliar and unusual magic item	16	LLoK
Complete the creation of an invention using notes	16	LLoK
Determine the purpose of an alchemical apparatus	0	LMoP
Recognize a magic symbol	10	LMoP
Sense the aura of a magic workshop	0	LMoP
Identify the source of a magic aura	15	LMoP
Study notes for an hour to discover they constitute a spellbook	0	OotA
Study notes for an hour to discover they contain usable alchemical recipes	15	OotA
Examine symbols to determine related dieties	16	OotA
Reveal the nature of a curse and how to end it	12	OotA
Study notes for 8 hours to understand the 2 rituals they describe	0	OotA
Notice an object is leaking magical energy and how to activate it	0	OotA
Notice that a creature is from another plane	15	OotA
Recall learning details of an event that has not happened in 200 years	20	OotA
Activate an unfamiliar and unusual, clockwork magic device	15	OotA
Open a magically-locked door	20	OotA
Study books and scrolls for 10 minutes to identify the 5 most valuable	15	OotA
Determine characters are under the effect of Astral Projection	13	OotA
Determine if an action is required for a ritual to succeed	20	OotA
Determine that a creature was raised as undead by a unique ritual	10	OotW
Determine the area and type of magic that that runes can emit	16	OotW
Suppress magic traps for 1 minute	10	OotW
Deactivate a magic hazard	12	OotW
Sense the magic of a hidden planar gate	18	OotW
Examine runes to determine related dieties, general message, and powers	15	OotW
Recognize the ritual purpose of a particular sigil	10	OotW
Recognize that seemingly normal damage (such as fire) was caused by magic	15	OotW
Examine the results of a failed ritual to determine its purpose	10	OotW
Recall the effect and duration of magical effects caused by creatures	11	OotW
Disrupt an open portal	15	OotW
Examine a body to find evidence of magical damage	10	OotW
Understands the purpose and weaknesses of magic traps	10	OotW
Discern the effects of activating a magic trap	15	OotW
Disable magic trap	15	OotW
Open magic lock	15	OotW
Understand the properties of a magic item and how it was created/modified	10	OotW
Disrupt a magic item	15	OotW
Reveal, with a few minutes of study, a magic item's properties	0	OotW
Determine command phrase for magic item	12	OotW
Determine creature is becoming undead	15	OotW
Determine how long until a creature becomes undead	20	OotW
Stop a creature from becoming undead	15	OotW
Determine how to open a puzzle door	10	OotW
Disable a magic hazard	15	OotW
Study a destroyed construct's components to determine how to create one yourself	0	OotW
Determine a door is magically trapped	14	OotW
Disarm magical trap	13	OotW
Determine how to alter a portal to confuse pursuers	14	OotW
Alter a portal to confuse pursuers	12	OotW
Determine how a portal system works	0	OotW
Identify a magic plane/dimension	12	OotW
Convincingly fake a ritual	11	OotW
Determine the source of a curse	12	OotW
Detect a magic trap	16	OotW
Disarm a magic trap	14	OotW
Determine a creature has been magically tainted, and which part of them is corrupted	12	OotW
Open a magically-locked door	15	OotW
Identify a magic plane/dimension	12	OotW
Disable a magic trap	15	OotW
Determine how to stop an ongoing ritual	0	OotW
Gain control of part of an ongoing ritual	15	OotW
Incorporate/remove a component of an ongoing ritual	12	OotW
Begin or end an ongoing ritual effect	12	OotW
End an ongoing ritual	15	OotW
Notice that a landscape was shaped by magic	15	PotA
Study a workshop to determine the types of magic it was used for	0	PotA
Recognize the purpose and functional state of ritual circles	15	PotA
Recognize a creature	12	RoT
Determine the spell used by a creature's innate spellcasting	15	RoT
Determine the purpose of a complex apparatus after studying for a day	20	RoT
Recognize dried up ink as a type used for magical writing	0	RoT
Discover a thin line of magical salt	12	RoT
Determine an object is part of a construct	15	SKT
Determine an object has magic properties	15	SKT
Determine that symbols are magical	0	SKT
Determine how long a portal will remain open	17	SKT
Identify a wondrous artifact	18	SKT
Determine how to break a psychic link	15	TftYP
Determine the school of magic associated with symbols	0	TftYP
Determine the nature of a magic gate	10	TftYP
Disrupt a magic gate once its nature is understood	15	TftYP
Use an unfamiliar and unusual magic item	15	TftYP
Determine that magic runes are gibberish	0	TftYP
Identify the magic effect of symbols	15	TftYP
Suppress a magic trap	15	TftYP
Determine the magic effect of runes	15	TftYP
Suppress the magic effect of runes (requires 3 consecutive successes)	15	TftYP
Determine the nature of a rift	10	TftYP
Determine a rift is dangerous	15	TftYP
Determine how to distrupt a circle's magic for 1 minute	10	TftYP
Perform unfamiliar and unusual ritual	15	TftYP
Determine the effect of magic runes	15	TftYP
Destroy magic runes	20	TftYP
Determine the details of a ritual from inspecting its components	20	TftYP
Activate a magic circle and learn the details of its effects	20	TftYP
Discern the value of ritual ingredients	15	TftYP
Discern the value of ritual ingredients	15	TftYP
Discern how to use magic symbols	10	TftYP
Suppress the magic effect of symbols for 1 minute	10	TftYP
Suppress the magic effect of symbols for 2 minutes	15	TftYP
Activate a magic gate	20	TftYP
Activate a golem	15	TftYP
Discern the value of ritual ingredients	15	TftYP
Discern the value of ritual ingredients	15	TftYP
Discern how a magic item works and how to disable it	15	TftYP
Discern how to disable a magic item	10	TftYP
Disable a magic item (requires 3 consecutive successes)	15	TftYP
Determine that a magic item is failing	13	TftYP
Determine the nature of a secret magic trap	20	TftYP
Recognize teleportation circle and memorize its sigils	0	ToA
Identify a construct	10	ToA
Use a teleporter intended to only allow another creature's use	20	ToA
Identify a fiend	15	ToA
Recall lore about planar vortices	10	ToA
Recall lore about a magic item	15	ToA
Determine a magic item's purpose and current use	20	ToA
Determine how to destroy a magic item	25	ToA
Identify a phylactery	15	ToA
Determine how to end a magic effect	17	ToA
Reconstruct a summoning circle	15	WDDotMM
Determine that magic is being faked	10	WDDotMM
Identify a spell from the damage it caused	19	WDDotMM
Identify a magic item	15	WDDotMM
Identify an aberration	15	WDDotMM
Determine how to use a magic item	15	WDDotMM
Determine the purpose of magic symbols	20	WDDotMM
Determine the properties and effects of a magic circle	20	WDDotMM
Determine the properties and effects of a magic circle	20	WDDotMM
Determine the purpose of magic symbols	20	WDDotMM
Determine the properties and effects of a magic circle	20	WDDotMM
Recognize the school of magic represented by magic symbols	15	WDDotMM
Determine the purpose of an unusual artifact	30	WDDotMM
Identify spells being researched from incomplete notes	16	WDDotMM
Identify an aberration from its skull	15	WDDotMM
Identify the purpose of an unfamiliar and unusual magic item and how to use it	14	WDDotMM
Identify a plane	20	WDDotMM
Identify a spell from the damage it caused	16	WDDotMM
Determine the properties and effects of a magic circle	13	WDDotMM
Identify a phylactery	15	WDDotMM
Determine the function of magic symbols	15	WDDotMM
Attune to a particular legendary magic item	0	WDDotMM
Determine the properties and effects of a magic portal	20	WDDotMM
Determine the function of magic symbols	18	WDDotMM
Determine the function of magic symbols	20	WDDotMM
Identify the details of a creature transformed by True Polymorph	19	WDDotMM
Recognize the school of magic represented by magic symbols	10	WDDotMM
Recognize the school of magic represented by magic symbols	10	WDDotMM
Recognize the school of magic represented by magic symbols	10	WDDotMM
Repair a damaged construct	0	WDDotMM
Identify a spell from the sound of its effect	13	WDH
Determine the function of a magic item	10	WDH
Determine the magic effect of symbols and how to end it	15	WDH
Determine the magic effect of symbols and how to end it	15	WDH
Determine the school of magic associated with symbols	15	WDH

Update: I've spent some time consolidating the list down to 37 items. I believe this short list loses only a little bit of fidelity compared to the above list, though obviously a few hyperspecific details had to be dropped. If anyone feels like the list could be further consolidated, feel free to let me know. I chose not to consolidate the first 8 items because they are rules as written, while the remaining represent how WotC believes those rules should be implemented (by doing so themselves in their adventures).

Spoiler: the short list

Items with a * require proficiency in Arcana and tend not to be used as skill checks

Recall lore about spells, magic items, eldritch symbols, magical traditions, the planes of existence, and the inhabitants of those planes

Detect or disarm a magic trap

Copy a spell scroll

Scribe a spell scroll*

Craft a magic item*

Advantage using (and learn more from) Alchemist's Supplies, Calligrapher's Supplies, Herbalism Kit, and other tools*

Identify a spell or magic effect during casting (advantage if on your class spell list)

Discover inconspicuous evidence of magic use, such as spell effects/damage on a creature/object/landscape

Examine the results of a failed ritual to determine its purpose

Hold a knowledgeable discussion on magical matters*

Compete to determine which of two equal spells succeeds (e.g. mage hands)

Detect, suppress, disable, or understand the effects of a magic hazard/curse/corruption/circle/portal/lock

Identify and recall features/ magic effects / places/ planes / items / body parts related to aberrations, constructs, fiends, necromantic undead, or extraplanar creatures

Determine a magic item's properties*

Determine a magic item's command phrase / how to activate it

Determine the purpose of an alchemical or mechanical apparatus*

Use, disable, or determine the purpose of an unusual magic item, apparatus, or mechanical device

Use a magic item intended to prevent you from using it

Study a magic workshop to determine its purpose*

Sense the aura of a nearby magic item/area/portal and know the type of magic*

Locate a magic item/area/portal from its aura

Sense the presence of a spirit inhabiting a structure or object

Determine how to control/disrupt/repair a construct or machine by examining it or its pieces

Study a destroyed construct's components to determine how to create one*

Build an invention using someone else's notes

Determine the function/validity/school/deities/message represented by magic symbols*

Determine how a portal system should be used*

Determine where a portal leads or how long it will remain open

Study notes to discover they contain spells or rituals*

Study an abstruse book to understand its general subject

Recognize a teleportation circle and memorize its sigils*

Identify a magic plane/dimension

Identify the planar origins of unusual materials

Convincingly fake or recognize a fake spell/ritual

Alter or disrupt an ongoing ritual

Perform an unfamiliar or unusual ritual from notes

Determine the purpose and value of magic items, ingredients, ritual components, or related incidental materials (e.g. dried spell ink)

 

[iserith]

Good effort! In my view, the length of this further argues against consulting such lists though when determining if an ability check is called for in one's game, which skill proficiency may apply, and which DC is appropriate given the player's stated approach to the goal. Or providing such a list to the players.

Interesting to look at in any case, so thanks for posting it.

 

[BlivetWidget]

Good effort! In my view, the length of this further argues against consulting such lists though when determining if an ability check is called for in one's game, which skill proficiency may apply, and which DC is appropriate given the player's stated approach to the goal. Or providing such a list to the players.

Interesting to look at in any case, so thanks for posting it.

Quite so. In fact, I would go further to say that in general, I would not advise consulting DC lists of any kind during a game. DCs in general are problematic in that they give many people the wrong idea that the DC is inherent to the task.

The DC actually represents how difficult it is to achieve a task in context. In an adventure, that context is typically duress or some kind of urgency. A wizard who wants to examine a body for signs of magical damage might have to roll against a DC of 10-15 if there's only a minute to look at the body. If they just glimpse the body, it might be a DC of 20. If the party takes the body back to their base for the wizard to examine, however, that should be a DC of 0.

That said, I plan to winnow down the list over the coming days if I can. I do think there is value in knowing what a skill is intended for. It helps DMs make good calls, it helps players design characters to do what they want, and it helps keep them both on the same page.

 

[iserith]

Quite so. In fact, I would go further to say that in general, I would not advise consulting DC lists of any kind during a game. DCs in general are problematic in that they give many people the wrong idea that the DC is inherent to the task.

The DC actually represents how difficult it is to achieve a task in context. In an adventure, that context is typically duress or some kind of urgency. A wizard who wants to examine a body for signs of magical damage might have to roll against a DC of 10-15 if there's only a minute to look at the body. If they just glimpse the body, it might be a DC of 20. If the party takes the body back to their base for the wizard to examine, however, that should be a DC of 0.

Agreed, assuming we're talking about situations that call for a check at all. In many cases, no ability check is needed because the task is impossible, trivially easy, or there's no meaningful consequence for failure.

That said, I plan to winnow down the list over the coming days if I can. I do think there is value in knowing what a skill is intended for. It helps DMs make good calls, it helps players design characters to do what they want, and it helps keep them both on the same page.

I prefer to just do what the rules say in Chapter 7 of the PHB/Basic Rules which lay out what the ability check and skill proficiencies are for: "An Intelligence check comes into play when you need to draw on logic, education, memory, or deductive reasoning." Then, Arcana may apply if the character is trying "to recall lore about spells, magic items, eldritch symbols, magical traditions, the planes of existence, and the inhabitants of those planes."

A line from the DMG is also helpful here (DMG, p. 238): "If the only DCs you ever use are 10, 15, and 20, your game will run just fine."

My strategy is to teach players to just say what they do and hope to accomplish. Then I will ask for an ability check when it's warranted. They can then add a relevant skill proficiency to the roll if their approach lines up with it. And the DC is generally 10, 15, or 20 unless it's a contest.

 

[cbwjm]

What do all of the acronyms stand for? I know PHB, DMG, XGE but I can't figure out the others.

 

[Simonb1]

Most of the other codes are adventure modules, OotW and LLoK are the ones that I do not recognise. Although they could be AL modules?

Simon

 

[Tony Vargas]

Makes me wonder if breaking Spellcraft, and perhaps even a second knowledge ('da Planes?') back out from Arcana wouldn't be a bad idea.

 

[BlivetWidget]

@Tony Vargas It depends on the frequency of different checks in your games, I suppose. Some modules ask for almost 50 Arcana checks, some ask for none, and most ask for about 5.

@Simonb1 and @cbwjm yes, they're the 5e adventure modules. OotW is The Orrery of the Wanderer, LLoK is Lost Laboratory of Kwalish.

@iserith I'm with you for the most part, but I feel like there are two points where we might have differing opinions:

I feel like the PHB description of the Arcana skill is lacking a lot of the intent behind the skill. A strict reading from the PHB would give you no indication that a player could use Arcana to detect and disable magic traps, for instance, to say nothing of the myriad other uses presented by WotC in the adventure modules, such as sensing the aura of a magic item/area/portal or bypassing a magic lock. I'm pretty sure I've read complaints on this board that "Arcana isn't Detect Magic," but the designers of the game clearly believe it's a decent substitute.

I also generally like the "hope to accomplish" strategy, but I feel that it breaks down at some point when it comes to supernatural abilities. The player simply doesn't have the life experiences of a magic user. A new wizard player might not know they have anything to contribute to checking for traps, believing that's the rogue's wheelhouse. Or they might not know to say they want to try to sense magic auras because, there's nothing in the PHB that tells them they can do that.

I guess what I'm saying is: ignore the DCs; I'm really just trying to put together a list of examples of what Arcana can do in practice, to expand on what the PHB says.

 

[Quickleaf]

Most of the other codes are adventure modules, OotW and LLoK are the ones that I do not recognise. Although they could be AL modules?

Simon

LLOK = Lost Laboratory of Kwalish (DMs Guild)

 

[iserith]

I feel like the PHB description of the Arcana skill is lacking a lot of the intent behind the skill. A strict reading from the PHB would give you no indication that a player could use Arcana to detect and disable magic traps, for instance, to say nothing of the myriad other uses presented by WotC in the adventure modules, such as sensing the aura of a magic item/area/portal or bypassing a magic lock. I'm pretty sure I've read complaints on this board that "Arcana isn't Detect Magic," but the designers of the game clearly believe it's a decent substitute.

I also generally like the "hope to accomplish" strategy, but I feel that it breaks down at some point when it comes to supernatural abilities. The player simply doesn't have the life experiences of a magic user. A new wizard player might not know they have anything to contribute to checking for traps, believing that's the rogue's wheelhouse. Or they might not know to say they want to try to sense magic auras because, there's nothing in the PHB that tells them they can do that.

I don't find the PHB entry to be lacking at all. Very simply, if you encounter a magical thing, try to recall what you know about it like how to deal with the magical glyph warding the door. Upon successfully recalling what to do, do that thing with automatic success. As for designers using it for "detect magic," that's just sloppy design and not worth emulating in my view as it is not in line with the rules. It's certainly in line with the rules of D&D 4e though (see D&D 4e Rules Compendium, page 135), but one wonders why it's showing up in a D&D 5e module. Sounds like whoever wrote that was conflating the rules from different games.