Arcana Check Calculator

Arcana is a D&D 5e Intelligence skill for recalling knowledge about spells, magic items, symbols and arcane traditions. When you want to identify a magic effect, translate a runic inscription, or remember whether a certain incantation has a reputation for backfiring, the Dungeon Master calls for an Arcana check. It is one of the classic "lore check" skills that lets a scholarly character shine between combat encounters, and it is often the difference between walking into a glyph ward face-first and spotting it from across the room.

Humanising the check

If your character has spent adventures studying spellbooks, peering at scrolls and asking hard questions of wizards, it should show in the numbers. That is exactly what the Intelligence modifier and the proficiency bonus capture. Modifiers reflect your natural book smarts, while proficiency represents focused training in the Arcana skill itself — and Expertise tells a story of someone who has made arcane theory a genuine specialty, not just a hobby.

The formula

Arcana check = d20 roll + Intelligence modifier + proficiency bonus

• d20 roll — the die, from 1 to 20. This is the element of luck and chaos that keeps even a master sage humble; a natural 1 can still happen to the smartest wizard in the land.
• Intelligence modifier — Arcana is based on Intelligence, which measures memory, reasoning and how well you grasp abstract theories. A high score means your character simply knows things others have to look up.
• Proficiency bonus — only added if proficient in the Arcana skill; Expertise doubles it.

Example

A level 9 wizard (proficiency +4, Intelligence modifier +4, proficient) rolls a 12:

Arcana = 12 + 4 + 4 = 20

That 20 beats most street-level DCs with room to spare and gives the DM a good reason to hand over the finer details of the enchantment they were planning to keep vague.

Reading the total

With Expertise

Wizards can take Expertise (some subclasses, or the feat) to double proficiency:

12 + 4 + (4 × 2) = 24

Now that same roll sails past DC 20 with ease, which becomes important when the check is hard enough that a single missed detail could cost the party dearly.

Comparing Arcana to other knowledge skills

It helps to know when to reach for Arcana and when another skill fits better. Arcana covers magical knowledge; Religion deals with deities, holy symbols and the undead; History covers the world's past events; Nature covers plants, animals and the natural world. Magic-adjacent mysteries (a haunted relic, a cursed object, an ancient ward) often blur the line, so talk to your DM about which skill they will accept — many tables allow multiple skills to get you to the same clue.

A strategy note for players

Because a check is usually rolled once rather than re-rolled, small bonuses matter enormously. A +1 difference can shift a tough DC from a stretch to a comfortable beat. If your party faces a mystery-heavy campaign, an Arcana-proficient wizard or artificer is worth their weight in spell components — and this calculator makes it easy to see exactly what your total will be before the dice ever hit the table.

The DM sets the DC — the number you must meet or beat. A check of 20 is a strong success against most DCs, and the table above is a helpful guide to how much information a given total should unlock.