Intelligence measures mental acuity, accuracy of recall, and the ability to reason.
An Intelligence check comes into play when you need to draw on logic, education, memory, or deductive reasoning. The Arcana, History, Investigation, Nature, and Religion skills reflect aptitude in certain kinds of Intelligence checks.
Arcana. Your Intelligence (Arcana) check measures your ability to recall lore about spells, magic items, eldritch symbols, magical traditions, the planes of existence, and the inhabitants of those planes.
History. Your Intelligence (History) check measures your ability to recall lore about historical events, legendary people, ancient kingdoms, past disputes, recent wars, and lost civilizations.
Investigation. When you look around for clues and make deductions based on those clues, you make an Intelligence (Investigation) check. You might deduce the location of a hidden object, discern from the appearance of a wound what kind of weapon dealt it, or determine the weakest point in a tunnel that could cause it to collapse. Poring through ancient scrolls in search of a hidden fragment of knowledge might also call for an Intelligence (Investigation) check.
Nature. Your Intelligence (Nature) check measures your ability to recall lore about terrain, plants and animals, the weather, and natural cycles.
Religion. Your Intelligence (Religion) check measures your ability to recall lore about deities, rites and prayers, religious hierarchies, holy symbols, and the practices of secret cults.
Other Intelligence Checks. The GM might call for an Intelligence check when you try to accomplish tasks like the following:
- Communicate with a creature without using words
- Estimate the value of a precious item
- Pull together a disguise to pass as a city guard
- Forge a document
- Recall lore about a craft or trade
- Win a game of skill
Wizards use Intelligence as their spellcasting ability, which helps determine the saving throw DCs of spells they cast.