Oracle Spellcasting
You have an unfiltered connection to the great powers of the universe and the planes beyond, and you can let this power spill forth in the form of divine magic. You are a spellcaster, and you can cast spells of the divine tradition using the Cast a Spell activity. As an oracle, when you cast spells, your incantations may spill from your lips rapidly as you speak in tongues or intone in a voice not quite your own, and your gestures might be wild and unrestrained as religious ecstasy briefly touches your mind.
Each day, you can cast up to three 1st-rank spells. You must know spells to cast them, and you learn them via the spell repertoire class feature. The number of spells you can cast each day is called your spell slots.
As you increase in level as an oracle, your number of spells per day increases, as does the highest rank of spells you can cast, as shown on the Oracle Spells per Day table (shown below).
Some of your spells require you to attempt a spell attack to see how effective they are, or have your enemies roll against your spell DC (typically by attempting a saving throw). Since your key attribute is Charisma, your spell attack modifiers and spell DCs use your Charisma modifier.
Heightening Spells
When you get spell slots of 2nd rank and higher, you can fill those slots with stronger versions of lower-rank spells. This increases the spell's rank, heightening it to match the spell slot. You must have a spell in your spell repertoire at the rank you want to cast in order to heighten it to that rank. Many spells have specific improvements when they are heightened to certain ranks. The signature spells class feature lets you heighten certain spells freely.
Cantrips
Some of your spells are cantrips. A cantrip is a special type of spell that doesn't use spell slots. You can cast a cantrip at will, any number of times per day. A cantrip is automatically heightened to half your level rounded up—this is usually equal to the highest rank of oracle spell slot you have. For example, as a 1st-level oracle, your cantrips are 1st-rank spells, and as a 5th-level oracle, your cantrips are 3rd-rank spells.