Magus Spellcasting

You study spells so you can combine them with your attacks or solve problems that strength of arms alone can't handle. You are a spellcaster, and you can cast spells of the arcane tradition using the Cast a Spell activity. As a magus, when you cast spells, you might draw sigils with your weapon or a free hand and shout magical words of power as battle cries.

At 1st level, you can prepare one 1st-rank spell and five cantrips each morning from the spells in your spellbook (see below). Prepared spells remain available to you until you cast them or until you prepare your spells again. The number of spells you can prepare is called your spell slots.

As you increase in level as a magus, the number of spells you can prepare each day increases, as does the highest rank of spell you can cast, as shown in the table.

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). Your spell attack modifier and spell DC are calculated using your Intelligence 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. Many spells have specific improvements when they are heightened to certain ranks

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 always automatically heightened to half your level rounded up—this is usually equal to the highest rank of magus spell slot you have. For example, as a 1st-level magus, your cantrips are 1st-rank spells, and as a 5th-level magus, your cantrips are 3rd-rank spells.

Spellbook

Every arcane spell has a written version, which you record in your personalized book of spells. You start with a spellbook worth 10 sp or less, which you receive for free and must study each day to prepare your spells. Your spellbook's form and name are up to you. It might be anything from a sturdy book with a secure latch entitled Theses on the Stratagems of Supernatural Warfare to a tattered collection of training pamphlets with your name scrawled on the cover.

The spellbook contains your choice of eight arcane cantrips and five 1st-rank arcane spells. You choose these from the common spells on the arcane spell list or from other arcane spells you gain access to.

Each time you gain a level, you add two arcane spells to your spellbook, of any spell rank for which you have spell slots, chosen from common spells of your tradition or others you gain access to. You can also add spells to your spellbook with the Learn a Spell activity.

If you have a spellbook from multiple sources (such as being a magus with the Wizard Dedication feat), you can use the same spellbook for all your spells.