Spellbooks: A magus must study his spellbook each day to prepare his spells. He cannot prepare any spell not recorded in his spellbook except for read magic, which all magi can prepare from memory. A magus begins play with a spellbook containing all 0-level magus spells plus three 1st-level magus spells of his choice. The magus also selects a number of additional 1st-level magus spells equal to his Intelligence modifier to add to his spellbook. At each new magus level, he gains two new magus spells of any spell level or levels that he can cast (based on his new magus level) for his spellbook. At any time, a magus can also add spells found in other spellbooks to his own (see Arcane Spells).
A magus can learn spells from a wizard's spellbook, just as a wizard can from a magus's spellbook. The spells learned must be on the magus spell list, as normal. An alchemist (see the Alchemist description) can learn formulae from a magus's spellbook, if the spells are also on the alchemist spell list. A magus cannot learn spells from an alchemist.
Arcane Pool (Su): At 1st level, the magus gains a reservoir of mystical arcane energy that he can draw upon to fuel his powers and enhance his weapon. This arcane pool has a number of points: 4
At 1st level, a magus can expend 1 point from his arcane pool as a swift action to grant any weapon he is holding a +1 enhancement bonus for 1 minute. For every four levels beyond 1st, the weapon gains another +1 enhancement bonus, to a maximum of +5 at 17th level. These bonuses can be added to the weapon, stacking with existing weapon enhancement to a maximum of +5. Multiple uses of this ability do not stack with themselves.
At 5th level, these bonuses can be used to add any of the following weapon properties: dancing, flaming, flaming burst, frost, icy burst, keen, shock, shocking burst, speed, or vorpal. Adding these properties consumes an amount of bonus equal to the property's base price modifier (see the Magic Weapon Special Ability Descriptions). These properties are added to any the weapon already has, but duplicates do not stack. If the weapon is not magical, at least a +1 enhancement bonus must be added before any other properties can be added. These bonuses and properties are decided when the arcane pool point is spent and cannot be changed until the next time the magus uses this ability. These bonuses do not function if the weapon is wielded by anyone other than the magus.
A magus can only enhance one weapon in this way at one time. If he uses this ability again, the first use immediately ends.
Cantrips: A magus can prepare a number of cantrips, or 0-level spells, each day, as noted in the table above under “Spells per Day.” These spells are cast like any other spell, but they are not expended when cast and may be used again.
Spell Combat (Ex): At 1st level, a magus learns to cast spells and wield his weapons at the same time. This functions much like two-weapon fighting, but the off-hand weapon is a spell that is being cast. To use this ability, the magus must have one hand free (even if the spell being cast does not have somatic components), while wielding a light or one-handed melee weapon in the other hand. As a full-round action, he can make all of his attacks with his melee weapon at a –2 penalty and can also cast any spell from the magus spell list with a casting time of 1 standard action (any attack roll made as part of this spell also takes this penalty). If he casts this spell defensively, he can decide to take an additional penalty on his attack rolls, up to his Intelligence bonus, and add the same amount as a circumstance bonus on his concentration check. If the check fails, the spell is wasted, but the attacks still take the penalty. A magus can choose to cast the spell first or make the weapon attacks first, but if he has more than one attack, he cannot cast the spell between weapon attacks.
