Alchemist | Antipaladin | Arcanist | Barbarian | Barbarian (Unchained) | Bard | Bloodrager | Brawler | Cavalier | Cleric | Druid | Fighter | Gunslinger | Hunter | Inquisitor | Investigator | Kineticist | Magus | Medium | Mesmerist | Monk | Monk (Unchained) | Ninja | Occultist | Oracle | Paladin | Psychic | Ranger | Rogue | Rogue (Unchained) | Samurai | Shaman | Shifter | Skald | Slayer | Sorcerer | Spiritualist | Summoner | Summoner (Unchained) | Swashbuckler | Vigilante | Warpriest | Witch | Wizard
Companion | Drake | Eidolon | Eidolon (Unchained) | Familiar | Phantom
Adept | Aristocrat | Commoner | Expert | Warrior

Arcanist Class Details | Exploits | Archetypes

Suffering Knowledge (Su)

Source Advanced Class Guide pg. 14
Strength Greater
The arcanist can learn to cast a spell by suffering from its effects. When the arcanist fails a saving throw against a spell cast by an enemy, as an immediate action she can expend 1 point from her arcane reservoir to temporarily acquire the spell. She can cast the spell using her spell slots as if it was a spell she had prepared that day. The spell must be on the sorcerer/wizard spell list and must be of a level that she can cast. The ability to cast this spell remains for a number of rounds equal to the arcanist’s Charisma modif ier (minimum 1).