Steady Spellcasting Feat 6
Source Pathfinder Advanced Player's Guide
Confident in your technique, you don't easily lose your concentration when you Cast a Spell. If a reaction would disrupt your spellcasting action, attempt a DC 15 flat. If you succeed, your action isn't disrupted.
Traits
Anything that doesn't list another rarity trait (uncommon, rare, or unique) automatically has the common trait. This rarity indicates that an ability, item, or spell is available to all players who meet the prerequisites for it. A creature of this rarity is generally known and can be summoned with the appropriate summon spell.
BardThis indicates abilities from the bard class.
ClericThis indicates abilities from the cleric class.
DruidThis indicates abilities from the druid class.
OracleThis indicates abilities from the oracle class.
SorcererThis indicates abilities from the sorcerer class.
WitchThis indicates abilities from the witch class.
WizardThis indicates abilities from the wizard class.