Spell resistance is a special defensive ability. If the character's spell is being resisted by a creature with spell resistance, the character must make a caster level check (1d20 + caster level) at least equal to the creature's spell resistance rating for the spell to affect that creature.
- The defender's spell resistance rating is like an AC against magical attacks.
The Spell Resistance line and descriptive text of a spell tell the character if spell resistance protects creatures from it. In many cases, SR applies only when a resistant creature is targeted by the spell, not when a resistant creature encounters a spell that is already in place.
The terms "Object" and "Harmless" mean the same thing as for saving throws. A creature with spell resistance must voluntarily drop the resistance in order to receive the effects of a spell noted as Harmless without the caster level check described above.