Usually a harmful spell allows a target to make a saving throw to avoid some or all of the effect.
The Saving Throw entry in a spell description defines which type of saving throw the spell allows and describes how saving throws against the spell work.
Negates: The spell has no effect on a subject that makes a successful saving throw.
Partial: The spell causes an effect on its subject. A successful saving throw means that some lesser effect occurs.
Half: The spell deals damage, and a successful saving throw halves the damage taken (round down).
None: No saving throw is allowed.
Disbelief: A successful save lets the subject ignore the effect.
(object): The spell can be cast on objects, which receive saving throws only if they are magical or if they are attended (held, worn, grasped, or the like) by a creature resisting the spell, in which case the object uses the creature’s saving throw bonus unless its own bonus is greater. (This notation does not mean that a spell can be cast only on objects. Some spells of this sort can be cast on creatures or objects.) A magic item’s saving throw bonuses are each equal to 2 + one-half the item’s caster level.
(harmless): The spell is usually beneficial, not harmful, but a targeted creature can attempt a saving throw if it desires.
Saving Throw Difficulty Class: A saving throw against your spell has a DC of 10 + the level of the spell + your bonus for the relevant ability (Intelligence for a wizard, Charisma for a sorcerer or bard, or Wisdom for a cleric, druid, paladin, or ranger). A spell’s level can vary depending on your class. Always use the spell level applicable to your class.
Succeeding on a Saving Throw: A creature that successfully saves against a spell that has no obvious physical effects feels a hostile force or a tingle, but cannot deduce the exact nature of the attack. Likewise, if a creature’s saving throw succeeds against a targeted spell you sense that the spell has failed. You do not sense when creatures succeed on saves against effect and area spells.
Automatic Failures and Successes: A natural 1 (the d20 comes up 1) on a saving throw is always a failure, and the spell may cause damage to exposed items (see Items Surviving after a Saving Throw, below). A natural 20 (the d20 comes up 20) is always a success.
Voluntarily Giving up a Saving Throw: A creature can voluntarily forego a saving throw and willingly accept a spell’s result. Even a character with a special resistance to magic can suppress this quality.
Items Surviving after a Saving Throw: Unless the descriptive text for the spell specifies otherwise, all items carried or worn by a creature are assumed to survive a magical attack. If a creature rolls a natural 1 on its saving throw against the effect, however, an exposed item is harmed (if the attack can harm objects). Refer to Table: Items Affected by Magical Attacks. Determine which four objects carried or worn by the creature are most likely to be affected and roll randomly among them. The randomly determined item must make a saving throw against the attack form and take whatever damage the attack deal.
If an item is not carried or worn and is not magical, it does not get a saving throw. It simply is dealt the appropriate damage.
|3rd||Magic helmet, hat, or headband|
|4th||Item in hand (including weapon, wand, or the like)|
|6th||Stowed or sheathed weapon|
|9th||Magic jewelry (including rings)|
(1) In order of most likely to least likely to be affected.