Magic resistance

Magic resistance (MR) is a – sometimes natural – status effect applied to a creature which determines the chance that a hostile spell cast on the creature will outright fail and spell effects not be applied. Friendly spells and potions are not affected by MR.
Even if the MR check fails, a saving throw may still prevent the spell. For example, a hostile wizard casts Charm Person on Gorion's Ward and she fails the Magic Resistance check. A save vs. spell check is now rolled and if she succeeds, she will not be charmed.
Against spells which create multiple projectiles (like Magic Missile or Flame Arrow), MR is checked individually for each projectile.
Some races, such as the drow, have inherent magic resistance. Many items grant a certain, often accumulative magic resistance to their wearer or consumer.
Enemy magic resistance can be lowered with the following spells: Lower Resistance, Pierce Magic, Pierce Shield, Magic Resistance (if spell output determined by formula [caster level]*2% is lower than creature's natural magic resistance). Those themselves cannot be stopped by MR.
Some spells bypass magic resistance. These include Bolt of Glory, Dragon's Breath, Fire Storm, Implosion, Shocking Grasp, Imprisonment, Energy Drain, Contagion, Deafness, Teleport Field, False Dawn (on undead), Blade Barrier and Globe of Blades, Fireshield and Aura of Flaming Death, the damage of Earthquake, Chain Lightning when cast by an Avenger, Lower Resistance and other spells that target MR, Breach, spells that attack/strip magical defenses, spells like True Sight that dispel invisibility / illusions, spells that summon weapons or throwable projectiles like Melf's Minute Meteors, Sol's Searing Orb or Shillelagh, the unconsciousness effect of Comet, the death effect of Slay Living, and Time Stop. In the non EE games, Sunfire and Glitterdust also bypass MR. See also :Category:Bypass Magic resistance. It is still possible to become immune to some of these spells, either by using an appropriate spell protection spell or by using the rare Protection From Magic scrolls. Immunities to certain spell levels (Potion of Magic Blocking, innate immunities of Liches and Rakshasas) also completely block spells, even those that bypass MR.
Magic resistance also applies to some effects tied to innate abilities or items, but not to others; this differs from case to case. For example, Jester Song ignores MR, but a Blackguard's Aura of Despair is blocked by MR. An item can also have different applications for multiple effects, e.g. Celestial Fury blindness bypasses MR, but its lightning strike does not.
Magic resistance can be above 100%, up to 127%. Resistance over 100% provides no direct benefits, but is an additional layer of protection against Lower Resistance.
==Improving magic resistance==
===Permanent bonuses===
* The "good path" in the Test of Selfishness increases the magic resistance of Gorion's Ward by 10%.
* The Machine of Lum the Mad allows one party member to permanently raise their magic resistance by 5% if using the right combination.
* Monks and wizard slayers gain level-dependent bonuses.
* The companions Viconia and Baeloth have innately a magic resistance of at least 50% since they are drow.
===Equipment===
==== Armor ====
*Human Flesh +5
*Silver Dragon Scale
*Enkidu's Full Plate
*Drow Elven Chain
*Big Metal Unit
*Corwin's Armor
==== Robes ====
*Robe of Vecna
*Robe of the Evil Archmagi
*Robe of the Good Archmagi
*Robe of the Neutral Archmagi
*Robe of Netheril
==== Weapons ====
*Carsomyr
*Purifier
*Hindo's Doom +4
*Sword of Balduran 
*Flame of the North
*Flail of Ages +5
*Gram the Sword of Grief (upgraded)
*The Soulherder's Staff
*Aster's Edge
==== Amulets ====
*Amulet of Seldarine
*Kaligun's Amulet of Magic Resistance
*Amulet of Power
*Amulet of 5% Magic Resistance
==== Rings ====
*Ring of Gaxx
*Holy Symbol of Baervan Wildwanderer
*Holy Symbol of Talos
*Holy Symbol of Helm
*Holy Symbol of Lathander
*Holy Symbol of Shar
*Holy Symbol of Tempus
*Holy Symbol of Tyr
==== Shields ====
*Shield of the Lost
*Shield of Fyrus Khal
==== Boots ====
*Star-Strewn Boots
==== Cloaks ====
*Cloak of Balduran
===Temporary bonuses===
==== Potions====
*Potion of Magic Protection (+50%)
==== Spells ====
*Magic Resistance (spell)
==== Abilities ====
*Enhanced Bard Song
*Resist Magic (set to 50%)
Shapeshift
* Shapeshift: Werewolf (+40%)
* Slayer Form (+40%)
* Mustard Jelly from Polymorph Self (125%)
* Iron Golem from Shapechange (100%)
==Magic Damage Resistance (MDR)==
Magic resistance is different from resistance to magical damage: magic(al) damage resistance reduces (positive) or amplifies (negative) the damage a creature would take if a spell dealing magical damage gets through the former and is applied after any reduction from a saving throw (if one applies). Technically, this applies to spell abilities and item effects with effect opcode 12 (DAMAGE). The damage type of the effect must be set to 64 (MAGICAL). 
For example, let's say a character with 50% magic resistance is hit by a Skull Trap. If the MR check succeeds, no damage will be taken. If the MR check fails, a saving throw is performed to determine whether full or half damage is to be applied, and finally Magic Damage Resistance is applied. If MDR is negative more damage is applied than what's left after the saving throw.
Magic Damage Resistance has a hard cap of 127 in either direction. A Magic Damage Resistance over 100% means the character is healed when taking magical damage.
Category:Resistances by type