Metal represents firmness, rigidity, persistence, strength, determination, and electricity. It is commonly represented by gold and silver as its purest forms, though lower magic relating to iron and steel is part of the metal school.
At 1st level, add the following spells to your Wizard spell list at the listed spell level:
Whenever you cast a spell that deals hit point damage, you deal extra damage to creatures made of metal or wearing medium or heavy metal armor. Affected creatures take additional damage equal to 1/2 your Wizard level. This bonus damage is not increased by Empower Spell or similar effects. This bonus only applies once to a spell, not once per missile or ray, and cannot be split between multiple missiles or rays. The damage is of the same type as the spell.
At 20th level, whenever you cast a spell on a creature made of metal or wearing medium or heavy armor, you can roll twice to penetrate the creature’s spell resistance and take the better result.
You gain a +2 armor bonus to your Armor Class for 10 minutes; this bonus increases by +1 for every 5 caster levels (maximum +6 at 20th level). You can use this ability a number of times per day equal to 3 + your Intelligence bonus.
At 8th level, as a swift action, you can cause jagged pieces of metal to explode outward from your body. These shards deal 1d6 points of piercing damage per two Wizard levels (minimum 1d6) to all creatures within a 10-foot-radius burst. A Reflex save halves this damage. In addition, the twisted scraps of metal make the area difficult terrain until your next turn (at which time they disappear). You can use this ability once per day, plus one additional time per day at 13th level and 18th level. At 10th-level, the shrapnel bypasses damage reduction as if it were a magic weapon.
Some philosophers claim that the four-element structure of reality—air, earth, fire, water—is an erroneous belief. These scholars insist there are not four elements, but five: fire, earth, metal, water, and wood. Wizards who subscribe to these beliefs have developed the ability to tap into elemental sources of metal and wood, gaining magical powers normally limited to other kinds of spellcasters.
In some lands, scholars of magic insist that material things consist of five elements, not four: fire, earth, metal, water, and wood. Rather than directly opposing each other, these five elements counter and generate each other in a wheel-like formation: wood overcomes earth, earth overcomes water, water overcomes fire, fire overcomes metal, and metal overcomes wood.
Similar to the four types of elemental wizard schools, some wizards specialize in the schools of magic based on metal or wood. Like a normal arcane school, an elemental school grants a number of school powers and one bonus spell slot of each level the wizard can cast, from 1st on up. This bonus spell slot must be used to prepare a spell from the elemental school’s spell list (see below). Unlike a normal arcane school, each elemental school requires the wizard to select his opposed element as his opposition school—in the case of the five-element system, he must choose the element that overcomes his element as his opposition element (so a metal elementalist must select fire as his opposition school because fire overcomes metal). He does not need to select a second opposition school. He must expend two spell slots to prepare a spell from his opposed elemental school as normal.
Pathfinder Roleplaying Game Ultimate Magic. © 2011, Paizo Publishing, LLC; Authors: Jason Bulmahn, Tim Hitchcock, Colin McComb, Rob McCreary, Jason Nelson, Stephen Radney-MacFarland, Sean K Reynolds, Owen K.C. Stephens, and Russ Taylor.