Paladins devote themselves to three ideals: purity, honour and strength. A paladin’s primary duty is to her deity, and she seeks to bring others to her way of thinking by example — through strength of faith, strength of mind, or, if all else fails, strength of arms. Not that paladins believe in a “convert or die” philosophy — only that those who seek to do evil must be taught the error of their ways. Paragons of devotion, decency and diplomacy, paladins are seen as inspirations to the young — shining examples of what anyone can become with enough hard work, sacrifice and faith.
Paladins worship many different deities. The most common is Iomedae, the ascended goddess of valour and justice. Erastil commands the obedience of a great many holy warriors, particularly those who uphold justice for the common folk. Paladins of Torag are highly sought as military commanders. Adventuring paladins often spread the word of Sarenrae, the goddess of the sun, honesty, healing and redemption — for paladins often seek adventure as a form of penance. Some paladins serve Abadar, Irori or Shelyn, but paladins who serve no specific god are actually more common.
Unlike noble knights, paladins are not always armed with the keenest weapons and clad in the finest armour, although they are always clean and orderly. Slovenly behaviour is a sign of poor discipline and lack of conviction. Most proudly display emblems of their faith and carry their holy symbols in plain sight. Even those who serve mortal authorities work their holy symbols into their badges of office. Scions of evil who hunt paladins often make trophies of their victims’ gear.
Favoured Regions: Paladins are a rare breed, as few people volunteer for a life of hardship and peril in the service of their religion. Paladins dwell in enclaves here and there, separate from the temptations of society. There they train, pray and sometimes simply fight for their lives against the forces of evil, as in the Star Keep in Mendev, where fewer than a hundred paladins stand against the Worldwound’s demonic hordes.
Vigil, in Lastwall, hosts perhaps the largest concentration of paladins, due to the massive training facilities in the Holy Citadel of Light, where the young knights practice the arts of war battling hordes of orcs from Belkzen. Andoran also provides training grounds for holy warriors, many using their faith to underscore political ideology as members of that nation’s famous (or infamous) Eagle Knights. More formal schools exist in Absalom, Brevoy, Osirion and Taldor, and countless mentors train apprentices all over Golarion.
Light of Purity (Su): Paladins trained in the Holy Citadel of Light focus specifically on the destruction of undead and are often charged with cleansing the land around Gallowspire of its necrotic taint. These paladins gain the following special ability, which replaces the remove disease ability gained at 6th level and all increases in that ability.
Starting at 6th level, a paladin with this ability can emit a radiance of blinding light once per week. This light acts like a daylight spell, save that it only lasts for 1 round per level of the paladin. In addition, any undead within 30 feet of the paladin emitting this light takes 1d6 points of damage per round for every two levels the paladin has attained. A Fortitude save (DC 10 + ½ the paladin’s level + the paladin’s Charisma modifier) halves this damage. A paladin may use the light of purity one additional time per week for every three additional levels he has attained, to a maximum of five times at 18th level.
Source: Pathfinder Chronicles: Campaign Setting (Page 47)