Requirements
Alignment: Any nongood.
Race: Human from Thay.
Spell casting: Ability to cast 3rd level arcane spells.
Skills: Spellcraft 8 ranks.
Feats: Tattoo Focus and a total of three metamagic feats or item creation feats.

Class Skills
Alchemy (Int), Concentration (Con), Craft (Int), Innuendo (Wis), Intimidate (Cha), Knowledge (all skills taken individually) (Int), Profession (Wis), Scry (Int), and Spellcraft (Int).
Skill Points at Each Level: 2 + Int modifier

Class Features
Weapon & Armor Proficiencies: Red Wizards gain no proficiency in any weapon or armor.
Spells per Day: A Red Wizard's training focuses on arcane spells.  Thus, when a new Red Wizard level is gained, the character gains new spells as if she also gained a level in whatever arcane spell casting class she belonged to before he added the prestige class.
Enhanced Specialization:  Upon becoming a Red Wizard, the character increases his devotion to his wizard school of specialization.  In exchange for this, the Red Wizard must sacrifice study in one or more schools.  The Red Wizard must choose an additional prohibited school or schools using the normal rules.  He can never again learn spells from those prohibited schools.  He can not choose the same prohibited schools he chose as a 1st level wizard.  He can still use the prohibited spells he knew prior to becoming a Red Wizard, including using items that are activated by spell completion or spell trigger.
Specialist Defence: Add this value to the Red Wizard's saving throws against spells from his specialist school.
Spell Power: For spells involving the Red Wizard's specialist school, add this value to the DC for saving throws and to caster level checks to overcome spell resistance.  This ability stacks with other effects that affect spells from the Red Wizard's specialist school.
Bonus Feat: The red Wizard can choose an item creation feat, metamagic feat, or Spell Mastery.
Circle Leader: The Red Wizard gains the ability to become a circle leader, who is the focus for Red Wizard circle magic.
Scribe Tattoo: The Red Wizard gains the ability to place the Thayan wizards' magic taboos upon willing and qualified novices, giving them the Tattoo Focus feat and inducting them into the circle.
Great Circle Leader: The Red Wizard can be the center of a great circle, which can have up to nine assistants instead of the usual five.