All of the following are class features of the havoc mage.

Weapon and Armor Proficiency: Havoc mages gain no proficiency with any weapon or armor.

Spells per Day: At 2nd, 4th, and 5th level, a havoc mage gains new spells per day as if he had also gained a level in an arcane spellcasting class he belonged to before adding the prestige class. He does not, however, gain all the benefits a character of that class would have gained (metamagic or item creation feats, and so on), except for an increased effective level of spellcasting. If a character had more than one arcane spellcasting class before becoming a havoc mage, he must decide to which class he adds the new level for purposes of determining spells per day.

Battlecast (Ex): A havoc mage gains the ability to cast spells of a certain level or lower while making a weapon attack. He may take a full-round action to attack and cast a spell. The spell must be an arcane spell he knows of 2nd level or lower with a casting time of 1 standard action or less. When using his battle-cast ability, a havoc mage may cast spells requiring somatic components even if he has no free hands. Using battle cast does not provoke attacks of opportunity. At 3rd level and higher, a havoc mage can battlecast a spell of 4th level or lower. At 5th level, a havoc mage can battlecast a spell of 8th level or lower. The battlecast ability does not grant a havoc mage any relief from the arcane spell failure chance imparted by armor.