Base Specialisations
Alchemist – skilled with concoctions, remedies, runes and crafting basic magic items
Augur – divining, dispel and time spells
Evoker – elemental damage spells, aoe and elemental summoning
Mesmer – fade, illusion and mind control spells
Psion – telekinesis, teleport and haste and slow
Summoner – a choice of either undead or demonic conjuration, pets and debuffs

Cross Class Specilaisations
Battle Mage – an Evoker’s explosive power with a melee fighter’s mettle
Commander – combines the aegis spells of an Evoker with an Archer’s battle command
Corrupted Master – the unholy power of the Necro with the bodily control of the Monk
Death Knight – the powers of the Necromancer combined with the unholy Knight
Enchanter – the research of the Alchemist combined with the power and craft of a full mage
Golemancer – craft golems and gargoyles and discover the power of the elements
Mentat – Psion telekinesis with a Warrior or Monk melee skills, cannot use armour
Oracle – an Augur’s insight with a Priests divine power, influenced by Lunar phases
Shadow Master – combines Rogue skills with Mesmer spells, the master of stealth
Unholy Blight – an unseelie Priests abilities combined with summoning undead

For Alchemist and Unholy Blight Specialisation go to Priest list, for Battle Mage, Death Knight and Mentat Specialisation go to Warrior List, for Commander Specialisation go to Archer list)

Other:
Lich – gain immortal life and power at the cost of your heart, cohabiting with other essence
Demon – make the full transformation to a greater demon entity, lose all mortal concern

For all of the Base Specialisations the choice is simple: stay within the first, primary chosen class without any cross-class abilities and gain the choice of beginning to add the Level 4 Spells to the Mages Repertoire (at level 60). Any cross-class abilities will need to be unlearned to gain this privilege, other than natural racial bonuses.