Shapeshifter

Shapeshifters in Thedas
Rumors speak of barbarians that hold secrets of transforming the body into the form of animals. The Circle of Magi denies such stories. But this rare art survives in the forgotten corners of Thedas. While the Circle of Magi would prefer that it be so, theirs is not the only tradition of magic in Thedas. Prior to the Circle’s formation, magic was either practiced by the Magisters of the Tevinter Imperium or in remote areas, knowledge handed down from one generation of practitioners to the next. “hedge mages”, as Enchanters of the Circle refer to them, or “witches” as legend would name them, do not always employ forbidden magic. Quite often their talents lie in the creation of charms, the use of curses and the ability to change their own forms.

It is this last talent that has, over the centuries, been incorporated back into the Circle. Said to have been first introduced by hedge mages that joined the Circle (perhaps by force), the path of the Shapeshifter is one that crosses the boundary between mage and warrior. Some mages see it as a form of self-mastery, while others use it as a method of survival, a physical bag of tricks that enable the mage to be unpredictable in battle.

Shapeshifters must master one form at a time, the most common ones being those that are found in the Fereldan wilds. The mighty bear is popular as are wildcats, spiders, and even birds. Legend tells of mages who mastered even more fantastical and deadly forms. To a skilled Shapeshifter, no door is impassable, no fight is unwinnable, and no terrain inhospitable, as long as they know a shape that can meet the task at hand.

Unlocking
Morrigan will teach you if your approval is neutral, less than 30. However, she will not teach you at all if her approval is over 30.

Alternatively you can buy the specialization as a Manual from Varathorn in the Dalish Camp at the Brecilian Outskirts for around 12 Gold.

The sloth demon in the Circle of Magi opening story can also teach shapeshifting to your companion, but this does NOT unlock the specialization.

Notable Shapeshifters

 * Morrigan
 * Flemeth

Shapeshifting Mechanics
When the caster assumes a new form they also take on new skills, many of which depend on the primary attributes of Warriors or Rogues. Fortunately, Strength, Dexterity, Constitution are boosted substantially by the mage's base spellpower. Attack (see the notes section below), defense, armor, armor penetration, missile deflection and HP are also improved.

Notes (please read entire article first before editing, to prevent reposting information)

 * Casters generally do not have access to potions and other items while in an alternative form.
 * Forms are generally faster than most humanoids.
 * Form statistics appear to improve around every 10 Spellpower.
 * The mage gains several resistances and immunities while shapeshifted, including increased nature resistance, knockdown immunity and grab immunity.


 * Poison-making (poison-coating, to be used before shifting) and Combat Training (attack, defense and damage bonuses) work normally while shapeshifted.
 * Sustained spells are automatically deactivated when changing forms.
 * Changing back to original form happens instantly, and can be done while the game is paused.
 * The forms are all generally unsuited for sustained combat, unless a few compromises are made - one can spend several points on the strength attribute to improve damage and allow more powerful armor to be worn, and then rely on an ally for healing. With massive armor and a dedicated healer, a high level mage in bear form can hold its own against drakes and revenants on nightmare difficulty.
 * All forms greatly improve the mage's physical resistance, even Spider Form. Shapeshifting is one of the few ways mages can increase their physical resistance without further adding points in the strength or constitution attributes.
 * Armor ratings for the spider and bear forms are based on the mage's equipped armor, and are subject to a bonus determined by (base?) spellpower. For Bear Form, the bonus is comparable to that granted by the Rock Armor spell.
 * Spider form has significantly higher attack speed than Bear form, but lower armor and slightly reduced damage.
 * Damage and armor penetration are both based on the mage's weapon. If a mage staff had been equipped prior to shifting, armor penetration can be very high - around mid-40's for the Staff of the Magister Lords. Although the inventory screen reports a higher damage if a powerful two handed weapon is equipped, the staff's significantly higher armor penetration will often offset this. Additionally mage staffs never miss, and the shapeshifted forms seem to stick to this convention. This renders the (unreported) attack score obsolete.


 * Increasing strength will have a larger impact on damage than increasing magic, and also allows more powerful armor to be equipped. Doing so will affect other form bonuses, however, like dexterity, constitution and the Flying Swam's tick damage, and will also decrease the effectiveness of the mage's spells while in human form.
 * The defense score while shifted appears to be completely unrelated to dexterity but is increased by spellpower.
 * Equipping dual weapons will result in left and right hand damage scores being reported when shifted, although the attack animation remains the same.
 * Increasing the mage's constitution attribute will have no impact on the amount of health points the mage has while in spider or bear form. Equipping gear that increases constitution does, however, so one could consider equipping items like Lifegiver and Reaper's Vestments.
 * The extra bonuses granted by the forms are only affected by the mage's base spellpower (+staff?).

Strategies

 * Second specialization
 * Arcane Warrior: Most Arcane Warriors use lots of sustained spells. Since shifting automatically deactivates these, both specializations generally do not work well together.
 * Blood Mage: The Blood Mage skills usually work well with the Shapeshifter's, especially when the mage's forms are already spent.
 * Spirit Healer: Depending on the Spirit Healer's role in the party (dedicated healer or support healer), this specialization may or may not work well with Shapeshifter.


 * Form strategies
 * Spider Form is useful for hit-and-run tactics: snare opponents with Web and leave them to suffer in Poison Spit, or lure them away from their comrades and into an ambush.
 * Bear Form is useful for blocking doorways and providing melee combat support. Its Slam ability can be used to shatter frozen or petrified opponents. The bear's high physical resistance can be further increased with items, allowing it to wade through spells like Earthquake in search of a target.
 * Bear Form's Overwhelm ability is effective against enemy mages, who possess high mental resistances. It can incapacitate and in many cases kill enemy mages all by itself. Some believe it very satisfying to watch an enemy mage be noisily consumed by a large bear.
 * The Flying Swarm's damage-over-time attack does not harm allies and is capable of doing higher tick damage than most damage over time spells.


 * Mage strategies
 * There are generally two types of Shapeshifter builds. The first one focuses on casting primal spells and nuking, and using up its skills to control the battlefield before using any of the Shapeshifting skills. The second focuses on the Shapeshifter forms and spending a longer amount of time shapeshifted, and trying to make the most out of each form's abilities while wearing heavier armor. According to reports, both work just as well.
 * Spider Form and the Flying Swarm rely on dealing nature damage, to which certain creatures are immune (eg, undead and constructs). It might be wise to pick spells which do alternative types of damage.
 * Some forms are effective at "kiting" enemies while party members attack with ranged weapons.
 * The primal spells are the most ideal for the Shapeshifter, consisting of freezing/petrifying spells, cast-and-forget spells, very few sustained spells and more than its share of damage spells. Indeed, a Shapeshifter should consider taking the bulk of his/her spells from the primal spells.
 * Two simple tips to make Shapeshifter work:
 * Fireball->Earthquake->Blizzard->Chain Lightning->Inferno->Shapeshift:Spider. Web + Poison Spit enemies who try to escape the AoE and Overwhelm those who succeed.
 * Fireball->Earthquake->Chain Lightning->Shapeshift:Bear/Flying Swarm and +physical resistance items. Alistair can join in the fun with Shield Wall + Shield Expertise. Sten and Oghren can help if their physical resistances are high enough, just give them weapons with +physical resistance runes and their high strength and constitution attributes take care of the rest. Have everyone else nuke or use ranged weapons.

Reference
Dragon Age: Origins - PRIMA Official Strategy Guide