Wild Shape

Animal forms
At levels 2 and 5 a druid may use their 'Wild Shape' feat to change into an animal.
 * You are considered an animal. This renders you immune to spells and abilities that only work on humanoid targets, and Warforged will no longer suffer from the penalty to healing.
 * You have a -2 penalty to Intelligence and Charisma.
 * Animal forms use the the player's main hand weapon for melee attack purposes, including Base Damage, Critical Multiplier, Critical Threat Range, all Enchantments, and Material traits and procs. Original attack stats for wolf/bear are used if you are unarmed.
 * Using a two-handed weapon grants the 1.5 damage from your modifying stat, and Power Attack feat adjustments in animal form as well for its additional bonus.
 * Effects that modify your weapon's base stats work normally, such as changing your primary damage stat.
 * Weapon type feats such as Weapon Focus and Improved Critical apply based on the type of the equipped weapon.
 * At level 3 a druid may choose to take Natural Fighting as a feat choice, which applies only in animal form. This feat may be taken up to 3 times. No other combat style-specific feat bonuses (such as Two Weapon Fighting) apply while in animal form.
 * Stat bonuses, skill bonuses, stunning, etc. apply from both hands.
 * AC and other bonuses from any shield you may be using apply (although you can't shield bash).
 * Ranged and throwing weapons cannot be used.
 * You cannot use wands or scrolls while in animal form.
 * Animal forms increase the cooldown times of your non-animal form spells to 2.5 times their normal length.
 * Animal form special attacks are considered spells, so to use them you must first prepare them in your spell book.

Wolf

 * You gain +15% base attack speed, +3 to attack while flanking, +1d6 sneak attack damage, and +10% to movement speed.
 * Form specific spells: Takedown, Baiting Bite, Harrowing Pack, Howl of Terror

Bear

 * You gain +15% base attack speed, +2 racial bonus to constitution, and +10% AC.
 * Form specific spells: Maul, Roar, Shred, Rising Fury, Tremor

Magical beast forms
At levels 8 and 11 a druid may use their 'Wild Shape' feat to change into a magical beast.

See animal form above.

Winter Wolf

 * You gain a +30% combat style bonus to melee attack speed, +5 to attack while flanking, +2d6 sneak attack damage, and +[10+druid level]% to movement speed.
 * Form specific spells: Takedown, Baiting Bite, Harrowing Pack, Cold Breath, Frostbite, Jaws of Winter, Howl of Terror, Snowslide

Dire Bear

 * You gain +15% base attack speed, +4 racial bonus to constitution, and +15% AC.
 * Form specific spells: Maul, Roar, Shred, Rising Fury, Tremor, Relentless Onslaught, Unstoppable

Elemental forms
At levels 13 and 17 a druid may use their 'Wild Shape' feat to change into an elemental.
 * You are considered an elemental.
 * You gain a +10 racial bonus to your saving throws against magical poisons
 * You have racial immunity to natural poisons, sleep, paralysis and stun, and 100% bonus to fortification.
 * Elemental forms keep their equipped weapons after the transformation.
 * You must prepare your elemental form spells as normal and do not receive additional spell preparation slots for them.

Water Elemental

 * You gain +3 bonus to caster level and max caster level to water and cold spells.
 * Your fire spells get a -3 penalty to caster level and max caster level.
 * You gain a +65 racial bonus to cold absorption, and 15% vulnerability to electricity.
 * You have +20 swim skill.
 * Form specific spells:Elemental Toughness, Freezing Spray, Ice Flowers, Mantle of the Icy Soul

Fire Elemental

 * You can breath indefinitely underwater
 * You gain +3 bonus to caster level and max caster level to fire spells.
 * Your water spells get a -3 penalty to caster level and max caster level.
 * You gain a +65 racial bonus to fire absorption, and 15% vulnerability to cold.
 * Form specific spells: Body of the Sun, Elemental Toughness, Fires of Purity, Anger of the Noonday Sun

Warforged

 * You are considered an animal (or magical beast) or elemental when you change form. If you are a warforged you are no longer considered a living construct. You can now be healed normal by positive energy spells, you become immune to repair spells and rust damage, your healing when you rest is based on the heal skill, and you lose your racial immunities to sleep energy drain, poison,etc. You also lose the benefits of warforged healers friend enhancements.

Monk

 * If you have monk levels, the damage of your animal form matches that of your monk unarmed damage, which means at low levels it will decrease your damage in bear form, but as you progress, the damage will increase as normal for monk.
 * Weapon Focus: Unarmed (granted by Weapon Focus: Bludgeoning) and other effects that improve unarmed attacks also affect the attacks of animal/magical beast forms.
 * Two Weapon Fighting and other combat style feats do not affect your attacks in animal form, irrespective of any levels in monk.
 * Monk stances can be used in animal form, as long as you are centered.
 * The spell Flame Blade will not uncenter you and the blade's strength improves with your caster level. Wisdom bonus to hit and damage does apply in animal form.
 * If you are a monk, and have two non druid (eg kama) weapons equipped, your damage in animal form will revert to the base damage of the animal, instead of the monk Unarmed Strike damage. You will also get no benefit of the magical properties of either weapon. (to work around this, only have one weapon equipped as you shift, then the damage will be calculated properly).
 * Stunning Fist does not work in Druid animal forms, even if handwraps are equipped.

Bard
You cannot swashbuckle in animal form.

Other effects that change your form
Wild shape is not compatible with other effects that change your body. You cannot benefit from two transformations, only the latest applies.
 * Undead forms
 * Celestial Spirit