Dodge bonus

Overview
The dodge mechanic works as a miss chance - a simple percentile chance to completely avoid physical attacks. You will see a "Dodge" hover over your character anytime it helps you dodge an attack.

Dodge chance mechanic
This check is done independent of the miss chance resulting from Armor Class and other measures of not getting hit, such as Concealment or Incorporeality. The dodge chance is capped by the Maximum dexterity bonus of the armor worn, and cannot exceed 25%. There are some abilities, like Uncanny Dodge, (see below) which exceptionally allow to exceed this cap. Dodge bonuses from spells, enhancements, EDs, items, and feats stack.

As of Update 19, dodge bonuses on items no longer stack, only the best applies.

Maximum Dodge bonus
The normal Dodge bonus cap is 25%, up to the Maximum dexterity bonus of your armor worn. These are ways to increase (or decrease) the maximum amount of dodge bonus that you can get.

Class Enhancements

 * Bard
 * Swashbuckler
 * Roll with the Punches (Core, Lv 18): +5 Insight Bonus to Character Dodge Cap.
 * Fighter
 * Kensei
 * Ascetic Training (Tier 2, Multi-selector): Agility: +1/+2/+3 to dodge cap, Concentration, Reflex Saves. NOTE: Does not stack with Ninja Spy(Mnk): Agility!
 * Improved Mobility (Tier 3): +1/+2/+3 Dodge cap and Maximum Dexterity bonus while wearing light or no armor. -1/-2/-3 Armor Check Penalty in light armor. NOTE: Does not stack with Tempest (Rgr): Improved Mobility!
 * Monk
 * Ninja Spy
 * Agility: +1/+2/+3 Maximum Dodge bonus, Concentration and Reflex Saves.
 * Shintao
 * Meditation of War (Tier 5, Multi-selector): Earth Stance: This actually gives you a penalty of -5% Dodge Cap. You also gain +10 Insight bonus to Physical Resistance and +3% Insight bonus to Maximum Hit Points.
 * Meditation of War (Tier 5, Multi-selector): Water Stance: +5 Insight bonus to Maximum Dodge Bonus. You deal 10% less damage with attacks.
 * Ranger
 * Tempest
 * Improved mobility (Tier 3): +1/+2/+3 dodge cap while wearing light or no armor. -1/-2/-3 armor check penalty in light armor.
 * Rogue
 * Assassin
 * Light Armor Mastery (Tier 5): You gain 1/2/3 to Maximum Dodge. While wearing light armor, gain 2/4/6 to the Maximum Dexterity Bonus of your armor, -2/4/6 armor check penalty, and gain 2/4/6 Physical Resistance Rating.
 * Measure the Foe (Tier 5): Gain +6 Melee Power, +2 Dodge, +2 Maximum Dodge, +1 to hit and +1 to the DC's of your Assassinate abilities for every 4/2/1 seconds you remain stealthed. This effect stacks up to five times, and lasts 10 seconds after you come out of stealth.
 * Thief-Acrobat
 * Tumbler (Core, Lv 6): You can pass through enemies when you tumble. +2 maximum dodge.
 * Kip Up (Core, Lv 12): You are immune to most knockdown effects and slippery surfaces. +2 maximum dodge.
 * Cartwheel Charge (Core, Lv 18): After tumbling, you gain a +2 Morale bonus to Strength and Dexterity for 12 seconds. +2 maximum dodge. +20% Doublestrike with quarterstaff.
 * Spinning Staff Wall (Tier 5): While wearing cloth or light armor, gain +5% Dodge, +5 maximum dodge, and +5 Maximum Dexterity Bonus with Light Armor.

Racial Enhancements

 * Halfling
 * Nimble Reaction (Tier 2): +1/+2/+3 Maximum Dodge Bonus and Armor Maximum Dexterity Bonus (cap).

Guild Enhancements

 * Fencing Master: +2% Guild Bonus to Maximum Dodge

Dodge bonus to Armor Class
Previous to Update 14, Dodge used to be considered a bonus type, generally applying to armor class and sometimes reflex saves. In some very rare areas where the devs forgot to update the bonus types, there are still a few abilities/items that display as dodge bonuses to armor class in the breakdown, but officially the system has been discontinued, so they should be considered bugs.

Examples are:
 * Eldritch Shield Ritual and Eldritch Armor Ritual (Technically should count as bonuses types equal to their name per a dev post)
 * Favored Defense I to III +1-3 (Ranger only, vs. favored enemies)
 * Fighter's Mobility I to II +1-2 (fighter only, only while tumbling; requires Mobility feat)

Feats

 * Dodge: +3%
 * Spring Attack: +2%
 * Mobility: feat/item + 2% (also increases Maximum dexterity bonus by 2)
 * Uncanny Dodge and Improved Uncanny Dodge grant + 1% at Levels 4, 6, 8, 12, 16, and 20 of Rogue or Barbarian, respectively. The bonuses from Uncanny Dodge and Improved Uncanny Dodge do not stack with one another.
 * Uncanny Dodge provides also a clicky with temporary +25%, which ignores Dodge cap.
 * Improved Uncanny Dodge provides also a clicky with temporary +50%, which ignores Dodge cap.
 * Inspire Heroics +4% (level 15 bard buff)
 * Flurry of Blows, when centered: +2%, +4% and +6% at monk levels 1, 2 and 4, respectively.
 * Combat Archery passive: 2% if wielding a ranged weapon.

Monk stances

 * Lesser Ocean Stance: +1%
 * Ocean Stance: +2%
 * Greater Ocean Stance: +3%
 * Ultimate Ocean Stance: +4%

Epic Destinies

 * Meld Into Darkness, active: +100% for up to 12 seconds. (Shadowdancer)
 * Untouchable, passive: +1% extra dodge for each Shadow Charge held (Shadowdancer)
 * Echoes of the Ancestors: Martial: Grandmaster of Flowers: passive, stance, 2% (Fatesinger)
 * Echoes of the Ancestors: Primal (ranged version), passive: 1% (Fatesinger) (?)
 * Perfect Balance, passive: 1% per rank, 3 ranks (Grandmaster of Flowers)
 * Walking with Waves, passive: 1% per rank, 3 ranks (Grandmaster of Flowers)
 * A Scattering of Petals, active: for 12 seconds: +25% (Grandmaster of Flowers)
 * Master's blitz, active: 10 seconds + can be prolonged by killing monsters: +50%, does currently not exceed the dodge cap (bugged). (Legendary Dreadnought)
 * Unearthly reaction, passive: 1% per rank, 3 ranks (Magister)
 * In the weeds, passive: 1% per rank, 3 ranks (Shiradi Champion)
 * In the weeds, passive, when standing still: additional 1% per rank, 3 ranks (Shiradi Champion)

Legendary Feats

 * Scion of the Plane of Air: 4% Dodge, 4 to Dodge cap (maximum Dodge)
 * Scion of the Astral Plane: 4% Dodge, 4 to Dodge cap (maximum Dodge)
 * Scion of Limbo: 20% Dodge (random cycle)

Items

 * Named items: up to 12%
 * Random loot:
 * Dodge suffix (+1 to +6 on heroic accessories/clothing, more on epic)
 * Wariness 2%, Alertness 6%, Omniscience 8% (legacy suffix on armor/headgear/rings)
 * Cannith Crafting: 2 / 4%

Class Enhancements

 * Artificer
 * Arcanotechnician
 * Master Defender (Tier 5): Your Iron Defender provides you 1%/2%/3% Dodge and he gains +2/+4/+6 Strength, Dexterity and Constitution.
 * Barbarian
 * Occult Slayer
 * Uncanny Dodger (Tier 1): +1%/+2%/+3% Dodge.
 * Bard
 * Swashbuckler
 * Confidence (Core, Lv 1): +1% Dodge, +1 Reflex Save, and +1 to the Max Dex Bonus of your Armor per Swashbuckler Core Ability you have.
 * Uncanny Dodge (Core, Lv 6): No dodge bonus, but you gain the Uncanny Dodge feat. You also gain 1% Doublestrike, 1% Doubleshot, and +1 Attack Damage while Swashbuckling.
 * On Your Toes (Tier 1): +1%/2%/3% Dodge.
 * Swashbuckling Style (Tier 3, Multi-selector): Skirmisher: While Swashbuckling with a Buckler in your off hand you gain 10% Dodge, and you may use a Buckler and still benefit from the Single Weapon Fighting line of feats.
 * Druid
 * Nature's Warrior
 * Flight (Tier 2): Use Wild Empathy to gain +10% Dodge for [12/24/36] seconds.
 * Improved Dodge (Tier 3): +1/+2/+3 Dodge while in any Bear or Wolf form.
 * Fighter
 * Kensei
 * Reed In The Wind (Tier 1): Makes an attack with +1[W] damage. If you successfully damage your target you gain a +3%/6%/9% Insight bonus to Dodge for 6 seconds.
 * Improved Dodge (Tier 2): +1%/+2%/+3% Dodge when wearing light or no armor. NOTE: Does not stack with Tempest(Rgr): Improved Dodge!
 * Monk
 * Ninja Spy
 * Acrobatic (Tier 1): +1/+2/+3 Balance, Jump, and Tumble. +1%/+2%/+3% Dodge. BUG: Actual Dodge Bonus is +1%/+2%/+2%!
 * Shintao
 * Reed in the Wind (Tier 1): Makes an attack with +1[W] damage. If you successfully damage your target you gain a +3%/+6%/+9% Insight bonus to Dodge for 6 seconds.
 * Ranger
 * Tempest
 * Improved Dodge (Tier 2): +1%/+2%/+3% dodge when wearing light or no armor.
 * Elaborate Parry (Tier 4): Attacks an opponent. For the next 5/10/15 seconds, each time you damage an opponent you gain +2% dodge for 5 seconds. This effect can stack up to 15 times.
 * Rogue
 * Assassin
 * Nimbleness (Core, Lv12): On Sneak Attack: Up to once every 2 seconds, you gain 1% dodge for 6 seconds. This effect can stack up to 10 times.
 * Thief-Acrobat
 * Shadow Dodge (Tier 3): Toggle: +1%/2%/3% Dodge, +1/+2/+3 Dexterity, -10%/-20%/-30% Fortification. (Sometimes after a relog, you will have to toggle off and on to truly activate).
 * Sorcerer
 * Air Savant
 * Elemental Apotheosis: Air (Core, Lv 20): +3 dodge plus bunch of other really cool stuff.
 * Acrobatic (Tier 1): Rank 3 gives 1% dodge bonus.
 * Wizard
 * Pale Master
 * Bone Armor (Tier 2): While under the effect of Shroud of the Wraith, you gain 1%/2%/3% Dodge.

Racial Enhancements

 * Drow
 * Ambidexterity (Tier 2): Rank 2 gives 1% dodge bonus.
 * Improved Dodge (Tier 3): +1%/+2%/+3% Dodge when wearing light or no armor.
 * Elf
 * Skill (Tier 4): +3% dodge, +3% Doubleshot, +3% Doublestrike, and bypass 3% dodge.
 * Halfling
 * Heroic Companion (Tier 2): Action Boost: Grants an ally 0/+2%/+4% Dodge, +0.25/+0.5/+1[W], +2/+4/+6 to hit and saving throws, and 0/0/+10 Physical Resistance Rating.
 * Improved Dodge (Tier 3): +1%/+2%/+3% Dodge when wearing light or no armor.
 * Halfling Agility (Tier 4): Up to once per second when you are hit, you gain 1% dodge until you are missed. This effect can stack up to 5 times.
 * Human
 * Fighting Style (Tier 2, Multi-selector): Ambidexterity: Rank 2 gives 1% dodge bonus.
 * Morninglord
 * Skill (Tier 4): +3% dodge, +3% Doubleshot, +3% Doublestrike, and bypass 3% dodge.
 * Purple Dragon Knight
 * Fighting Style (Tier 2, Multi-selector): Ambidexterity: Rank 2 gives 1% dodge bonus.
 * Shadar-kai
 * Improved Dodge (Tier 3): +1%/+2%/+3% Dodge when wearing light or no armor.

Dodge stacking
The Dodge bonus always stacks, except the ones you get from items. As of update 19, only the highest item based Dodge bonus will apply.

Prior to update 19, there were some issues with stacking sometimes. Depending on the order you equip your dodge items, the final result may not be correct. A work around for it was stripping off and re-equipping in a different order.