Ways to deny dex to ac:
Attacker is:
Invisible Condition:
-Specifically granted by Invisibility spell.:
-Blinking
When defender is under the following conditions:
Blinded
1st Color Spray - 20ft? - Will?
2nd Blindness/Deafness - Touch - Fort
2nd Glitterdust -
2nd Pyrotechnics - 120ft radius - Will
3rd Flashburst -
4th Contagion - Touch - Fort DC 16 twice
4th Orb of cold - Close - Fort
4th Holy Smite (good)
5th Prismatic Ray - Close - No save under 6HD
6th Ray of light -
7th Power Word Blind - Close? - No save under 200HP
7th Prismatic Spray - 60' - No save up to 8HD
7th Sunbeam - 60' - Reflex
8th Prismatic Wall - Close/20' - No save under 8HD
8th Sunburst - Long/80' Burst - Reflex
9th Prismatic Sphere - 20' - No save under 8HD
3rd Remove Blindness/Deafness
Concealed or invisible... no notation, see concealment
3rd Blacklight - 20' radius - None
Cowering
'-2 AC, lose dex, can take no actions.' When you are unable to flee when panicked.
Flat Footed
Suprised
Balancing
Climbing
Grappling (ranged attacks roll randomly to hit either combatant)
4th (Edvard's) Black Tentacles
7th Grasping Hand
7th Ice Claw
Stunned
1st Color Spray
2nd Sound Burst
3rd Great Thunderclap
7th Symbol of Stunning
7th Word of Chaos
8th Power Word Stun - No save <150HP
8th Scintillating Pattern - Close - No save <12HD
8th Shout, Greater - 30' - Fort
Dex treated as 0 (-5 modifier), able to be sneak attacked.
Helpless (-4 AC to melee, but no AC penalty to ranged)
Bound
Sleeping
Paralyzed
Unconscious
Subdual Damage
Otherwise at your mercy
Pinned (Do note about ranged attacks hitting grappling combatant.)