These are all the status effects, from http://forum.bioware...ombat-mechanics
Status Effects
- Burning: Target takes fire damage over time. Does not stack.
- Chilled: Target suffers reduced movement speed. Does not stack.
- Shocked: Target suffers a flat -20% penalty to fire, cold, and electricity resistance. Does not stack.
- Stunned: Target is unable to move or take any action.
- Asleep: Target is unable to move or take any action. Taking any damage ends the effect.
- Frozen: Target is unable to move or take any action.
- Paralyzed: Target is unable to move or take any action.
- Fear/Panicked: Target runs in random directions and is unable to take any other action. Taking any damage ends the effect.
- Sundered: Target suffers reduced armor. Stacks multiplicatively.
- Weakened: Target suffers reduced damage output.
- Poisoned: Target takes poison damage over time. Poison damage ignores armor. Does not stack.
Add on top of those the physical effects of knock-back and knock-down. Also Taunted and Bees, which are not listed above for some reason.
All dragons in the main game have these traits:
- Immunity to all disabling effects
- Immunity to Slowed
- Perceptive
- Greater (Element) Resistance
- Vulnerability (to opposite Element)
So what does all that mean? I believe it means that dragons are not affected by:
- Chilled (regardless of resistance, since they are immune to the slow effect of Chilled)
- Stunned
- Asleep
- Frozen (regardless of resistance, since they are immune to the disabling effect of Frozen)
- Paralyzed
- Fear/Panicked
- Knock-back
- Knock-down
Furthermore, status effects that cause elemental damage, like Burning, are reduced to 1 point of damage if the dragon is resistant to that element.
I believe they are affected by the rest, including Sundered. I have an old video where I can see the Sundered effect being applied to a dragon, but it is pre-Trespasser so who knows if that is really proof?
So while Solas's Veilstrike won't apply knock-down to a dragon, it will apply Weakened if you have that upgrade.
Mark of the Rift does seem to be some kind super-override power on dragons, since according to all of the above, it shouldn't slow them down. But it does, no question about it.