Disorient, also called stun, is a Status Effect. An enemy under the affects of a Disorienting power is unable to activate click or toggle powers, and can only move slowly by staggering. Disorienting also shuts off any running toggle powers. It has no effect on auto powers.
Problems With Disorient
Although they're greatly slowed, players remain in control of which direction they move while disoriented. Critters, on the other hand, move in random directions.
A critter that's Disoriented while moving from Point A to Point B will continue moving to B at its original direction and speed. Only then will it begin moving slowly and randomly. Furthermore, Disorienting apparently applies no penalties to flight speed, jump speed, or jump height, so enemies that have automatic, unsuppressible travel powers can move at unexpectedly high speeds.
Magnitude, Resistance, Protection
Except for Slows, all status effects work the same way. The target has both Resistance and Protection. In order for the attack to take effect, it must have a big enough Magnitude to overcome the Protection. Once the Protection is overcome, the duration of the effect depends on the target's Resistance. Attacks can stack in order to overcome a target's Protection. No Slow Protection exists, only Resistance.
PVE: Minions have a Protection of 1. Lts are 2. Bosses are 3. Elite Bosses are 6. The Purple Triangles of Doom on an Archvillain or Hero add 50 to all but Sleep while they are up. Some specific enemies are resistant to fear.
PVP: As of Issue 13, Protection does not exist in PVP, only Resistance.
How to tell if a power uses stun
|Clobber Melee Foe Disorient Mag 3|
This power is found in the War Mace power set for Tankers and Brutes.