This ability from its trait reads: "Target enemy is immobilized for 3 rounds unless they resist"
Whenever I get this cast on me, my movement does not change at all. And I did not resist it.
I had a quick look in the XMl and it looks like the spell is supposed to reduce its target to 0 move, and 0 dodge. While my dodge does get reduced to 0, my moves do not.
