Freezing Floor Tiles

Level 16Hazard (Complex)
HazardMediumLegacy
AC
36
HP
40
Speed
0 ft.
Perception
+0
Fort
+33
Ref
+30
Will
+0
Stealth
+23
Recall Knowledge DC 35 (arcana)
Disable DC 40 thievery (legendary) or Dispel Magic (6th rank; counteract DC 38) to disable one of the sensors

Four remote sensors at each corner of the arena cause bursts of freezing magic to erupt from random tiles on the arena and stop creatures in their tracks.