Frozen is a status effect the deals damage over time as well as slows the target. If the effect is stacked on itself the target will not be able to move.
The Mage class Is the only class that can use this at the moment. The damage over time from this effect verys on the charactors Cold Magic skill level.
Monsters can spawn with the effect Frozen. This effect will give them the abilitly to infect the charactors with Frozen. The damage from this verys with the level of the monster.