Cancel Magic success is random
 

Cancel Magic has randomness to it, and I couldn't find any evidence that it should.

Testing by dispelling my charmed pet (who had no other buffs) and dispelling Breeze on myself, I observed dispelling either required between 1 and 4 casts of Cancel Magic. Below are logs for dispelling Breeze, which demonstrate a case where 4 Cancel Magic casts were required, immediately followed by a case where only 1 Cancel Magic cast was required.

Someone suggested that spell counters may be the cause; however, that doesn't explain the randomness. My understanding is that the dispell counters only apply to disease and poison debuffs. For example, Plague has 9 disease counters, so you'd need to decrease the disease counters by at least 9 e.g. exactly 2 casts of Counteract Disease (A single cast removes only 8, so you need a 2nd cast to remove at least 9 counters). There is no randomness in that scenario. (I don't have disease or poison spells to verify they have no randomness, but this is how it was explained to me.)

Unlike poison/disease, magical buffs and debuffs like Charm and Breeze don't have any "counters", so shouldn't 1 cast of Cancel Magic remove exactly 1 buff/debuff?

Moving to resolved as the have been some cancel magic changes since OP, and I am pretty certain there are counters on buffs and some associated randomness to dispell.