Mighty Gorgons

You are absolutely right; if you have 10 Gorgons, there is a 100% chance they will kill one monster from the enemy stack, but more than one might die. Everything falls within a range; the probability that 1 will die is 1-100%, and the probability that all 10 will die is 0.00000000001 (you need to multiply the probabilities; 0.1 raised to the power of 10). This gives us a range from 1 to 10, with the probability of the event expressed as a percentage.