Threshold: Some monsters have a very tough hide that will allow them to ignore attacks that do only small amounts of damage. A monster with a threshold of 10, for instance, would only be affected by damage of 11 or more. If you are striking the creature, the NPC will tell you “No Effect” to indicate that you are hitting it but do not seem to be hurting it. If you can exceed the limit of the hide, then the creature will take full damage from your blow. A Killing Blow can always go through a Threshold. Spell Defenses and suits of armor are affected by all blows, even if the creature wouldn’t normally be affected. However, armor and spells must be taken into consideration as they are counted before the Threshold.

For example: Fangthorn the troll has a Threshold of 4 and a suit of armor worth 10 Armor Points. He is attacked by Terin, who is calling “three normal.” The first few hits from Terin will breach Fangthorn’s armor. After those 10 points are lost, Fangthorn will begin saying “no effect” to the rest of Terin’s blows since they are now affecting only his body.

Some monsters may even have a “reverse threshold” where any damage above a certain amount has no effect.