Disarm is a special attack associated with fencing blades and warder mobs. While these 2 events are both appropriately called disarm, they are entirely different in nature and should not be confused.
Fencing Blades[]
Historically, fencing blade disarm resulted any time an opponent wielding a 1-handed weapon was successfully hit during combat by an opponent wielding any fencing blade. This allowed a fencing blade user to completely counter any armor wearing opponent (an abser, who do not typically rely on defense) who would be disarmed by 100% of hits. Two-handed weapons cannot be disarmed by fencing blades through the traditional mechanism.
Eventually, fencing blade disarm was downed significantly to result in a significant decrease in the frequency of disarming.
When an opponent is disarmed their weapon is either disarmed to their inventory or to the ground, though the rate of disarming to the ground is significantly less than to inventory.
Warder Mobs[]
Warder mob disarm is entirely different than fencing blade disarm. When an opponent engages a warder mob, such as a tense warder, the warder mob executes a disarming attack which disarms its opponents weapon to the ground regardless of whether they are wielding a 1-or-2 handed weapon.
This attack is one of the most feared attacks in the game and part of the incredible defenses that makes the city of Tar Valon so difficult to assail. This attack also makes combat at any warder patrol extremely dangerous for darkside or opponents of Tar Valon because once an opponent's weapon is disarmed it can be picked up by another human protagonist. Shadowspawn attacking humans at patrols containing warders have lost unique weapons in the past when warder disarm allowed the human opponent to pick up the disarmed weapons.