Baldur's Gate : The Sword Coast Chronicles : NWN2 Persistent World

I was fighting the gnoll boss on the second floor when my rapier was suddenly unequipped and taken off my hotbar. Thankfully, it didn't drop, merely enter the last page of the inventory.

I feel this kind of ability by creatures is too likely to happen with a full inventory, causing weapon lossage.

never ever have a full inventory

Done. Likewise report any creature that has disarm, they should not have it.

Why ? - that spices the dull combat up a bit

I agree, that no creature should have improved disarm and steal players weapons.

The phase spiders at n-w cloakwood have it.