Baldur's Gate II: "Talk Lock" / "Fake Talk" trick
An engine bug that affords the player an easy way to kill any NPC that will initiate combat after talking to them. Just use the "talk" command as though you were about to initiate dialog, move away before you get close, then use another character to attack them. The NPC will stay idle for a few seconds waiting for your character to approach and talk to them, and during this period they will not respond to any hostile action whatsoever. Wait a second or two, then "talk" to them again. Repeat the process until they die.
NOTE: This should not be used against enemies who have scripted events which trigger mid-battle (ie Kangaxx, Lavok and Irenicus), as it will prevent them from ever dying. However, it works perfectly fine on most NPCs, liches, dragons, and even Drizzt!
This does not work in the Enhanced Edition!