If I'm reading the slayer weapon guide correctly, then Undead should drop repond slayer instruments/weapons. Currently, the Ancient Lich drops silver instruments. This doesn't seem correct.
The aincient lich is a non-slayer dropping monster. All non-slayer droppers will drop silver instruments by default.
We are working to get a few new pages added to the compendium to help with this. The monster pages were re-worked last night to incorporate the slayer information. These names should be clickable soon to display a list of the monsters that are weak vs and drop various slayers. As for the ancient lich I will check with Ezekiel and see if we need to add that to the correct undead slayer groups.
