So I’m making a document, mainly for myself but I will put it up on drive thru for others to use, of 200+ magic items converted from D&D to use for Dungeon World, complete with random treasure tables to roll on. I am making a couple different “_____ Slayer” items that are meant to deal with certain kinds of creatures. My question to the group is, would the weapon dealing more damage to that certain creature be appropriate? Or would something else be better? I thought maybe just ignoring any defenses of the creature would be good, but then I thought of giants wearing armor and it not making sense for a weapon to ignore their armor. Right now I just have them dealing 2d6 additional damage, but I thought that may be boring.
I also considered something like this:
When you strike a creature this weapon was made to kill, on a hit (7+) you deal an additional 1d6 damage. On a 7-9, the creature also realizes the nature of the weapon and acts accordingly. On a 12+ the creature is instantly slain.
Is killing the creature outright on a 12+ too powerful? Say for like, a dragon or something similar. Let me know what you all think!