I have No Problem with destroying the pcs gear, because being mean to them gives me a chane to be nice to them.
You can do it too much and I have not yet used a rust monster IMC but I have sundered the dwarfs most prized waraxe, the look on his face was priceless!
Unfotunaly the cleric mended it..darn it!
(he had a back up weapon and a weaponsmith back at camp that could fix it for him..oh well!)
But not to hijack the thread with the "sunder" controversy!
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So this seems like kind of a dumb question but:
Do you allow the attack that causes damage to "the rusty" actually hurt it?
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We have run an encounter using just 1 so far and both our group's "other dm" and myself agreed it was amussing to not let the weapon even hurt it because the item
Instantly turns to rust and is ruined.
It makes the rusty pretty scary that way!
I knew what the creaure was because as a player I am (besides the other dm) the most experienced and also Dm my own game, so the dm let my pc, a dwarf, make a knowledge check to verify what it was (my reasoning was that dwarves Love metal and a rusty wuold be a blight in their eyes so they would know to look out for them).Our party's cleric..did something to stun it for a round, I don't remember what, and then my chacter dropped a couple of Master Crafted longswords we found and ran back the other way.
One of the players was flipping out because of "all the money (I) had just thrown away" but I told him that both he and the cleric should be glad that we only lost a couple of swords we weren't using, rather than lamenting the loss of the clerics Banded armor and His Greatsword! We were trapped in an series of underground passages and had not yet been able to find the way, we knew that we would likely have to fight a red dragon because of rumours we had heard back in town, (quite some distance away) and that all we could count on was what we had on us and what we may get lucky and find.
I did propose that our characters could "strip down" and go back with clubs (we had found some goats peend in a wooden pen) and kill it but he was reluctant for some reason..go figure!
But I find that because the Rust Monster is so distinctive that the players will likely know what they face unless you "wolf in sheeps clothing" it.
Sorry for the long post!