I don't DM 4th edition, but when I do

[Wormwood]

and I'm not sure this is correct, please let me know if not), is a rust monster not a million times more useful than a well stocked magical bazaar in 4E?

Not quite correct. It simply renders your item down to its value in residuum, leaving you in your underwear and/or armed with a stick until you can a) get back to town and get new equipment or b) wait around for a ritual-casting PC to make something for you of his level or lower.

 

[Jawsh]

I mean, based on what I'm hearing here (and I'm not sure this is correct, please let me know if not), is a rust monster not a million times more useful than a well stocked magical bazaar in 4E? Tired of that tiara of Disney Princess +3? Sell it for a crappy 2,000 gold, or feed it to your captured rust monster for residiuuuuuum to make a 10,000 gp He-Man Power Sword +2!

A rust monster. No home is complete without one.

I like the flavour there. I think officially in 4E it's a lot easier than that. Basically a wizard can automatically deconstruct magical items to get at the tasty residuum centre. However, I really like the idea of a wizard's laboratory having a bunch of cages with baby rust monsters in.

 

[Crazy Jerome]

Back when I used to occasionally run a game for the local Con, sometimes I'd advertise a distinctly non-standard game. I never had anyone complain about the way it was run. I did have a few instances where no one that signed up, showed up, and I ended up playing in a nearby Spycraft game instead of running mine. But I choose to believe that was because it was 11:00 P.M. when it kicked off, and not a rebellion against my plans.

 

[Griego]

(This following post is meant to be read in a jokey fashion, no offence intended!)

Ah yes, the universal Law of Conservation of Magic, first discovered by... wait a minute... there isn't a Wikipedia article on this - IT DOESN'T ACTUALLY EXIST!!!

The magic just goes. The rust monster, fine exemplar of the laws of entropy, just ruins it for everyone. That being the point of a rust monster. That you should fear it, not so much for its terrible ferocity, but rather for the fact that it can munch your bling.

I mean, based on what I'm hearing here (and I'm not sure this is correct, please let me know if not), is a rust monster not a million times more useful than a well stocked magical bazaar in 4E? Tired of that tiara of Disney Princess +3? Sell it for a crappy 2,000 gold, or feed it to your captured rust monster for residiuuuuuum to make a 10,000 gp He-Man Power Sword +2!

A rust monster. No home is complete without one.

This breaks verisimilolitude. Stop restricting my narrative!

 

[Griego]

Seriously though, what do DMs get out of this? Because every player I've ever met hates it when their items go poof so easily. I've toyed around with the idea of such encounters in every campaign I've run, but I just don't use monsters like this because it's too much of a downer when the players' hard-earned loot is destroyed just like that. If you have the rare group that is into it, fine, but you better be sure they really are ready. I've heard a few stories of players who said they were ok with it, but when it came down to it they realized they weren't, after all. XD

 

[Jawsh]

Well, I'd say the proper way to run a rust monster encounter is with a little bit of warning ahead of time, and a chance for the players to outsmart it. Maybe treat it as a skill challenge instead of a combat encounter.

It's pretty much become accepted nowadays in a dungeon encounter, when asked "where did this creature come from" to reply "a mad wizard created it." But if you give that a bit of thought too, maybe you can actually use that as a bit of a story. Maybe a wizard created the rust monster by enchanting one of his pet lizards to eat metal. Maybe he made it specifically for the purpose of disenchanting items. The upside with this though, is that the wizard obviously had a purpose, and that purpose was probably the making of other items. Those items should be available if the PCs know where to look.

Alternatively, a rust monster could live in its own lair where dozens of adventurers and wandering kobolds have passed. There won't be any metal items in the lair, but there really ought to be plenty of nonferrous treasures. So it's a trade-off, if the players lose their metal stuff, they gain some non-metallic treasure.

 

[Jawsh]

He made do with a +1 axe, by the way. Very unhappy.

Oh yes, I feel so sorry for the fighter who lost his glowing, magical axe of awesome, forced to use a slightly less glowy, slightly less awesome magical axe. Boo hoo. [/world's smallest violin]

 

[Vyvyan Basterd]

For D&DN I'd like to see an approach that falls in the middle.

I want the rust monster's attacks to be capable of destroying weapons and armor. Just not instantly and not with leftover residuum. Watching your weapon slowly rot away at each touch of the foul beast you are trying to dispatch and hoping you can kill it before it finishes its meal sounds more exciting to me. If you suceed, then the party crafter can help repair your item.

I want a medusa to be able to turn you to stone. Just not instantly. Feeling your joints start to stiffen, feeling your weapon arm getting heavy, the crackling of stone slowly tracing its way across your skin. That's exciting to me.

Insta-death or Insta-suck don't appeal to me anymore, but a gradual, dramatic path towards doom sounds much cooler.

 

[Wormwood]

Oh yes, I feel so sorry for the fighter who lost his glowing, magical axe of awesome, forced to use a slightly less glowy, slightly less awesome magical axe. Boo hoo. [/world's smallest violin]

It was annoying to be honest. We'd all wished we'd been playing in a 1e module so at least he could grab one of the dozens of magic weapons lying around to replace our losses.

 

[Siberys]

Also, there is a ten level difference between when a +1 item is expected per the math and when a +3 item is expected. That is a major loss. We're talking losing out on +2 to attack (the equivalent of being constantly marked, by everything), +2 damage (not too much of a loss, admittedly, but that stacks up quick), and +2[W] on a crit (that's not too likely to come up often, but boy do you wish you had it when it does come up).