Technically the only “ooze” in the game, the gray ooze is the monster one of my players asked some specific questions about.  I suppose that might make this a very short series, though by 2nd edition all slimey monsters (green slime, gray ooze, gelatinous cube, etc.) get filed under the moniker ooze.  Actually, the real reason for the title is simply my preference for alliterative titles.  Let’s get on with it.

Let me start by summarizing my player’s questions:

Shouldn’t it have taken a full turn (10 minutes) for the gray ooze to dissolve our armor?  Also, the text says nothing about it destroying weapons.

They recently lost a magic sword fighting a gray ooze, so naturally they’re a bit distressed.  These questions are rooted in the B/X description, so I’m actually going to start there.  A bit backwards, I know, but don’t worry we’ll look at the OD&D description next.  For now, here’s B/X:

This seeping horror looks like wet stone and is difficult to see. It secrets an acid which does 2d8 points of damage if the gray ooze hits bare skin.  This acid will dissolve and destroy magic armor in one turn.  After the first hit, the ooze will stick to its victim, automatically destroying any normal armor and doing 2d8 points of damage each round.  Gray ooze cannot be harmed by cold or fire, but can be harmed by weapons and lightning.

What an unusual description.  Certainly there is text in there about it taking one turn to destroy magic armor.  How odd to list the special case (magic armor vs. normal) first, given that the next sentence directly states that normal armor is destroyed in a single round.  I didn’t even notice the second bit myself until typing it out above, and assumed B/X was going to tell me that all armor takes a full turn to destroy.  Probably my player made the same mistake.  Also, the player is correct, no mention of destroying weapons, or any other material other than armor.  Of course, one can infer that acid that can eat through armor can also eat through a sword.  And why is lightning specifically called out here?  Is it not susceptible to all forms of magical attack that are not fire or cord (eg. magic missile)?

Side note: Mentzer edition and Rules Cyclopedia are essentially identical, though the text is rearranged to make a bit more sense.  Also, RC changes “magic armor” to “magic items”.

OK, let’s pop back to OD&D for some context:

A seeping horror which closely resembles wet stone and is thus difficult to detect. It will not be spread by non-harmful weapons, but it is subject only to lightening bolts or cuts and chops by weaponry, for it is impervious to cold or fire. It does not harm wood or stone, but it corrodes metal at the same rate that Black Pudding does. It does two dice of damage to exposed flesh for every turn it is in contact with it.

And since it references it, here’s Black Pudding:

Another member of the clean-up crew and nuisance monster, Black Puddings are not affected by cold. It is spread into smaller ones by chops or lightening bolts, but is killed by fire. Black Puddings dissolve wood, corrode metal at a reasonably fast rate, have no effect on stone, and cause three dice of damage to exposed flesh. If an armored character runs through a Black Pudding the monster’s corrosive power will eat away the foot and leg  protection of the armor so that it will fall-away next turn. Black Puddings can pass through fairly small openings, and they can travel as easily on ceilings as on floors.

Clearly the whole special mention of lightning bolts is for specific comparison to Black Puddings, which have a specific reaction to lightning (splitting into multiple puddings).  As for destroying metal, it does so “at a reasonably fast rate”, whatever that is.  There is one mention of turns here, that when running through a pudding the foot and leg protection will “fall-away next turn.”  My first instinct was to say that here’s another confusion of rounds vs. turns in OD&D.  However, I suspect what’s going on here is the supposition that combat is not being entered, and thus the party movement through the dungeon is being tracked by turn.  The party in question here decides to push through a passageway totally ignoring the black pudding and walking right through it, the result of which is that the next turn (which is immediate when tracking movement by turn) the armor dissolves.  Interesting that the assumption here is that the black pudding does not pursue and attack, making it almost more like a trap than a monster.

Also as a side note, I’m tickled here by the direct reference to these monsters being “member[s] of the clean-up crew”.  You can just see the thought process of how these things were invented.  They players start to wonder what happened to all those orc bodies that they killed last time they were in this passage.  The DM, thinking quickly, replies “a gelatinous cube must have got them.”

Anyway, let’s look forward now to AD&D 1st edition.  Remember that the Monster Manual was the first printed AD&D book back in 1977, four years before B/X is printed:

This creature corrodes metal at the same rate a black pudding (qv) does, i.e. chainmail is eaten through in a single melee round.  Its acids do no harm to stone or wood.  Spells do not harm this creature, and it is impervious to heat or cold.  Lightning, however, causes full damage to gray ooze, as do blows from weapons.  Note, however, that in the latter case the weapons striking the creature may corrode and break.  They strike like snakes when attacking.

Being AD&D there are of course several more paragraphs, but the one above is the most interesting for comparison.  Again we must consult the Black Pudding entry for specifics on the metal corrosion ability.  Here’s the pertinent bit:

Black puddings also eat away metal with their corrosive saliva: Chainmail in 1 melee round, plate mail in 2, and an additional melee round for magical armor at a rate of 1 melee round for each plus of armor.  Thus, +1 magic (plate) armor would have to be in contact with a black pudding for 3 melee rounds before it dissolved.

OK, as usual AD&D has to add some flourishes, now separating number of rounds for normal armor based on type.  No mention of leather here though — are we to assume that like wood and stone, leather is also impervious to the gray ooze’s acid?  Interestingly magic armor is dissolved much more quickly here than in B/X, especially considering the differing rounds per turn in each.  In AD&D, 1 round = 1 minute, thus 1 turn (10 minutes) = 10 rounds.  In B/X, 1 round = 10 seconds, thus 1 turn (10 minutes) = 60 rounds.  Wow, in AD&D my +1 plate armor takes one twentieth the time to dissolve as it does in B/X!

Also, did I just see that these things are totally immune to all magic except lightning bolts?  Holy crap!  For a 3 HD creature, this thing has serious potential towards TPK.  In AD&D, I’m thinking the best bet is to just run away.  In 2nd edition AD&D not much has changed, the description is simply a bit more concise:

The gray ooze strikes like a snake, and can corrode metal at an alarming rate (chain mail in one round, plate mail in two, and magical armor in one round per each plus to Armor Class). Spells have no effect on this monster, nor do fire- or cold-based attacks. Lightning and blows from weapons cause full damage. Note that weapons striking a gray ooze may corrode and break.

I’m noticing now this recurring thing of no real guidance on how likely it is a weapon striking it will corrode and break.  Simply that it may.  Does the weapon get an item saving throw?  I would argue yes, but there’s no text indicating such here.

Here’s the 3.0 edition (again, just the pertinent metal corroding and immunities parts):

Ooze: Immune to mind-influencing effects, poison, sleep, paralysis, stunning, and polymorphing. Not subject to critical hits.

Acid (Ex): A gray ooze secretes a digestive acid that quickly dissolves organic material and metal. Any melee hit deals acid damage. The ooze’s acidic touch deals 40 points of damage per round to wood or metal objects. Armor or clothing dissolves and becomes useless immediately unless it succeeds at a Reflex save (DC 19). The acid cannot harm stone. A metal or wooden weapon that strikes a gray ooze also dissolves immediately unless it succeeds at a Reflex save (DC 19).

Hmm, now wood is also not safe, but at least our weapons and armor get saves.  Magic immunities have also been reduced to some very specific effects.  Here’s 3.5:

A gray ooze secretes a digestive acid that quickly dissolves organic material and metal, but not stone. Any melee hit  or constrict attack deals acid damage. Armor or clothing dissolves and becomes useless immediately unless it  succeeds on a DC 16 Reflex Save. A metal or wooden weapon that strikes a gray ooze also dissolves immediately unless it succeeds on a DC 16 Reflex save. The save DCs are Constitution-based.

The ooze’s acidic touch deals 16 points of damage per round to wooden or metal objects, but the ooze must remain in contact with the object for 1 full round to deal this damage.

Getting weaker here, the save DC is down by 3 points and are now based on Con rather than Dex (not sure how that’s pertinent to item saving throws, but my 3.5 knowledge is a bit lacking). Also I don’t see anything here about immunities to any kinds of spells.

The interesting thing I’m noticing here is that it looks like after OD&D, AD&D made this creature super hard while B/X made it much weaker, and then subsequent editions have progressively tried to find a middle ground.  The whole magic immunities thing I find very strange and really not appropriate for a 3 HD monster.  You might argue that the authors of B/X felt the same, though they may have simply been pulling from OD&D which makes no mention of such immunities.

So why the additional pull back on duration to destroy magic armor, and no mention at all about weapons in B/X?  Well, one interesting thing to note about the gray ooze in B/X is that it appears in the red book.  Yeah, that’s right, the authors thought this was an appropriate monster for levels 1-3.  Ouch!  It’s possible they thus decided to try and dial back some of its deadliness.  Also, as for weapon destruction, I’ll point out that item saving throws are not introduced until the Expert book, and even then the text is extremely limited:

The character’s equipment is assumed to survive if the character survives.  If the character is killed by a special attack form (fire ball, dragon breath, etc.) normal equipment is considered destroyed.  The DM may give magic items a saving throw equal to that of the character, and may allow a saving throw bonus equip to the item’s bonus in combat, if any (armor +2 saves at +-2, a ring of protection +1 saves at +1, etc.).

Expert Book, Page X24

This only seems to apply when the character is out right killed by the attack.  It makes no provision for attacks that specifically target the item.  Still, it is at least a starting point for introducing item saving throws when desired.

How will I rule it?  Likely I’ll just pull back to OD&D, being closest to what feels right to me.  I think the intention with these things is clearly to let them destroy armor, and taking 60 rounds to do so sounds bizarre.  It also begs the question, can the armor be saved in those 60 rounds?  There’s no mention of that here.  To keep things simple, I’d say armor and weapons both get a single save, and if they fail they are immediately destroyed.  OK, it may take some time for the acid to fully destroy the thing, but within the round they are damaged enough to no longer be used for their intended purpose.

So there you have it, the gray ooze.  I had no idea it varied so much between editions.  I’m kind of tempted now to look at the Rust Monster for additional comparisons.