Spells Through The Ages – Transmute Rock to Mud

Let's say you have a formerly firm establishment and you want to collapse the whole thing; your preference to have it be a big sludgy morass instead. Degrade your opponents via a real mud-slinging contest. How to do that? Well, of course: transmute rock to mud is your huckleberry.

Original D&D 

Transmute Rock to Mud: The spell takes effect in one turn, turning earth, sand, and of course, rock to mud. The area affected is up to 30 square inches. Creatures moving into the mud will become mired, possibly sinking if heavy enough or losing 90% of movement otherwise, unless able to fly or levitate. The spell can only be countered by reversing the incantation (requiring a Transmute Rock to Mud spell) or by normal process of evaporation (3-18 days as determined by rolling three six-sided dice). Range: 12".

This spell was not ever included in Chainmail Fantasy -- which is a bit surprising, because to my eye it looks tailor-made for an outdoors mass-combat use case. (Compare to: move earth, et. al.) So we start with Original D&D (5th level spell); as shown above, the primary thrust of the spell seems to be in creating a large muddy field to obstruct the progress of one's enemies. While a surface area is given, no depth is mentioned; so it might be unclear whether victims can possibly drown or not.

The duration is a little unusual for two different reasons. One is that it is the first magic-user spell in the game to imply that it can be "reversed" to create its opposite effect. There is no general rule for this in OD&D; and in fact it is only one of two such magic-user spells which allow that (the other: stone to flesh at 6th-level). This is in contrast to about half the spells on the clerical list which are underlined, indicating that they are (automatically) reversed by evil clerics.

The second oddity being the fact that over many days the effect may just wear off naturally; I don't think that there's any other spell in the game that functions likewise. In the Swords & Spells master table, the duration is listed as "full game".

Expert D&D 

Transmute Rock to Mud
Range: 120'
Duration: 3-18 days
 
This spell changes a volume of rock up to 3,000 square feet and 10' deep, to a morass of mud. Creatures entering the area of mud may be mired and are slowed to l/10th of their normal movement speed.

The reverse of this spell (transmute mud to rock) changes up to 3,000 square feet of mud (10' deep) to rock. The effect of this reversed version is permanent.

Cook's version in Expert D&D is almost identical. The 3-18 days duration here would most likely be interpreted as a (very weird, very random) duration for the magic itself, not an effect of natural evaporation. The effect on earth and sand is not mentioned. Cook does give a depth figure for the first time -- a fixed 10', so one might think that drowning is a possibility, but the effect otherwise specified seems to only indicate slow movement (swimming?).

Note that Expert D&D does have a general system for reversal of both magic-user and clerical spells,  indicated by an asterisk in the spell rosters -- many such clerical spells are given (as above), but still fairly few magic user spells (6 spells out of a total of 72 by my count).

AD&D 1st Edition

Transmute Rock To Mud (Alteration) Reversible
 
Level: 5 
Range: 1"/level 
Duration: Special 
Area of Effect: 2 cubic "/level
Components: V, S, M
Casting Time: 5 segments
Saving Throw: None

Explanation/Description: Except as noted above, and that the material components for the spell are clay and water (or sand, lime and water for the reverse), this spell is the same as the fifth level druid spell, transmute rock to mud.

The druid spell description saying this:

Explanation/Description: This spell turns natural rock of any sort into an equal volume of mud. The depth of the mud can never exceed one-half its length and/or breadth. If it is cast upon a rock, for example, the rock affected will collapse into mud. Creatures unable to levitate, fly, or otherwise free themselves from the mud will sink and suffocate, save for lightweight creatures which could normally pass across such ground. The mud will remain until a dispel magic spell or a reverse of this spell, mud to rock, restores its substance - but not necessarily its form. Evaporation will turn the mud to normal dirt, from 1 to 6 days per cubic 1" being required. The exact time depends on exposure to sun, wind and normal drainage. The mud to rock reverse will harden normal mud into soft stone (sandstone or similar mineral) permanently unless magically changed.

We see that as in Cook's work, the effect on non-rocky earth and sand seems to be removed. The area is now actually a volume, variable by level (as for most spells in AD&D), and the depth is now an algebraic calculation based on min(length, breadth)/2, subject to available volume. Sinking and suffocating are explicated for the first time. Evaporation is now made even more vague for the DM ("depends on exposure to sun, wind and normal drainage"; I prefer the flat 3d6 roll if we must do that). A description of the effect on a single discrete "rock" is given for the first time, as well.

The DM's Guide gives this additional errata/information:

Transmute Rock To Mud:  Rate of sinking is  1'  per segment, i.e.  1'  per  6 seconds or  10' per minute (round). Brush thrown upon the surface will stop sinking of creatures able to climb atop it (use discretion  as  to the amount of brush and the weight of creatures). Ropes can be used to pull creatures out of the mire, assuming that sufficient power  is  available  -  1 man/man, 10 men/horse (or vice versa).

In 1986 Doug Niles' Dungeoneer's Survival Guide included a section on running Battlesystem engagements in the depths of the underworld (recall that Niles was himself the author of the well-received Battlesystem supplement for D&D). In a subsection on "Cave-ins On A Battlefield", he writes (p. 35):

Spells such as earthquake and transmute rock to mud are commonly used for this purpose. If a ceiling collapses, the area affected on the ground is the same as the area of the ceiling collapsed, plus 1" in all directions. Such a collapse does 6d8 hit points of damage to all creatures in the area of effect; a saving throw vs. spell reduces the damage to half. Thus, an orc figure representing 10 orcs suffers 60 dice of damage, and is automatically destroyed whether it saves or not.

A similar weight of mud falling on a unit inflicts only  4d8 points of damage, again halved if a saving throw is successful. 

While that's a logical extrapolation of the spell's effect, I'm not sure that I'm entirely satisfied by that. More on that thread below. 

AD&D 2nd Edition

Transmute Rock to Mud
(Alteration)
Reversible

Range: 10 yds./level
Duration: Special
Area of Effect: 20-ft. cube/level
Components: V, S, M
Casting Time: 5
Saving Throw: None

This spell turns natural rock of any sort into an equal volume of mud. The depth of the mud can never exceed half its length or breadth. If it is cast upon a rock, for example, the rock affected collapses into mud. Creatures unable to levitate, fly, or otherwise free themselves from the mud sink at the rate of 10 feet per round and suffocate, except for lightweight creatures that could normally pass across such ground. Brush thrown atop the mud can support creatures able to climb on top of it, with the amount of brush required subject to the DM's discretion. The mud remains until a dispel magic spell or a reverse of this spell, mud to rock, restores its substance--but not necessarily its form. Evaporation turns the mud to normal dirt, at the rate of 1d6 days per 10 cubic feet. The mud to rock reverse can harden normal mud into soft stone (sandstone or similar mineral) permanently unless magically changed.

The material components for the spell are clay and water (or sand, lime, and water for the reverse).

This is mostly another copy-and paste job from the 1E text, with the detail from the DMG about sinking rate and use of brush for floatation inserted. The duration is again given as due to evaporation, but the factors affecting that in 1E are removed, at least for the wizard version -- in the alternate priest spell, it is still there ("The exact time depends on exposure to the sun, wind, and normal drainage.").

D&D 3rd Edition

Transmute Rock to Mud
Transmutation

Level: Drd 5, Sor/Wiz 5
Components: V, S, M/DF
Casting Time: 1 action
Range: Medium (100 ft. + 10 ft./level)
Area: Up to two 10-ft. cubes/level (S)
Duration: Permanent (see text)
Saving Throw: See text
Spell Resistance: No

This spell turns natural, uncut or unworked rock of any sort into an equal volume of mud. Magical or enchanted stone is not affected by the spell. The depth of the mud created cannot exceed 10 feet. Creatures unable to levitate, fly, or otherwise free themselves from the mud sink until hip- or chest-deep, reducing their speed to 5 feet and giving them –2 penalties on attack rolls and AC. Brush thrown atop the mud can support creatures able to climb on top of it. Creatures large enough to walk on the bottom can wade through the area at a speed of 5 feet.

If transmute rock to mud is cast upon the ceiling of a cavern or tunnel, the mud falls to the floor and spreads out in a pool at a depth of 5 feet. The falling mud and the ensuing cave-in deal 8d6 points of damage to anyone caught directly beneath the area, or half damage to those who succeed at Reflex saves.

Castles and large stone buildings are generally immune to the effects of the spell, since transmute rock to mud can’t affect worked stone and doesn’t reach deep enough to undermine such buildings’ foundations. However, small buildings or structures often rest upon foundations shallow enough to be damaged or even partially toppled by this spell.

The mud remains until a successful dispel magic or transmute mud to rock spell restores its substance —but not necessarily its form. Evaporation turns the mud to normal dirt over a period of days. The exact time depends on exposure to the sun, wind, and normal drainage.

Here's the 3rd Edition version of the spell; longer (as usual), but mostly the same -- in terms of volume, duration, use of brush, evaporation, and factors effecting evaporation (most of that copied forward from the 1st Ed rules). In the standard 3rd Ed. safety-bumpering, the possibility of suffocation (seen in 1st-2nd Ed.) has been removed, and victims can at most "sink until hip- or chest-deep", even though no rational mechanic for that is given.

But probably the most important changeover the entire evolution of the spell happens in the first line here: it is limited, for the first time, to working against "natural, uncut or unworked rock". That's a pretty big change, whose details are spelled out in the 3rd paragraph. We might think that a pretty common-use case is for a band of heroes or villains to be confronted by an opposing keep and think: "Hey, that castle's stone. If we just cast one transmute rock to mud, that whole gatehouse will just collapse, right?" In the 1E era, I definitely thought that was the implication, even though it was never specified in any version of the spell; here that is prohibited due to the "unworked" clause.

I actually really like that limitation to the spell. In fact, I'm kind of befuddled as to why that was never addressed in any earlier edition. Separately, there's the also the detail in the 2nd paragraph about collapsing the roofs of underworld tunnels and causing 8d6 damage cave-ins (save for half); this seems very reminiscent of Doug Niles' rule in the 1E Dungeoneer's Survival Guide, but it's unclear if the rule was imported directly from there. At any rate, I'm not sure I like that so much.

Gygaxian Perspective

Let me expand upon that issue in its own section. What would Gygax's intent be regarding transmute rock to mud against stone fortifications? For starters, the overwhelming evidence is that Gygax conceives of the standard D&D game world as being essentially quasi-medieval in nature, and I support that. Radical changes in the game world society cannot be inferred from one or two whacked-out spell descriptions; rather, if a certain magic effect inherently contradicts the medieval world situation, then something about the spell needs to be adjusted to comply with that initial assumed milieu. (OD&D Vol-1, p. 5: "expansion is recommended only at such time as the possibilities in the medieval aspect have been thoroughly explored").

For example: Gygax's second novel, Greyhawk Adventures: Artifact of Evil opens with a major assault on a concentric stone castle at the edge of the Pomarj (a region overrun by evil humanoids; setting of the A1-4 Slave Lords series of modules). In addition to legions of men and monsters, fairly large contingents of spell-casters are engaged on both sides of the battle. From the first paragraph of the book:

The starless night was suddenly bright with globes of glowing light, radiance that shed betraying illumination behind the lines of besiegers outside the fortress... The magic missiles, blazing fireballs, and crackling bolts of lightning were far worse. Bodies were tossed high by roaring blasts; wheeled shelters were split and broken by the flashing strokes of electricity while metal-clad men-at-arms behind them became charred corpses. Varicolored darts sped unerringly into hapless targets who screamed and died. Torrents of flame erupted from the sky to set siege towers blazing, giant torches that added a hellish light to the scene, while raging fires swept over the advancing lines or made curtains of flame that seared their flesh.

Other magic effects that are thrown from either side over the course of the next few pages: summon elementals (fire), Evard's black tentacles, chain lightning, cone of cold (?), darkness, moonbeam, precipitation, cloudburst, summon elemental (water), summon elemental (earth), major illusions, etc.

That's a lot of high-level magic. But one thing that doesn't happen: at no point are the walls of the castle transmuted from rock to mud. That's hard to interpret if Gygax thinks the effect is feasible, in the context of such an enormous force of high-level spell-casters. Likewise: Note that the 1E DMG had a table including about 10 magical effects that would cause structural point damage against constructions in a siege (p. 109), but transmute rock to mud was not among them.

More evidence from the old Gygax Q&A thread on ENWorld (dates uncertain): One poster proposes a plan of action in regards to the famed Temple of Elemental Evil: "One mage with a Rock to Mud could take out the whole place..." (going on for about 9 paragraphs about the detail of volume of mud involved , effect on lower levels, etc.). Here's Gygax's response:

My players know better than to try something sure to incur wrath >:-)

Such tactics are a matter for the DM to manage, and as one here is how I would handle an attempt of this sort.

"Sorry, Flubspell, but your Rock to Mud casting seems to fizzle out when it contacts the stonework of the temple. golly, I guess the builders must have imbued it with some fort of protection from this sort of assault on its integrity..."

"Oh, by the by, it seems that you are now turning a ghastly gray color. It seems as if yout attempt has invoked a curse of some sort, as you feel quite weak and not at all well..."

I'd use the same sort of response if someone tried that with any important campaign setting. To stop the rules lawyers from their shrill protests I's write up a few spells to cover constructions--anti-disintigration, anti-rock to mud, etc. Also a few retributive spells to be activated and aimed unerringly at any spell caster attempting to bring down a stricture by that sort or obvious and predicatble tactic. Just because such spells are not included in the standard roster doesn't mean they don't exist.

Cheers,

Gary

So as expressed earlier, Gygax does not look at a spell like transmute rock to mud and deduce that medieval stone fortifications are passé in the D&D campaign world. Rather, he takes as a given that castles exist in the game (and dungeons!) and instead extrapolates that there must be a rather wide array of protection and "retributive" spells commonly used upon such constructions. Not just for the Temple of Elemental Evil itself, but explicitly "any important campaign setting", which I would argue would include any fortification set down by the DM in the campaign world.

I think all of that comes from an honorable instinct. The one thing on which I tend to differ with Gygax is that the implied array of defensive spells (outside any rulebook) seems to commit the offense of "multiplying entities beyond necessity". I would prefer a more minimalist solution, by simply adjusting the originally offending spell a slight bit -- and I think (somewhat unusually) that the 3rd Ed. limitation to "natural, uncut or unworked rock" is a pretty elegant piece of editorial wisdom. I even take an extra step in my own Book of Spells and further prohibit use of the spell against any "load-bearing" stone, so as to cut out the tunnel (and dungeon) cave-in usage.

May I also point out that Gygax's sarcastic reference to the transmuter "Flubspell" here (sometime in the early 2000's), is reminiscent of a character identified as "Flubbit the Wizard" back in OD&D Sup-I (1976; see the magic mouth spell description on p. 22). 

Conclusion 

Which form of the spell is your favorite? Did you actually prefer more chaos in your world, such that that transmute rock to mud works on fortifications and makes them effectively a useless piece of technology?