Come to think of it, there is one.
The adventure "Diplomacy by Christopher Wissel in
Dungeon #144 (March 2007) has a Tertian Modron, so here's the comparison:
AD&D Stats
TERTIAN
| CLIMATE/TERRAIN: | Mechanus |
| FREQUENCY: | Very rare |
| ORGANIZATION: | Hierarchy |
| ACTIVITY CYCLE: | Any |
| DIET: | Special |
| INTELLIGENCE: | Supra-genius |
| TREASURE: | Nil |
| ALIGNMENT: | Lawful neutral |
| NO. APPEARING: | 1 (of 9) |
| ARMOR CLASS: | –5 |
| MOVEMENT: | 12 |
| HIT DICE: | 17+17 |
| THAC0: | 3 |
| NO. OF ATTACKS: | 3 |
| DAMAGE/ATTACK: | 5d8 (×3) |
| SPECIAL ATTACKS: | See below |
| SPECIAL DEFENSES: | See below |
| MAGIC RESISTANCE: | 80% |
| SIZE: | L |
| MORALE: | Fearless (20) |
| XP VALUE: | 18,000 |
Didn't bother copying the special abilities as they're pretty much the same as the 3.0 version
3.0 Stats
TERTIAN (Hierarch Modron)
Large Outsider
Hit Dice: 17d8+85 (161 hp)
Initiative: +7
Speed: 30 ft.
Armor Class: 31 (–1 size, +3 Dex, +19 natural)
Attacks: 2 slams +22 melee, tail slap +20 melee
Damage: Slam 2d8+6, tail slap 2d8+3
Space/Reach: 5 ft. by 5ft./10 ft.
Special Attacks: Spell-like abilities, spells, stun
Special Qualities: Damage reduction 40/+4, modron traits, outsider traits, psionics immunity, resistances, SR 31, telepathy
Saves: Fort +15, Ref +13, Will +16
Abilities: Str 22, Dex 17, Con 20, Int 20, Wis 22, Cha 22
Skills: Concentration +24, Diplomacy +25, Gather Information +25, Hide+13, Intuit Direction +16, Knowledge (arcana) +15, Knowledge (architecture and engineering) +15, Knowledge (local) +15, Knowledge (planes) +17, Listen +24,Scry +20, Search +21, Sense Motive +25, Spellcraft +22, Spot +25
Feats: Alertness, Blind-Fight, Improved Initiative, Multiattack, Spell Penetration
Climate/Terrain: Any land
Organization: Solitary
Challenge Rating: 16
Treasure: None
Alignment: Always lawful neutral
Advancement: 18–51 HD (Large)
Combat
A tertian attacks with its spells, spell-like abilities, fists, and tail in combat.
Spell-Like Abilities: At will—clairaudience/clairvoyance, command, dimension door, teleport without error (self plus 50 pounds of objects only), and wall of force. These abilities are as the spells cast by a 20th-level sorcerer (save DC 16 + spell level).
Spells: A tertian casts divine spells as a 20th-level cleric (save DC 16 + spell level) and arcane spells as a 20th-level sorcerer (DC 16 +spell level). It has access to the domains of Law, Protection, and War.
Stun (Ex): Any creature hit by the tertian’s tail slap must make a successful Fortitude save (DC 24) or be stunned for 3d4 rounds.
Modron Traits: Immune to mind-influencing effects; not subject to subdual damage, ability damage, ability drain, or energy drain; not subject to critical hits.
Outsider Traits: Darkvision 60 ft.; cannot be raised or resurrected.
Psionics Immunity (Ex): Immune to all psionic attacks.
Resistances (Ex): Acid, cold, and fire resistance 10. 17
Telepathy (Su): A tertian can communicate telepathically with any creature within 405 miles that has a language.
3.5 Stats
Tertian modron
CR 19
LN Large construct (extraplanar, lawful)
Web enhancement for Manual of the Planes (updated to 3.5)
Init 18 (fixed); Senses darkvision 60 ft.; Listen +38, Spot +38
Languages Modron; telepathy 405 miles |
AC 39, touch 14, flat-footed 34
hp 199 (26 HD); DR 15/adamantine and chaotic
Immune construct traits
Resist acid 10, cold 10, fire 10; SR 31
Fort +10, Ref +13, Will +17 |
Spd 30 ft.
Melee* tail slap +30 (4d6+22 plus stunning blow) and
2 slams +27 (2d6+11)
Space 10 ft.; Reach 10 ft.
Base Atk +19; Grp +36
Atk Options Cleave, Power Attack
Spells Known (CL 19th; +23 ranged touch)
9th (4/day)—gate, time stop
8th (7/day)—demand (DC 26), dimensional lock, shield of law (DC 26)
7th (7/day)—dictum, greater scrying (DC 25), plane shift (DC 25)
6th (7/day)—antimagic field, greater dispel magic, symbol of persuasion (DC 24)
5th (7/day)—dismissal, dispel chaos, hold monster (DC 23), sending
4th (8/day)—dimensional anchor, charm monster (DC 22), freedom of movement, order's wrath (DC 22)
3rd (8/day)—dispel magic, fly, haste, protection from energy
2nd (8/day)—detect thoughts (DC 20), hold person (DC 20), calm emotions (DC 20), levitate, locate object
1st (8/day)—cure light wounds, divine favor, mage armor, shield, protection from chaos
0 (6/day)—arcane mark, cure minor wounds, detect magic, ghost sound (DC 17), mage hand, mending, open/close, prestidigitation, read magic
Spell-Like Abilities (CL 19th)
At-will—clairaudience/clairvoyance, command (DC 19), greater teleport (self plus 50 pounds of objects only), wall of force
3/day—quickened wall of force
* 5-point Power Attack |
Abilities Str 36, Dex 21, Con —, Int 30, Wis 28, Cha 26
SQ fixed initiative
Feats Cleave, Empower Spell, Extend Spell, Great Fortitude, Improved Toughness (+1 hp/HD), Maximize Spell, Multiattack, Power Attack, Quicken Spell-Like Ability (wall of force)
Skills Concentration +29, Diplomacy +31. Gather Information +37, Intimidate +37, Knowledge (arcana) +39, Knowledge (history) +39, Knowledge (the planes) +39, Listen +38, Search +39, Sense Motive +38, Spellcraft +43, Spot +38 |
Fixed Initiative (Ex) Modrons have a limited form of prescience that governs when they take action in a conflict, and they never waver from this schedule. As a result, a modron's initiative check is always equal to half its Hit Dice, modified by its Dexterity. When combat begins, a modron uses this number as its initiative—it never rolls an initiative check.
Spells A tertian modron casts spells as a 19th-level sorcerer, and can also choose spells from the cleric list and from the Law domain for its list of spells known. The cleric spells and domain spells are considered arcane spells for a tertian modron, meaning the creature does not need a divine focus to cast them.
Stunning Blow (Ex) A creature struck by a tertian’s tail slam must make a DC 36 Fortitude save or be stunned for 1d4 rounds. The save DC is Strength-based. |
Okay, the 3.5 Tertian has 26 HD, which is pretty close to 50% higher than the 17 HD of the AD&D and 3.0 versions. Its HP of 199 is about 20% more than the 166 hp of a 3.0 Decaton.
So 15 HD for the Decaton as suggested earlier might work, for either 15d10+20 (102 hp) or 15d10+35 (117 hp) depending on whether it has Improved Toughness. That's 156.9% or 180% of the 3.0 Decaton's 10d8+20 (65 hp).
For the abilities, consider the following:
| Type | 3.0 Abilities | 3.5 Abilities |
|---|
| Pentadrone | Str 18, Dex 16, Con 14, Int 12, Wis 12, Cha 12 | Str 22, Dex 12, Con —, Int 17, Wis 16, Cha 16 |
| Decaton | Str 11, Dex 15, Con 15, Int 14, Wis 14, Cha 14 | Str ?, Dex ?, Con?, Int ?, Wis ?, Cha ? |
| Tertian | Str 22, Dex 17, Con 20, Int 20, Wis 22, Cha 22 | Str 36, Dex 21, Con —, Int 30, Wis 28, Cha 26 |
Not sure why the 3.5 Pentadrone has Dex 12 while the 3.0 one is Dex 17. Seems a bit backwards.
From Pentadrone to Terian is eight "promotions" with Decaton on the first rung. The procession is Pentadrone >1> Decaton >2> Nonaton >3> Octon >4> Septon >5> Hexton >6> Quinton >7> Quarton >8> Tertian.
If it was even and orderly, that'd mean each step is one-eighth more than the one before it so some of a Decaton's stats are 112.5% of a Pentadrone.
However, there is a big jump from Base Modron to Hierarch Modron as indicated by their Hit Dice, with an AD&D Decaton's 10+10 HD being twice a Pentadrone's 5+5 HD.
If we follow that with the 3.5 Pentadrone's 6 HD then the Decaton would have 12 HD like you suggested, which suggests each Hierarch rank has 2 Hit Dice more than the previous one since the Tertian (26 HD) has fourteen more Hit Dice than a Decaton and is seven ranks higher.
A neat progression like that seems rather Modron like.
With Improved Toughness that comes to Hit Dice 12d10+32 (98).
A 3.0 Decaton's saves are Fort +9, Ref +9, Will +9. The Fort save is relatively unimportant for a construct due to its physical immunities, but I think we need the Ref and Will saves to be roughly on par (note the 3.0 Tertian's Fort +15, Ref +13, Will +16 and the 3.5's Fort +10, Ref +13, Will +17).
To get Ref +9 and Will +9 from a 12 HD constructs +4 base saves it'd need either 20-21 in Dex and Wisdom or 16-17 Dex and Wis with +2 from a save-boosting feat.
Alas, we don't have feats to spare so that seems difficult, plus if it only has 12 HD that aggravates the comparative Skill Point shortage I mentioned earlier.
Speaking of which, how does the 3E Tertian stand on SPs?
The 3.5 version has 26 Construct Levels and Int 30 for 348 SPs.
The 3.0 version has 17 Outsider Levels and Int 20 for 260 SPs.
Note the 3.0 Tertian has twice the 130 SPs of a 3.0 Decaton (10 Outsider Levels and Int 14). If the 3.5 Decaton has around have the SPs of the 3.5 Tertian, which is 174 SPs, it'd need either way more Construct levels or a way higher Intelligence than the 3.5 version (or some combination of the two).
For example (mostly extreme ones):
12 Construct Levels => Int 30-31 for 180 SPs.
15 Construct Levels => Int 26-27 for 180 SPs.
26 Construct Levels => Int 18-19 for 174 SPs.
Yeesh! I think we'd better keep the SPs close to the 130 of the 3.0 version.
We could go back to 15 Construct Levels and Int 20 for 126 SPs. Wisdom 18 for Will +9 and probably Charisma 18. I could go for Dexterity 19 for Ref +9 but would consider Dex 15 like the 3.0 version and adding Lightning Reflexes for the Reflex save.
Hmm, the 3.0 Tertian has mental ability numbers 6 or 8 higher than the 3.0 Decaton (Int 20 & Wis 22 versus 14 for the Decaton). Using a similar relationship with the 3.5 Tertian's Int 30, Wis 28, Cha 26 could give us, say Int 22, Wis 20, Cha 20. That's a healthy 144 SPs with 15 Construct HD and Will +10.
As for Dexterity, the 3.0 Tertian has 2 higher Dex than the Decaton, which is the Dex 19 mentioned as providing Ref +9.
That just leaves Strength. I'm still inclined to keep this relatively modest. The original only did 1d4 damage with each of its attacks, after all.
Don't think I'd go over Strength 15.
So Str 15, Dex 19, Con —, Int 22, Wis 20, Cha 20 and HD 15?
