Converting prehistoric animals

[BOZ]

Sounds good. We’ll do the dimey first. Unfortunately, it and all other new conversions will most likely have to wait until the boards are turned back on, which sounds most likely like late Sunday or Monday morning.

 

[BOZ]

X1 (OD&D):

Dimetrodon
Armor Class: 5
Hit Dice: 7
Move: 120’ (40’)
Attacks: 1 bite
Damage: 2-16

No. Appearing: 0 (1-6)
Save As: Fighter: 4
Morale: 8
Treasure Type: V
Alignment: Neutral

A dimetrodon is a sail-backed, meat-eating dinosaur. The "sail" is a comb of long bony spines connected with a skin webbing. The dimetrodon is about 10' long and weighs nearly a ton. Dimetrodons hunt most often in hills and in the drier areas of swamps.



1E MM2:

Dimetrodon

FREQUENCY: Uncommon
NO. APPEARING: 1 or 2
ARMOR CLASS: 4
MOVE: 12"/ /6"
HIT DICE: 3 to 5
% IN LAIR: Nil
TREASURE TYPE: Nil
NO, OF ATTACKS: 1
DAMAGE /ATTACK: 6-16
SPECIAL ATTACKS: Nil
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: Standard
INTELLIGENCE: Non-
ALIGNMENT: Neutral
SIZE: L (9' long)
PSIONIC ABILITY: Nil
Attack/Defense Modes:
Nil/nil
LEVEL/X.P. VALUE:

The “sail-backed” dimetrodon is a fierce predator of the lower Permian period. It is alligator-like and is actually a reptile, not a dinosaur. Its ability to swim is questionable but likely. Its powerful bite makes up for its lack of claw attacks.


FR3:

Dimetrodon

CLIMATE/TERRAIN: Any land
FREQUENCY: Uncommon
ORGANIZATION: Solitary
ACTIVITY CYCLE: Day
DIET: Carnivore
INTELLIGENCE: Non- (0)
TREASURE: Nil
ALIGNMENT: Nil

NO, APPEARING: 1-2
ARMOR CLASS: 4
MOVEMENT: 12/6
HIT DICE: 3 to 5
THACO: 3-4 HD: 17, 5 HD: 15
NO. OF ATTACKS: 1
DAMAGE/ATTACK: 6-15
SPECIAL ATTACKS: Nil
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: Nil
SIZE: L (9’ long)
MORALE: Steady (11)
XP VALUE: 65-175

The sail-backed dimetrodon is a fierce predator and an example of the mammal-like reptiles. Its large fin works like a solar heater, allowing the dimetrodon to heat up to active temperature hours before its prey. Its ability to swim is questionable but likely. The dimetrodon's alligator-like jaws give it a powerful bite (3d4+3 points of damage), more than making up for its lack of claw attacks.


MCA2

Dimetrodon

CLIMATE/TERRAIN: Any land
FREQUENCY: Uncommon
ORGANIZATION: Solitary
ACTIVITY CYCLE: Day
DIET: Carnivore
INTELLIGENCE: Non- (0)
TREASURE: Nil
ALIGNMENT: Neutral

NO, APPEARING: 1-2
ARMOR CLASS: 4
MOVEMENT: 12, Sw 6
HIT DICE: 3 to 5
THACO: 3-4 HD: 17, 5 HD: 15
NO. OF ATTACKS: 1
DAMAGE/ATTACK: 3d4+3
SPECIAL ATTACKS: Nil
SPECIAL DEFENSES: Nil
MAGIC RESISTANCE: Nil
SIZE: L (9’ long)
MORALE: Steady (11)
XP VALUE: 65-175

The sail-backed dimetrodon is a fierce predator and an example of the mammal-like reptiles. Its large fin works like a solar heater, allowing the dimetrodon to heat up to active temperature hours before its prey. Its ability to swim is questionable but likely. The dimetrodon's alligator-like jaws give it a powerful bite (3d4+3 points of damage), more than making up for its lack of claw attacks.


And here is demiurge’s conversion:

Dimetrodon
Large Animal
Hit Dice: 4d8+12 (30 hp)
Initiative: +1
Speed: 30ft, swim 10ft
Armor Class: 14 (-1 size, +1 Dex, +4 natural)
Base Attack/Grapple: +3/+11
Attack: Bite +7 melee (1d8+6)
Full Attack: Bite +7 melee (1d8+6)
Space/Reach: 10ft/5ft
Special Attacks: Improved grab
Special Qualities: Low-light vision
Saves: Fort +7, Ref +5, Will +2
Abilities: Str 19, Dex 12, Con 17, Int 1, Wis 12, Cha 2
Skills: Hide +2*, Move Silently +5*, Spot +3, Swim +12
Feats: Stealthy, Weapon Focus (bite)
Environment: Warm marsh
Organization: Solitary
Challenge Rating: 3
Treasure: None
Alignment: Always neutral
Advancement: 5-8 HD (Large), 9-12 HD (Huge)
Level Adjustment: -

This bulky reptile has a short jaw packed with conical teeth and a long colorful sail runs down the length of its back.

Not actually a dinosaur, the dimetrodon is a primitive reptile with slightly mammalian features.

Dimetrodons average 10 feet in length and about 1 ton in weight. They live in marshes, where they hunt large amphibians and other reptiles. They are competent swimmers, but are slow in the water and swim only to move from one patch of dry land to another.

Combat
Dimetrodons attack from ambush, grabbing hold of their prey and shaking it until it dies. It avoids groups of creatures, preferring to attack ones that are separated from their allies.

Improved Grab (Ex): In order to use this ability, a dimetrodon must hit with a bite attack. If it hits, it can make a grapple check as a free action without provoking an attack of opportunity. If it gets a hold, it deals automatic bite damage each round.

Skills: A dimetrodon gains a +4 racial bonus on all Hide and Move Silently checks made in marshes.
A dimetrodon has a +8 racial bonus on any Swim check to perform a special action or avoid a hazard. It can always choose to take 10 on a Swim check, even if distracted or endangered. It can use the run action while swimming, provided it swims in a straight line.

 

[Shade]

Ummm...I'd say Demiurge nailed it.

 

[BOZ]

gonna have me a look-over.

 

[BOZ]

Issues from past versions:

Is this one strictly solitary? We had solitary or pair from the 1E&2E versions, and groups of 1-6 from OD&D.

The 1E/2E (when they agree, I’ll call that “AD&D” from now on) versions had their swim speed at 6, which would be 20 now.

They had a slightly higher AC in previous versions: 5 in OD&D (15 now) and 4 in AD&D (16 now).

HD: not really an issue, as the AD&D versions gave them 3-5 HD. But the OD&D had 7 HD – such discrepancies between the editions seem common, especially with the prehistoric animals.

Does this have any basis in scientific evidence:

Its large fin works like a solar heater, allowing the dimetrodon to heat up to active temperature hours before its prey.

and if so, does it have any useful game application?

 

[demiurge1138]

The sail fin = heat-sink is the most common theory as to it's purpose, but there isn't really any game purpose to it. I haven't heard any evidence for dimetrodons living in groups, and I still don't think it's entirely appropriate.

Demiurge out.

 

[Zaster]

I agree there probably isn't a game purpose to Dimey's sail. If there were, then you'd expect game mechanics to deal with the thermoregulation of all the basking reptiles. Yuck.

I like Demiurge's conversion, but all the sources I've looked at suggest a weight of about 800 lb. or less. It should still be a Large animal though, so not a big issue.

Here are a few quick search results mentioning size & weight:
http://www.ucmp.berkeley.edu/synapsids/pelycosaurs.html]
http://www.psychosaurus.com/plain/dino/dimetrodon.html
http://yahooligans.yahoo.com/content/science/dinosaurs/dino_card/15.html

I could see bumping the natural AC up by one just to bring AC in line with previous editions.

As for whether it lived in groups or not, I was hoping to find fossil trackway information that would shed some light on that, but no joy. I'd say go with 1-2 just to stick by previous editions.

I don't know what to say about swim speed. There used to be a theory that the sail was used for swimming, but that's been pretty much debunked.

 

[BOZ]

i adjusted the swim speed and AC, and pretty much otherwise left it as demiurge had it. posting in homebrews, let me know if it's kosher.

 

[Zaster]

Looks pretty good from here. Kudos to demiurge.

Natural AC is now greater than a croc but on par with a boar. This sucker's pretty tough.

Though not actually a dinosaur, it is commonly associated with the same era from which such beasts came.

Since Dimey preceded the earliest dinosaurs, it might be best to remove the association with dinos altogether. But from a gaming perspective that might be getting into the realm of nit-picking.

 

[demiurge1138]

Looks pretty good from here. Kudos to demiurge.

Thank you.

Now, what's next? The trachodon/anatosaurus/anatotitan or the plesiosaurus?

Demiurge out.