In OSRIC the “dinosaur” category also includes other creatures contemporaneous with or predating the dinosaurs. This means that for the purposes of the OSRIC core rules, prehistoric creatures such as dimetrodon or plesiosaurus are included with “dinosaurs,” even though palaentologists classify them separately.
These rules do include an indication of the rough period in which the dinosaur lived, but dinosaur-infested areas often resemble Sir Arthur Conan Doyle’s The Lost World in that a mishmash of dinosaurs from different times co-exist. Dinosaur areas are only really suitable for relatively high-level play. Portals to such areas can sometimes be found in the nethermost depths of large dungeons.
| Albertosaurus | Allosaurus | Gorgosaurus | Saurophaganax | Tarbosaurus | Tyrannosaurus | |
| Frequency: | Common | Uncommon | Uncommon | Uncommon | Uncommon | Uncommon |
| No. Encountered: | 1 or 4d6 | 1 or 2d8 | 1 or 2d8 | 1 or 2d8 | 1 or 2d6 | 1 or 2d6 |
| Size: | Large | Large | Large | Large | Large | Large |
| Move: | 150 ft | 150 ft | 150 ft | 150 ft | 150 ft | 150 ft |
| Armour Class: | 7 | 6 | 6 | 6 | 5 | 5 |
| Hit Dice: | 8 | 15 | 14 | 16 | 18 | 20 |
| Attacks: | 1 | 1 | 1 | 1 | 1 | 1 |
| Damage: | 2d6 | 3d6 | 3d6 | 3d8 | 3d8 | 3d10 |
| Special Attacks: | None | None | None | None | None | None |
| Special Defences: | None | None | None | None | None | |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | 15% | 15% | 15% | 15% | 15% | 15% |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 5/500+8/hp | 7/1,750+18/hp | 7/1,500+18/hp | 8/2,250+20/hp | 9/3,500+20/hp | 9/5,000+25/hp |
Tyrannosaurids and allosaurids are not related families, but they occupy the same ecological niche: large bipedal carnivores. Allosaurus and saurophaganax are allosaurids, the others are tyrannosaurids. The “Number Encountered” listing allows for two interpretations—they could be solitary predators or pack hunters.
Tyrannosaurus: Cretaceous carnivore, long thought to be the largest land carnivore of the dinosaur age. Gorgosaurus: cretaceous carnivore, smaller than tyrannosaurus. Tarbosaurus: cretaceous carnivore, closely related to tyrannosaurus. Albertosaurus: much smaller cretaceous carnivore. Allosaurus: Jurassic carnivore. Saurophaganax: Jurassic carnivore, may be just a very large allosaurus.
Treasure: None (for all tyrannosaurids and allosaurids).
| Charonosaurus | Edmontosaurus | Hypacrosaurus | Saurolophus | Shantungosaurus | Telmatosaurus | |
| Frequency: | Uncommon | Uncommon | Uncommon | Uncommon | Uncommon | Uncommon |
| No. Encountered: | 2d10 | 2d12 | 5d8 | 4d8 | 3d10 | 6d10 |
| Size: | Large | Large | Large | Large | Large | Large |
| Move: | 150 ft | 150 ft | 150 ft | 150 ft | 150 ft | 150 ft |
| Armour Class: | 7 | 6 | 7 | 7 | 6 | 9 |
| Hit Dice: | 15 | 12 | 9 | 8 | 10 | 4 |
| Attacks: | 1 | 1 | 1 | 1 | 1 | 1 |
| Damage: | 2d8 | 1d12 | 1d6 | 1d8 | 1d10 | 1d6 |
| Special Attacks: | None | None | None | None | None | None |
| Special Defences: | None | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 7/2,000+16/hp | 7/1,200+16/hp | 5/750+10/hp | 5/500+10/hp | 7/1,500+14/hp | 3/75+4/hp |
Herbivores who foraged on all fours and ran on hind legs, there are two main families of the duck-billed dinosaurs known as hadrosaurids: hadrosaurines and lambeosaurines. In game terms there is no difference. Some could be interpreted as semi-amphibious swamp or wetland dwellers, in which case they should have a swimming move, but many, perhaps all, are fully terrestrial. Trachodon and Anatosaurs are now-superseded names for kinds of hadrosaurid.
Edmontosaurus: Cretaceous herbivore, formerly "anatosaurus". Charonosaurus: Cretaceous herbivore. Shantungosaurus: Cretaceous herbivore. Saurolophus: Cretaceous herbivore. Hypacrosaurus: Cretaceous herbivore. Telmatosaurus: Smaller cretaceous herbivore.
Treasure: None (for all hadrosaurids).
| Apatosaurus | Argentinosaurus | Brachiosaurus | Camarasaurus | Cetiosaurus | Diplodocus | |
| Frequency: | Common | Uncommon | Uncommon | Common | Common | Common |
| No. Encountered: | 4d10 | 4d6 | 4d8 | 5d10 | 5d10 | 5d10 |
| Size: | Large | Large | Large | Large | Large | Large |
| Move: | 90 ft | 90 ft | 90 ft | 90 ft | 90 ft | 90 ft |
| Armour Class: | 7 | 7 | 7 | 7 | 7 | 7 |
| Hit Dice: | 30 | 38 | 36 | 18 | 20 | 25 |
| Attacks: | 1 | 1 | 1 | 1 | 1 | 1 |
| Damage: | 1d10 | 1d12 | 1d12 | 1d8 | 1d8 | 1d8 |
| Special Attacks: | Trample | Trample | Trample | Trample | Trample | Trample |
| Special Defences: | None | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 9/2,500+35/hp | 9/2,500+35/hp | 9/2,500+35/hp | 8/2,000+30/hp | 8/2,000+30/hp | 9/2,500+35/hp |
Large quadrupedal herbivores with elephantine bodies and extremely long necks and tails, the sauropods are herd animals. They can bite, but are only really dangerous when they trample. Trampling automatically kills any creature weighing less than a ton in their path—saving throw vs death to avoid. A whole herd stampeding is an impressive sight, best viewed from a safe distance. In fantasy gaming environments sauropods might make good meat animals or beasts of burden.
Apatosaurus: Jurassic herbivore, once called brontosaurus. Diplodocus: Jurassic herbivore, famously long. Brachiosaurus: Jurassic herbivore; long thought to be the largest land dinosaur. Argentinosaurus: Cretaceous herbivore, relatively recently discovered, twice as massive as Brachiosaurus. Camarasaurus: Very common Jurassic herbivore. Cetiosaurus: Jurassic herbivore, earlier relative of the other types
Treasure: None (for all sauropods).
| Centrosaurus | Diceratus | Monoclonius | Pentaceratops | Styracosaurus | Triceratops | |
| Frequency: | Rare | Very Rare | Uncommon | Uncommon | Uncommon | Common |
| No. Encountered: | 1d6 | 1d3 | 1d6 | 10d100 | 1d20 | 1d20 |
| Size: | Large | Large | Large | Large | Large | Large |
| Move: | 120 ft | 120 ft | 120 ft | 120 ft | 120 ft | 120 ft |
| Armour Class: | 3/7 | 3/7 | 4/7 | 3/7 | 2/7 | 3/7 |
| Hit Dice: | 7 | 8 | 8 | 12 | 9 | 16 |
| Attacks: | 1 | 1 | 1 | 1 | 1 | 1 |
| Damage: | 1d8 | 1d10 | 1d8 | 2d6 | 1d10 | 3d6 |
| Special Attacks: | Stomp 3d6 | Stomp 2d6 | Stomp 2d6 | Stomp 4d6 | Stomp 1d10 | Stomp 2d6 |
| Special Defences: | None | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 4/200+4/hp | 5/500+8/hp | 5/400+8/hp | 7/1,000+18/hp | 5/550+8/hp | 8/2,000+20/hp |
Ceratopsians are quadrupedal beasts with horns and bony head armour. They fill the rhinoceros’ ecological niche. Ceratopsians are bad-tempered and prone to charge, making them among the most dangerous of the dinosaur herbivorous species. They were extremely common during the late cretaceous period. The best-known and most common of these creatures, triceratops, was probably about twice as heavy as an elephant. Ceratopsians have two AC scores: one for their armoured heads, the other for their bodies.
If a ceratopsian exceeds its required to hit roll by 4 or more, it has knocked down its target and will stomp on it for the listed extra damage.
Pentaceratops: Cretaceous herbivore, resembling a triceratops with a longer neck-frill and two extra horns protruding from under its eyes. Triceratops: Cretaceous herbivore. Unlike most other ceratopsians it does not seem to have lived in herds. Diceratops: Cretaceous herbivore; extremely rare compared to triceratops. Styracosaurus: Cretaceous herbivore with a distinctive spiky neck-frill; about half the size of triceratops. Monoclonius: Cretaceous herbivore with only one horn. Centrosaurus: Cretaceous herbivore that seems to have lived in very large herds.
Treasure: None (for all ceratopsians).
| Anklyosaurus | Ceratosaurus | Iguanodon | Plateosaurus | Stegosaurus | Velociraptor | |
| Frequency: | Uncommon | Uncommon | Common | Common | Common | Common |
| No. Encountered: | 1d4+1 | 1d4 | 3d6 | 5d4 | 2d4 | 4d4 |
| Size: | Large | Large | Large | Large | Large | Large |
| Move: | 60 ft | 150 ft | 150 ft | 120 ft | 60 ft | 150 ft |
| Armour Class: | 0 | 5 | 4 | 5 | 3 | 6 |
| Hit Dice: | 9 | 8 | 6 | 8 | 10 | 6 |
| Attacks: | 1 | 3 | 3 | 1 | 1 | 1 |
| Damage: | 3d6 | 1d6/1d6/4d4 | 1d3/1d3/2d4 | 1d4 | 2d8 | 3d4 |
| Special Attacks: | None | None | None | None | None | None |
| Special Defences: | None | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 5/750+12/hp | 4/200+6/hp | 5/500+10/hp | 5/475+10/hp | 4/150+6/hp | 6/1,000+12/hp |
A miscellany of other kinds of dinosaur, including some (Anklyosaurus and Stegosaurus) with bony, armoured backs.. Both these creatures have an effective attack by clubbing with their tails. GMs who are fans of Jurassic Park may wish to increase the Velociraptor’s intelligence score to “semi-” or even “low.”
Anklyosaurus: Cretaceous herbivore. Ceratosaurus: Jurassic carnivore. Plateosaurus: Triassic herbivore. Iguanodon: Cretaceous herbivore. Stegosaurus: Jurassic herbivore. Velociraptor: Cretaceous carnivore.
Treasure: None (for all).
| Compsognathus | Deinonychus | Dimetrodon | Dilophosaurus | Euparkeria | Ornitholestes | |
| Frequency: | Common | Uncommon | Uncommon | Uncommon | Uncommon | Common |
| No. Encountered: | 8d4 | 1 or 2d4 | 3d6 | 1d4+1 | 5d8 | 5d4 |
| Size: | Small | Large | Large | Large | Small | Medium |
| Move: | 180 ft | 120 ft | 90 ft | 150 ft | 180 ft | 120 ft |
| Armour Class: | 7 | 6 | 7 | 7 | 9 | 7 |
| Hit Dice: | 1+2 | 5 | 7 | 5 | 1d4hp | 2+3 |
| Attacks: | 1 | 3 | 1 | 1 | 3 | 1 |
| Damage: | 1d6 | 1d3/1d3/2d6 | 1d10 | 3d4 | 1d2/1d2/1d4 | 1d8 |
| Special Attacks: | None | None | None | None | None | None |
| Special Defences: | None | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 1/15+1/hp | 3/120+5/hp | 4/100+6/hp | 3/120+5/hp | 3/110+5/hp | 2/25+2/hp |
Dimetrodon is technically a synapsid, and is anachronistic here by quite a large number of millions of years, being more separated from Tyrannosaurus in time than 21st century humans are. It had a huge “sail” on its back that may have helped it regulate its temperature. GMs who are fans of Jurassic Park should note the Dilophosaurus presented there was a result of quite a lot of artistic license.
Compsognathus: Jurassic carnivore. Deinonychus: Cretaceous carnivore. Dimetrodon: Permian carnivore. Euparkeria: Triassic carnivore. Ornitholestes: Jurassic carnivore. Dilophosaurus: Jurassic carnivore.
Treasure: None (for all).
| Archelon | Dunkleosteus | Elasmosaurus | Mosasaurus | Nothosaurus | Plesiosaurus | |
| Frequency: | Uncommon | Common | Uncommon | Uncommon | Uncommon | Common |
| No. Encountered: | 1d4 | 1d2 | 1d2 | 1d3 | 1d4 | 1d3 |
| Size: | Large | Large | Large | Large | Large | Large |
| Move: | 150 ft swimming | 210 ft swimming | 150 ft swimming | 150 ft swimming | 90 ft swimming | 150 ft swimming |
| Armour Class: | 3 | 6 | 6 | 6 | 5 | 6 |
| Hit Dice: | 7 | 10 | 16 | 12 | 10 | 20 |
| Attacks: | 1 | 1 | 1 | 1 | 1 | 1 |
| Damage: | 3d4 | 5d4 | 4d8 | 4d8 | 3d6 | 5d4 |
| Special Attacks: | None | Swallow whole | Swallow whole | None | None | None |
| Special Defences: | None | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 5/475+10/hp | 6/1,000+12/hp | 7/2,000+16/hp | 6/1,200+16/hp | 6/1,000+12/hp | 9/5,000+25/hp |
None of these creatures are technically dinosaurs, though all are found in “Lost World” areas. Dunkleosteus can swallow prey whole on a roll of “20” to hit (see “Fish, Giant: Gar”) and actually preceded the dinosaurs by many millions of years. Elasmosaurus can also swallow whole, needing only 18-20 to do so but otherwise as Dunkleosteus. Mosasaurus filled the same ecological niche as sharks. Plesiosaurs may have preferred smaller prey than a man but would still be dangerous. Nothosaurs were amphibious, like huge seals, and could move on land at 60 ft. Archelon was a kind of gigantic turtle.
Dunkleosteus: Formerly known as Dinichthys; Devonian carnivore. Elasmosaurus: Cretaceous carnivore. Mosasaurus: Cretaceous carnivore. Plesiosaurus: Jurassic carnivore. Nothosaurus: Triassic carnivore. Archelon: Cretaceous carnivore.
Treasure: None (for all).
| Archaeopteryx | Pteradon | Pterodactyl | Quetzalcoatlus | Rhamphorynchus | |
| Frequency: | Common | Uncommon | Common | Rare | Uncommon |
| No. Encountered: | 4d12 | 2d10 | 3d12 | 1d2 | 2d12 |
| Size: | Small | Large | Small | Large | Large |
| Move: | 300 ft flying (AA:IV) | 240 ft flying (AA:IV) | 240 ft flying (AA:IV) | 180 ft flying (AA:IV) | 210 ft flying (AA:IV) |
| Armour Class: | 3 | 6 | 6 | 6 | 5 |
| Hit Dice: | 7 | 10 | 16 | 12 | 10 |
| Attacks: | 1 | 1 | 1 | 1 | 1 |
| Damage: | 3d4 | 5d4 | 4d8 | 4d8 | 3d6 |
| Special Attacks: | None | Swallow whole | Swallow whole | None | None |
| Special Defences: | None | None | None | None | None |
| Magic Resistance: | Standard | Standard | Standard | Standard | Standard |
| Lair Probability: | Nil | Nil | Nil | Nil | Nil |
| Intelligence: | Non- | Non- | Non- | Non- | Non- |
| Alignment: | Neutral | Neutral | Neutral | Neutral | Neutral |
| Level/XP: | 5/475+10/hp | 6/1,000+12/hp | 7/2,000+16/hp | 6/1,200+16/hp | 6/1,000+12/hp |
Pterodactyl was really several different kinds of creature, here lumped together. Quetzalcoatlus is assumed to have filled the raptor niche, while the other flying dinosaurs are assumed to have been found in flocks.
Pteranodon: Cretaceous carnivore. Pterodactyl: Jurassic carnivore. Archaeopteryx: Jurassic carnivore; no bigger than an ordinary bird. Quetzalcoatlus: Cretaceous carnivore, huge for a flying creature. Rhamphorhynchus: Jurassic carnivore.
Treasure: None (for all).