Converting Rules Cyclopedia Monsters to 5E
by Sheldon MorrisAlright. This is the beginning of a trip through the RC in an effort to convert any monsters to 5E that do not appear in the Monster Manual. I debated with myself about placing this in the Mystara forum since it concerns Mystara-specific content, but in the end I believe this is more about the 5th Edition system than a setting.
What I intend to do is probably post a creature's stat block, followed by notes and comments on how and why I ended up with what I did. From there, I hope to have some discussion on other options and considerations that could improve the creature, be it from a balance or play standpoint.
So, I hope that this sparks some interesting conversations about how to handle Basic D&D monsters in the 5E paradigm. I believe that exploring the behavior and nature of some of these monsters, and how that translates into game mechanics (both in Basic and 5E), is quite interesting.
And, at least this thread may provide people with additional creatures for their 5E games!
The first creature up is in fact the first creature listed in the RC's Monsters section - the Actaeon! I'll start him up in my next post.
[Edited to add my checklist.] This lists the Creature name, what its CR is in basic D&D's Rules Cyclopedia (RC) (according to my formulas), the D&D 5E CR that it has been converted to, and if the conversion has been "done" or I have yet "to do". To shorten the length of the post, the table has three columns across. I hope this is alright to do.
I have now added links where any creature is listed as "done" to bring you directly to the post. Thanks to enderxenocide0 and Tim Baker for the suggestion and how-to!
[Edited for update.] As you can see, the table tags are no longer functioning on the forum (although I have been told people are looking into it, which I am very thankful for). I have removed the table tags so that the links are working again, even though it's still a mess. Remember that there were 3 columns, so there are still 3 creatures listed on most of the lines. And YES, I will (have) return(ed) to this project!
Added - I've tidied this all up so that it's all one column now.. one LONG column though. But at least it's far more usable now.
| Creature | CR (RC) | CR (5E) | Checklist |
| Actaeon (Elk Centaur) | 6 | 6 | done |
| Adaptor | 4 | 4 | done |
| Aerial Servant (Haoou) | 8 | 8 | done |
| Ant, Giant | 2 | 1 | done |
| Ape, Snow | 1 | 1 | done |
| Ape, White | 1 | 1 | done |
| Archon | 17 | - | to do? |
| Athach | 6 | 10 | done |
| Baboon, Rock | 1/2 | 1/2 | done |
| Rock Baboon, Alpha Rock | - | 1 | done |
| Bear, Cave | 3 | 3 | done |
| Beetle, Giant Oil | 1/2 | 1/4 | done |
| Beetle, Giant Tiger | 1 | 1/2 | done |
| Blackball (Deadly Sphere) | 12 | - | to do? |
| Caecilia | 3 | 3 | done |
| Cat, Mountain Lion | 1 | 1/4 | done |
| Crocodile, Large | 2 | 2 | done |
| Devilfish | - | - | to do |
| Djinni (Greater; Pasha) | 9 | - | to do? |
| Dolphin | 1 | 1 | done |
| Dragon Ruler, Pearl | 23 | - | to do? |
| Dragon Ruler, Opal | 27 | - | to do? |
| Dragon Ruler, Diamond | 30 | - | to do? |
| Dragon Ruler, The Great One | 45 | - | to do? |
| Drake, Mandrake | 1 | 1 | done |
| Drake, Wooddrake | 2 | 2 | done |
| Drake, Colddrake | 3 | 3 | done |
| Drake, Elemental | 4 | 4 | done |
| Drolem | 15 | 15 | done |
| Efreeti (Greater; Amir) | 12 | - | to do? |
| Elephant, Prehistoric | 4 | 4 | done |
| Faerie (+ Leader & Elder) | 1/2 | 1/2 | done |
| Ferret, Giant | 1/4 | 1/8 | done |
| Fish, Giant Bass | 1/2 | 1/4 | done |
| Fish, Giant Rockfish | 2 | 2 | done |
| Fish, Giant Sturgeon | 5 | 5 | done |
| Gargantua, Carrion Crawler | 11 | 11 | done |
| Gargantua, Gargoyle | 14 | - | to do |
| Gargantua, Troll | 25 | - | to do |
| Giant, Mountain | - | 11 | done |
| Giant, Sea | - | 10 | done |
| Golem, Wood | 1 | 1 | done |
| Golem, Bone | 3 | 3 | done |
| Golem, Obsidian | 3 | 3 | done |
| Golem, Mud | 4 | 4 | done |
| Golem, Amber | 5 | 5 | done |
| Golem, Bronze | 10 | 10 | done |
| Grab Grass | 1/4 | - | trap? |
| Green Slime | 1/2 | - | trap? |
| Gremlin | 1/2 | 1/2 | done |
| Haunt, Poltergeist | 9 | 2 | in MM |
| Helion | 4 | 4 | done |
| Horde | 1-9 | 2,4,7 | done |
| Hsiao (Guardian Owl) | 2-10 | 2,4,9 | done |
| Hydrax | 3-7 | 5 | done |
| Kryst | 4 | 4 | done |
| Lava Ooze | 3 | 3 | done |
| Leech, Giant | 2 | 2 | done |
| Lizard, Giant Gecko | 1 | 1/2 | done |
| Lizard, Giant Draco | 2 | 1 | done |
| Lizard, Giant Horned Chameleon | 2 | 2 | done |
| Lizard, Giant Tuatara | 2 | 2 | done |
| Locust, Giant | 1/2 | 1/8 | done |
| Lycanthrope, Werebat | 1 | 2 | done |
| Lycanthrope, Werefox | 1 | 2 | done |
| Lycanthrope, Wereshark | 2 | 3 | done |
| Lycanthrope, Wereseal | 2 | 4 | done |
| Lycanthrope, Devil Swine | 4 | 6 | done |
| Malfera | 6 | 6 | done |
| Manscorpion (Warrior & Cleric) | 5,11 | 5,11 | done |
| Manta Ray | 2 | 1 | done |
| Manta Ray, Giant | 5 | 5 | done |
| Mek | 6-8 | 8 | done |
| Metamorph | 2 | - | to do |
| Mujina | 4 | 4 | done |
| Neanderthal (Caveman) | 1/2 | 1/4 | done |
| Nekrozon | 4 | 4 | done |
| Nightshade, Nightcrawler | 20-24 | 22 | done |
| Nightshade, Nightwalker | 16-21 | 19 | done |
| Nightshade, Nightwing | 12-16 | 15 | done |
| Nixie | 1/4 | 1/4 | done |
| Nuckalavee | 8 | 7 | done |
| Phantom, Apparition | 7 | 7 | done |
| Phantom, Shade | 8 | 8 | done |
| Phantom, Vision | 8 | 8 | done |
| Phoenix, Lesser | 9 | 8 | done |
| Phoenix, Greater | 13 | 13 | done |
| Plasm, Lesser | 3 | 3 | done |
| Plasm, Greater | 5 | 6 | done |
| Pterosaur, Small (Pterodactyl) | 1/4 | 0 | done |
| Pterosaur, Large (Pterosaur) | 4 | 1 | done |
| Revener | 5 | 5 | done |
| Rhagodessa | 2 | 2 | done |
| Robber Fly | 1/2 | 1/4 | done |
| Roc, Small | 2 | 2 | done |
| Roc, Large | 4 | 5 | done |
| Salamander, Flame | 4 | 4 | done |
| Salamander, Frost | 5 | 5 | done |
| Shadow | 1 | 1 | done |
| Shark, Bull | 1/2 | 1/2 | done |
| Shark, Mako | 1 | 1 | done |
| Shark, Great White | 3 | 3 | done |
| Shrew, Giant | 1/4 | 1/4 | done |
| Slug, Giant | 5-10 | 5,9 | done |
| Snake, Spitting Cobra | 1/4 | 1/8 | use Poisonous Snake in 5E MM |
| Snake, Giant Racer | 1/2 | 1/4 | use Constrictor Snake in 5E MM |
| Snake, Pit Viper | 1/2 | 1/8 or 2 | use Poisonous Snake or Swarm of Poisonous Snakes in 5E MM |
| Snake, Sea Snake | 1 | 1/4 | use Giant Poisonous Snake in 5E MM |
| Snake, Giant Rattler | 2 | 1/4 | use Giant Poisonous Snake in 5E MM |
| Snake, Rock Python | 2 | 2 | use Giant Constrictor Snake in 5E MM |
| Spectral Hound | 3 | 3 | done |
| Spider, Giant Crab | 1/2 | 1/4 | use Giant Wolf Spider in 5E MM |
| Spider, Giant Black Widow | 1 | 1 | use Giant Spider in 5E MM |
| Spider, Giant Tarantella | 2 | 2 | done |
| Spirit, Druj | 10 | - | to do |
| Spirit, Odic | 11 | - | to do |
| Spirit, Revenant | 12 | - | to do |
| Sporacle | 4 | - | to do |
| Statue, Living Crystal | 1 | - | to do |
| Statue, Living Iron | 2 | - | to do |
| Statue, Living Rock | 2 | - | to do |
| Termite, Swamp | 1/4 | - | to do |
| Termite, Fresh Water | 1/2 | - | to do |
| Termite, Salt Water | 1 | - | to do |
| Thoul | 1 | - | to do |
| Toad, Giant | 1/2 | - | to do |
| Toad, Rock/Cave | 1 | - | to do |
| Undine | 6 | - | to do |
| Whale, Great | 16 | - | to do |
| Whale, Narwhal | 4 | - | to do |
| Yellow Mold | 1/2 | - | to do |