A Goblin in the Synthetic Dream Machine

A good human finally asked: “Are there any quick-and-dirty conversion guidelines for porting in B/X or OSE monsters into SDM? HD roughly equate to level, use the baseline stats, and add a special trait/power?”

And I finally found the brain space to answer and not tell myself, “Oh, I’ll do it, but first I must draw and finish and outline this and that and the other.”


I’ll just go with OSE, because I know Gavin better than I know B/X. Um. Also, because I have OSE at home in print and B/X I have nay.

OSE to SDM Monsters

Let’s go step by step …

Standard Attributes Common to Both

  • OSE: Armor Class (AC) = SDM: defense (def) – just use the ascending armor class value as is. Close enough.
  • OSE: Hit Dice (HD) = SDM: level (L) – just use the HD as level. Close enough. Treat monsters with less than one HD as level 0.
  • OSE: hit points (hp) = SDM: life (l) – use the value in parenthesis + the level of the monster. For monsters that can take a lot of damage, double or triple the total. Especially high-level SDM monsters can have huge life scores – this is because SDM’s hero dice mechanic makes critical hits easier to achieve and lets heroes really blast bigger beasties. Of course, no reason the villains couldn’t have villain dice, too … so.
  • OSE: Attacks Usable per Round (Att) = SDM: attack – just give an attack bonus equal to the monster’s level and use the same damage as in OSE. Close enough. For very martial monsters, like hobgoblins, go ahead and bonus them up. +3 should do it. For something supremely terrifying, like an invisible stalker, give it a +6.
  • OSE: Attack Roll (THAC0) = SDM: attack. This and the previous stat element get bundled together. So, you might just write +1 weapon 1d6. If a monster has multiple attacks, you might have +1 weapon 1d6 and +3 bite 1d4+2.
  • OSE: Saving Throw Values (SV) = SDM: ward – saving throw bonuses don’t normally increase in SDM, except through items and traits. Give intelligent or magical monsters a ward score (i.e. a save bonus) equal to half their level, rounded down. Wizardy-type monsters that would be especially resistant against arcane powers and fantastic attacks can get a ward score equal to their level or even higher.
  • OSE: Movement Rate (MV) = SDM: move – a move of 120′ (40′) is normal. You generally don’t even need to mention it. Much slower = very slow, slower (like a dwarf) = slow, faster = fast, much faster = very fast. This comes into play when trying to chase or run away. As a rule of thumb, the referee should give a creature that is one step faster a bonus (like +3 or so), one that is two steps faster a bigger bonus (say, advantage – roll two dice and take the better), and one that is three steps faster doesn’t need to roll. So, a rotting animated corpse (very slow) will only catch a speed elf (very fast) if the speed elf allows it.
  • OSE: Morale Rating (ML) = SDM: morale – just keep it as is. It’s fine.
  • OSE: Alignment (AL) = SDM: ethics – if chaos and law are relevant ethical options in your game, use as is. Otherwise, adapt to fit.
  • OSE: XP Award (XP) = SDM: not directly applicable – SDM suggests giving players 1d6 x 10 xp every time they “brave danger”. In this context, if they fight a much weaker foe that is no challenge, they would earn nothing. However, they would also earn xp for simply observing and fleeing a more powerful foe. Other xp setups are possible.
  • OSE: Number Appearing (NA) = SDM: number – just use as is. It’s fine.
  • OSE: Treasure Type (TT) = SDM: treasure – the easiest option is to just use the OSE treasures as is, converting 1 gp = €1. If you want to be fiddly, you can set up your own random loot tables.

Special Abilities v Traits

OSE lists special abilities for each monster. In SDM, special abilities convert into traits. Convert the one special abilities that will come into play and list them in the special section of the monster description. You can just lump a bunch of abilities into a single trait for simplicity. The following trait might cover most dwarfs and dwarfy-type monsters:

Typical Dwarf. You’re a typical stout, bearded, demihuman. Use dwarfish weapons. Detect construction tricks and room traps and noise through doors (2-in-6). Revel in glowing eyes (60′ infravision).

Appearance, Voice, Wants, Ethics

SDM breaks out 3 more attributes for monsters, for quicker reference (the style is blatantly storrowed from Skerples’ Monster Overhaul):

  • appearance: a few quick adjectives to help the ref describe the monster when the players spot it.
  • voice: how it sounds, but also other hints you might get to the monster before you see it.
  • wants: what it usually wants. Motivation.
  • ethics: how it goes about getting what it wants.

That’s it!


Now Lets Convert an OSE Monster

I’m going to use the goebblin. Totally not a goblin. Here is a goebblin I totally statted up for OSE:

OSE goblin

(obviously this is an OSE goblin, OSE classic fantasy, p. 164)

Converting to SDM, I would come up with something like:

SDM Goblin

Typical small-sized bipedal anthropoform cannon-fodder. Probably engineered without souls or the ability to feel pain, so they’re fine to kill in great numbers. Right?

Number: 2d4 (6d10 in lair).
Level: 0 / Life: 3

Appearance: small, grotesque, pallid, red-eyed.
Voice: Chanting and clicking.
Wants: more, more, more!
Ethics: greedy stupid.

Defense: 13
Move: Normal for a small humanoid.
Morale: 7 (9 with king)
Attack: +1 by weapon or 1d6

Special: Goblin Traits, including 90′ infravision and difficulties in full sunlight. Also, hates dwarfs.

Treasure (roll d6):
(1–3) Treasure Horde C as is tradition, that’s 1,000 gold pieces of archaic form that could be traded for as much cash,
(4–5) they’ve been robbed recently and only have 200 cash worth of naff loot,
(6) A horde of silver coins worth 1,000 cash (8 stones) and the pickled head of a town administrator worth 2,000 cash to the proper Revival Authority.

I might then add a d6 table to describe “this specific goebblin.” Something like …

  1. actually, mutated urchins, not goblins
  2. a savage breed of uplifted rats
  3. skulking skink-derived trogloforms
  4. degenerated nuclearlithics who have forgotten how to propitiate their radiant undergod
  5. green-skinned tuberous vegetable derived carnivores
  6. the traditional fungal lifeform that has caused so much devastation out in the far void.
Dall•E goblin speeder ... spider

Typical goblin spider sourced from Dall•E.


I hope that was helpful! You can get the latest version of the SDM guide book for as little as [some units of currency for membership] over on the stratometaship patreon or for completely free on syntheticdreammachine.com . Old School Essentials is the work of Necrotic Gnome and available here.

The good Gontijo is currently working on a pretty version of the synthetic dream machine guide book and that will be available … later this year. See, I’m learning marketing speak!

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