My OD&D Encounter SOPs

15 May, 2026

I've been running Murdicog's Manse with the Underworld & Wilderness Adventures dungeon encounter tables. These provide nothing aside from the type of monster encountered (numbers are my addition).

I've been gradually compiling a mental "Standard Operating Procedure" for OD&D monsters that fills in some of the gaps left by their printed descriptions. I thought it worth sketching one out for all the entries on the table, tailored to my preferred sci-fantasy "arcade-mode" milieu.¹ Obviously this is nothing novel; I think everyone does something similar when running a dungeon game. But the exercise of writing them all down was fun and prompted me to make some improvements.

The following loose SOPs are conceived with three purposes in mind:

1. To inform how I interpret reaction rolls.
2. To give each monster a gimmick or "thing" that occupies their time in the dungeon (what are they up to if surprised? What do they want?).
3. To provide a reasonably well-defined, learnable way for players to reduce the risk of combat.²

OD&D Monster SOPs

• Kobolds: They are ferocious but good-natured. There is a Kobold King, but he's more of a figurehead. They like limericks -- reciting a clever one will improve their reaction. They also like hunting giant animals, and will respect anyone who has taken a trophy. They are often found hunting or cooking the results of a hunt.
• Skeletons, Zombies, & Ghouls: These lesser undead always mindlessly attack. When not fighting they stand around in a circle and move their jaws as though having a silent conversation.
• Orcs: Orcs live in anticipation of the coming Dark Lord. They train tirelessly so that when He finally manifests they can join together in a mighty Legion of Doom and pour forth from the underworld to lay waste to the World of Men. Thus, when encountered in the dungeon they are usually training, marching in formation, barking orders, sharpening swords, and the like.³ Encounters are seen as excellent training opportunities. They usually attack on low and neutral reactions, but may negotiate or demand a tithe of gold or magic weapon on a high roll. A Lord bearing a Chaotic sword, or at least a Necromancer or Evil Bishop may attempt to assume the mantle of The Dark Lord and command Orcs to do their bidding on a medium or high reaction.
• Goblins & Hobgoblins: Whereas Orcs collectively await the arrival of a Dark Lord, Goblins and Hobgoblins serve the nearest, strongest Goblin King. Wandering goblin parties are always seeking out tribute to take back to their monarch. On a low reaction, they attack, and on a medium or high roll they merely demand that any treasure be surrendered.
• Animals, Wyverns & Cockatrices: Low reactions indicate hunger and/or aggression. They will pick fights they can win, otherwise will try to appear threatening or flee. Arthropods are more likely to be immediately violent. Medium-high rolls indicate curiosity. Animals can be distracted with food for a Turn or two. Mammals and birds can be tamed on a high enough reaction roll by characters of roughly equal or higher HD. When idle, they are browsing, sleeping, or hunting.
• Bandits, Brigands, & NPC Fighters: Human fighters in the dungeon attack on a low reaction, but only shake down or bully on a medium reaction. On high reaction rolls, they are open to teaming up to defeat monsters or acquire treasure. When idle, they are resting, gambling, arguing, or consulting a crude map.
• Gnomes: Generally not hostile -- they play pranks or shout insults on low reaction rolls, and are otherwise willing to trade knowledge of the dungeon for bizarre/arbitrary objects or trinkets (usually teeth). When idle, they murmur quietly among themselves and trace chalk spirals on the walls and floor.
• Robots: Idle robots are in standby mode if Large/Huge. Small robots are encountered performing some menial maintenance task. Roll a random protocol instead of a reaction roll:
  • 1-2 SENTINEL: Remain in place, but attack those who get too close.
  • 3-4 DEFEND: Act to protect the nearest treasure cache, doorway, or unique feature.
  • 5 DETAIN: Attempt to prevent interlopers from leaving the area, and assign detainees a menial task to perform.
  • 6 EXTERMINATE: Self-explanatory.
• NPC Mages: Mages just want magic items and solitude. On a low roll, they will acquire these with force, on medium-to-high they may be willing to exchange services and dungeon lore. In any case, to a Mage, anyone who isn't a Mage of equal or higher level is effectively sub-human. When idle, they ponder tomes and orbs.
• Gnolls: Gnolls are stone-cold killers. They attack on low or medium reactions and rapidly withdraw on a high roll. In either case, the do not negotiate.
• Berserkers: On a low reaction, they're already in a frenzy and attack immediately. Med-high, they might issue a challenge or a wager. They will usually agree to arrange a one-on-one fight if numbers are unequal -- the champion chosen to represent the Berserkers gets +1 HD per three allies rooting for them. They respect high-level fighters (Hero or above) and anyone who can boast well. When idle, they are drinking, telling tall tales, and/or wrestling.
• Cavemen: There are two types: Zoanthropes have voluntarily extinguished their higher-order mental functions -- treat them as animals. Neanderthals are intelligent and want to protect their territory. They can be befriended with gifts of beautiful objects and quality food (i.e. not rations, but rather bottles of wine, wheels of cheese, steaks, loaves of fresh bread, a tasteful charcuterie board).
• Androids: Androids want to infiltrate human society & reorganize it according to the purposes of nefarious interstellar mining cartels. They will attempt to commandeer expeditions to this end, and will shoot those who don't comply with a laser pistol. When idle, they stand perfectly still.
• Wraiths, Wights, Mummies, & Spectres: Higher-level undead are intelligent but have an unquenchable thirst for life-force. They can be briefly pacified by playing music.
• Ogres: Ogres are habituated to taking money and goods from beings weaker than them. They will usually attack on a low reaction or demand tribute on a med-high roll. However, they are quite sensitive about the fact that the world perceives them as uncultured brutes -- if their ego is bolstered by talking to about art, literature, or music they may improve their disposition.
• Anti-cerics: These guys serve a specific evil god (1. Cthulhu, 2. Dagon, 3. Nyarlathotep, 4. Yog-sothoth, 5. Tsathoggua, 6. Thaisaidon). On a low reaction, they will attempt to kidnap a human sacrifice and exsanguinate it before a hideous non-Euclidean altar. On medium-high reactions, they will demand a blasphemous oath or attempt to induct new cult members by asking that one person be offered as a sacrifice. In general, they are always hostile toward Clerics. When idle, they are preaching, praying, or raving.
• Gargoyles: No reaction rolls, per M&T they attack unprovoked 75% of the time. The other 25% they glitch out and simply sit motionless, rolling again after a Turn. They are like the dungeon's white blood cells -- their purpose is to drive out what should not be there.
• Trolls: M&T describes them as "loathsome" and "rubbery". Idle trolls spend their time creeping and skulking, always a bit damp. Unlike Ogres, which have a weird, embittered sense of dignity, Trolls revel in being hated. Trolls usually attack or flee on a low or medium roll. On a high roll, they aren't hungry right now but will seek to be as grotesque and offensive as possible.
• Minotaurs: Per M&T, Minotaurs always attack and never check Morale. Despite being labyrinth-dwellers, they charge in straight lines and get hyper-fixated on what's ahead of them -- thus, you can evade them by moving around corners and in loops.⁴ When idle, they just pace tirelessly up and down the dungeon.
• Mantichores: Mantichores are extremely ferocious. The greatest pleasure you can give a Mantichore is the feeling of your muscles and sinews twisting apart as its claws rake through your fragile body. As such, even on a good reaction roll, there's not much you can do. However, they do like collecting rare books; if you have one and can somehow make it too difficult to claim by force, they may be willing to parlay.
• Thouls: If you are unlucky enough to encounter a Thoul, you can appease it by changing the first letters of your name. You must solemnly announce this: "O Mighty Thoul, I entered the Underworld as Alice Smith, and if you permit me I will leave it as Blice Omith". You must not laugh; it will attack immediately if you laugh. And if word reaches it that elsewhere in the dungeon you have been using your old name, it will stop at nothing to claim its revenge.
• Giants:
  • Hill & Stone: As Bandits.
  • Frost & Fire: As Berserkers.
  • Cloud: Aloof -- they will ignore or brush past encounters on a good roll, otherwise attacking merely to drive their foes away. Always rushing off somewhere, annoyed at being interrupted.
• Dragons: Dragons in their lair want to be left alone to enjoy their treasures. Dragons encountered as wandering monsters have a lordly, untroubled demeanor; the Dungeon is theirs to prowl at leisure. A low reaction roll means that they are going to play with their food before eating it. A medium reaction roll means they are content to merely inspire terror. On a positive reaction roll, they are willing to hold conversation, though they have almost no tolerance for banalities.
• Gorgons: As Gargoyles, they either attack immediately (75% chance) or stand ominously still.
• Chimaerae & Hydrae: As animals, but only a gigantic meal suffices to distract (e.g. giant animal carcass, huge cistern of milk, wagon full of cheese, etc.)
• Vampyres: Wandering Vampyres are usually attempting to feed. They will pick any fight that seems winnable but will attempt to carry off the first foe to fall rather than finishing the battle. They are intelligent and can parley, but are rarely interested in doing so unless those encountered seem like they could provide cultured & sophisticated company.
• Abyssal Archons: When idle, they intone hateful prayers to the Void. Reactions vary by class and level:
  • Clerics below Bishop level may save themselves and their companions from immediate attack by becoming Anti-clerics. Otherwise, no reaction roll is needed -- the Archon will fight without mercy or fear.
  • Parties without Clerics may escape notice if a high reaction is rolled. Otherwise the Archon attacks.
  • Parties with a 9th+ level Fighter or Wizard can parley with the Archon by offering to sell their souls.
  • An Archon can be forced to parley or retreat by speaking its True Name.

The ones I'm just not sure about yet

• Lycanthropes: These are a bit weird in that they could be encountered in either human or animal form. M&T gives a bizarrely detailed breakdown of how to roll up family groups, but little else.
• Basilisks & Medusae: I haven't rolled an encounter with either yet, but it seems like the petrifying gaze makes them ambiently threatening in a way that may not require a SOP.
• White Apes: The white apes of Barsoom are canonically kind of enigmatic and so far I can't quite land on a good "thing" for them to be up to in the dungeon, but I am loath to just lump them in with the animals.

Notes

This was partly inspired by discussing the Realm of Yolmi Bestiary with Scribble recently. The Yolmi monsters all have a very clear "thing" they do when encountered -- though bizarre and silly, it's usually very well-defined. For example, here's an entry I picked at random, "Gamblers":

Gaudily dressed, they invite Adventureers to play with them in obviously crooked games for high stakes. If refused, they will attack 45% of the time. They are also quit adept at passing phony coinage.

The nature of the "crooked games" is vague, but this is otherwise a very well-defined encounter. I know exactly how to run it from three sentences.

Just for fun, here's one more, the "Psii":

Creatures whose breath interacts with the atmosphere to produce a fire-breathing appearance. Their sole purpose in life is to melt coins onto rocks.

A little tougher, but once again it's a very specific thing that this monster wants and does.

Monsters & Treasure provides some guidance along these lines, but it's muddled up with the way most of the monsters were pulled from Chainmail -- many descriptions seem to assume you are encountering the monsters in the wilderness. I think Yolmi is thus a good model for writing monsters in a way that is parsimonious but able to articulate a well-defined encounter guideline.

More broadly, it occurs to me that the basic problem of how to interpret a random encounter (e.g. with 2d6 Goblins) has generated a wide range of solutions:

• The primordial solution is the reaction roll (do the 2d6 Goblins attack or do something else?).
• Trad/neotrad games bypass the issue by writing detailed set-piece encounters and steering players toward them (the 2d6 Goblins have set up an ambush in a highly interactive environment. Also the exact number of Goblins can scale to be a moderately easy challenge for the players.).
• Modern OSR/NSR best practices encourage attaching an activity to wandering encounter table entries, (specify ahead of time that when a Goblin encounter is rolled, they are the Goblins from room 12 and they are looking for their lost pet Centipede. Do a version of this for each dungeon).
• Faction play is as sort of solution -- defining factions lets one constrain an encountered monster's actions to those that are in its faction's interest (the Goblins serve the Goblin King, who is at war with the Trolls in Troll Town).
• Troika! helpfully provides tables of miens to give each monster a unique set of possible reactions (when you encounter Goblins, roll to determine if they are curious, dismissive, preoccupied, gossipy, overly friendly, or paranoid, then improvise accordingly).
• The aforementioned Yolmi style (give all Goblins one thing they do when encountered).

All, I think, are useful tools for the right situation.

#game-design #musings #odnd