I’m going to cut to the chase: I went through the original AD&D Monster Manual and analyzed each monster in a spreadsheet. My first pass was to try to get guidelines for treasure, but then I looked at other things not in Dungeon Fantasy: number appearing and percent in lair.
The point of doing all this was to get guidelines for placing monsters in the game world and giving them appropriate resources. And I made some guidelines.
But first, some notes about these findings.
Treasure: Do you know the biggest determiner as to whether or not a monster has treasure? Intelligence. The monsters that lack treasure have an average Int of 2.1, while those that have monetary and semi-monetary (gems and jewelry) treasure have an average Int of 9.4. The rich monsters only have 4 more hit points (34.4 to 30.4). (Incidentally, hit points account for about 81% of the variance in experience points. If you square monster HP, it's near monster XP. Obviously, there will be exceptions.) They come in bigger groups too (21.1 to 6.3), but we’ll get to that in a bit. Hence, if you’re using Combat Effectiveness Rating to place treasure, you’re going to have issues like goblins, who are sapient and tool-using, having less treasure than a Tyrannosaurus rex unless you override this or make a formula (like IQ squared divided by 100 giving a relative weight).
For those monsters with not much treasure, you'll want to pick whether the loot is a few high-worth items like gems or jewelry or many copper and silver coins. For humanoids, I'd go with the latter. The first is for dumb monsters like shiny gems and kill to get them. Big hoards will have both. In D&D, this is a big deal, since GP found means XP earned, and being unable to take some loot means forsaking its XP. In Dungeon Fantasy, you only need enough for a week’s Cost of Living, paying off your backers, healing up, and topping off your power items.
I didn’t try to get an any estimate of how often the rolls for each treasure type yields nothing, though I did allow for that happening when you roll for low-treasure monsters. Nothing happens more often with magic items. However, it’s anticlimactic to have “You get nothing! Good day, sir!” when you’ve beaten Demogorgon, so I’m shunning that.
Something I didn't cover but is worth noting is that in OD&D and AD&D, each magic item had a chance (25% and 10%, respectively) to be a map instead. Make it lead to $8d×1,000 and 1d-2 magic items or something; these treasure hoards were often big. Yes, I know damn well that the roll of map (I'd have it on a 2-3 on 2d) is a pain in the ass, but they often led to big hoards. Have a suitably tough monster that otherwise doesn't have much treasure near it, like a mutant dire animal.
Number appearing: GURPS has mentality traits that reflect how often the species likes to be around others; this is the whole sliding scale of Loner and Chummy. For those species that like others, I’d do something like adding half again to the numbers if Congenial, twofold if Chummy, and fourfold if Gregarious. For those who don’t like others, I’d have them be one-fourth less if Uncongenial, half if Loner (15), one-fourth if Loner (12), and one only for Loner (9) and Loner (6). This is pretty much pulled right out of my ass; take what you will of it.
Likewise, AD&D has three sizes. You might want to have a more gradual scale of number appearing, going down more slowly as they get bigger or going up more slowly as they get smaller.
The numbers below are for number of fighters in lair. The humanoids will have a like number each of spouses and children. I’ll leave out the nitty gritty of orc breeding and Gygax's sexism. Extrapolating from the D&D Expert Set (p. X27) and Dave Arneson’s and Richard Snider’s First Fantasy Campaign, the average number of monsters encountered out of lair is one fifth the number in lair. So, if your goblin lair has 145 goblins in it, the average number in a non-lair encounter will be 29, which comes out to 8d+1. And when the murder hoboes reach the goblin lair, two squads, or 16d+2, will be out prowling. Per Arneson, each squad will be 1d miles away, and will likely hasten back home once the smoke signals go up that their home is under attack.
In lair: This doesn't vary as predictably as I had hoped, leaving aside Alexander Macris's recommendations in ACKS Lairs & Encounters (which is a great resource I keep meaning to review). For some monsters, like liches, dragons, and demon lords, it's clear that being smarter keeps them in their lair to guard their treasure.
Figuring whether or not you encounter a monster in its lair will go like this. You roll 1d and subtract a number. If the resulting number is negative, then it’s in its lair when you find it. Otherwise, the number represents the number of hexes away (5- or 6-mile hexes) its lair is. On a roll of 0, that means its lair is in this hex, but not where you ran into the monster. (For bigger hexes, its lair is always in the hex, though you can take fivefold this number to be how many miles away its lair is.) On average, the roll is 1d-3, or a 33% in lair chance.
For those who don't know—and don't feel bad if you don't, as it took me years to get this—the badly-explained % In Lair (or % In Liar, if you will) works with random encounters like this. First, you roll to see if the players have an encounter. Then, you roll to see which monster it is on whatever table, then roll how many there will be in the lair. Then, roll % In Lair. If you roll under this number, then the players have stumbled on the monster's lair, and there will be bigger numbers and treasure. If you roll higher than that number, the players have only met a squad of them outside the lair, and if they want to get the treasure beyond pocket change, they'll have to find the lair, so will need to make Tracking rolls. (Courtney Campbell has a summary of what is in the First Fantasy Campaign here.)
One last note: I left out leaders from my analysis to keep things simple. At the easiest, each band of intelligent humanoids will have some kind of leader, who will be tougher than his mooks. Put them with the others at your will; my numbers for those appearing do not include them.
For all these reasons, I highly recommend making lairs of monsters before you roll for your random outdoor encounters for a session. This is what Macris calls a dynamic lair. I have about 40 for when my players run into a truly random encounter.
(One-upping this, Arneson rolled his random encounters before the session started.)
Oh, one last thing before I publish this: smart monsters who have lots of treasure but don't have big numbers (dragons, demon lords, liches) will often be in their lairs. This is one of the few big takeaways I get for this stat.
Making encounter tables: These are looser guidelines than everything else here. They might be better off as observations. Some of them don't come from the Monster Manual.
- Monsters with big hoards are rarer than poor monsters. Wealth is only valuable if it’s scarce.
- Tougher monsters (high CER) are rarer than weaker monsters. In the wild, the predator is less numerous than its prey, as wolves outnumbering deer would lead to starving wolves.
- Monsters with a high lair chance (like 1d-5) will be rarer than ones who are seldom in a lair (like 1d-2). In this case, think of what it means to encounter a monster—you run into it. If a monster stays in its lair all the time, how will you run into it? There’s a reason liches and great wyrm dragons stay inside, and it’s to keep others from finding them. Besides, having a mindwarper and a minotaur have the same frequency on a table means you’ll be stumbling onto more mindwarper lairs. Shades of the quantum ogre come into play if you don’t adjust for this.
- Monsters should fit their environment. Without some tweaking, the desert monsters in Mirror of the Fire Demon would be odd in the Frozen North.
- If a monster is a bait-and-switch monster, you need to have examples of the actual version of the monster to pull off the bait-and-switch. There's a reason the four lycanthropes in Monsters & Treasure are all apex predators and not bunnies, since running into a tiger or wolf is almost always filled with danger, while a rabbit wouldn't draw anything more than, "Look at the cute widdwe bunny wabbit! I will name him 'George' and love him and squeeze him and pet him and pat him!"
Think about writing lairs before the game, and having them on hand for when you roll that encounter. All this rolling takes time, and it will take a bit to figure out the composition of treasure hoards.
Animal: If an animal is under SM 0, there will be 3d+1 of them. For animals of SM 0, there will be 3d-1 of them, and for bigger animals, there will be 2d-1 of them. These are going to vary wildly. I’m not going to try to mimic the social organization of real-world animals.
Animals will have no loot unless they are underwater animals. For those, if they have loot, they will have $6d×1,000 and 1d-5 magic items. I’d only have animals who are actually dangerous in some way have treasure, like sharks and whales and giant piranha swarms, and the loot is leftover from their prey.
For animals, the in-lair roll is 1d-3. If an animal doesn’t have loot, you can skip this, or make the roll 1d-2 for those animals to represent stumbling upon its nest.
Construct: There can be only one. And it will have no loot. Whatever owns it may have loot; the construct itself may count as that. And it’s always in its lair.
Demon: If the demon is under both SM +1 and IQ 10, there will be 3d+1 of them; they will tend to be the minions of evil. For those under SM +1 and over IQ 9, there will be 2d-1 of them. For those bigger than SM 0 but having less than IQ 13, there will be 1d-1 of them. Lastly, for those bigger than SM 0 and smarter than IQ 12, there will be one when encountered; these are your demon lords.
The dumb demons will have no loot. For those bigger than SM -1 and smarter than IQ 8, they will have $4d×1,000 loot and 1d-4 magic items. For those bigger than SM 0 and smarter than IQ 12, they will have $14d×1,000 loot and 2d magic items. Demon lords are loaded.
The in-lair roll is 1d-3, or 1d-4 for demon lords. Demons with treasure tend to stay by it for some reason. (Well, we all know the reason, which is that they don’t want delvers to steal their treasure. I mean, duh.)
Dire Animal: Those dire animals under SM +1 will come in groups of 2d+1, and those bigger than SM 0 will come in groups of 1d. Only those dire animals smarter than IQ 3 or bigger than SM +3 will have treasure: $(2d-4)×1,000 loot and 1d-4 magic items. Their in-lair roll is 1d-3.
Divine Servitor: See demons. However, those in the service of their god will have no treasure. Evil has more fun.
Elder Thing: Elder things will come in gangs of 1d-1. Those smarter than IQ 9 and not summoned will have $4d×1,000 loot and 1d-1 magic items. Their in-lair roll is 1d-4.
Elemental: Much like constructs, they come in packs of one and have no loot. Since they’re summoned, they’re obviously not in their lairs.
Faerie: For those smaller than SM 0, they come in groups of 8d, while those of SM 0 or bigger come in groups of 1d. You truly might want some gradually-increasing grades between these, like 2d at SM -1, 4d at SM -2, 8d at SM -3 and so on. Nixies are driving up this number, regardless. They all have treasure of $4d×1,000 loot and 1d-3 magic items. The in-lair roll is 1d-3.
Giant Animal: Mostly, they are like normal animals. A single change is that land giant animals can have treasure. I’d give those bigger than SM +3 and smarter than IQ 3 $(2d-4)×1,000 in loot and 1d-4 magic items. Their in-lair roll stays 1d-3.
Hybrid: Like I said last time, treat them as dire animals. AD&D has no class like this, but for these purposes, they’re more or less the same thing as dire animals, being man-eating mutants who aren’t smart enough to be tool-users.
Mundane: This is pretty much three classes of monster. The first is what D&D 3.5e calls Humanoids, and are your humans, dwarves, and orcs, among others. For them, have 2d×20 of those smaller than SM 0, 2d×10 of those of SM 0 and dumber than IQ 9, 4d×10 for those of SM 0 and smarter than IQ 8, 2d-1 of those bigger than SM 0 and dumber than IQ 10, and 1d for those bigger SM 0 and smarter than IQ 9. For treasure, those under IQ 10 will have $3d×1,000 loot and 1d-5 magic items. Those smarter than IQ 9 will have $8d×1,000 loot and 1d-4 magic items. Their in-lair roll is 1d-3.
The next is a group of which I think as “magical humanoids.” These are Humanoids and Monstrous Humanoids who have odd powers (e.g., medusas, lycanthropes) or have morphologies that deviate quite a bit from the standard humanoid shape (e.g., minotaurs, centaurs). I’d lump proper giants in this group, lumping ogres in with the normal humanoids, though it doesn't matter much. The first group has more treasure, but this group wanders more. Anyways, they come in groups of 5d+1 if smaller than SM +1 and smarter than IQ 9, 2d if smaller than SM +1 and dumber than IQ 10, 2d-1 of those bigger than SM 0 and dumber than IQ 10, and 1d for those bigger SM 0 and smarter than IQ 9. Those dumber than IQ 10 have $(2d-1)×1,000 loot and 1d-5 magic items, while those smarter than IQ 9 have $4d×1,000 loot and 1d-3 magic items. Their in-lair roll is 1d-2; for some reason, they like to wander. I assume their big size (aside from medusas and wererats, they tend to be big) means they have higher dietary requirements and need to hunt more or something. I'd raise the in-lair roll for medusas myself, but that's just me.
Dragons are the third class, aside from a miscellaneous class which is pretty much rock mites so far. Dragons come in groups of 1d-1. Those under IQ 10 have $(10d-3)×1,000 loot and 1d magic items, and have an in-lair check of 1d-3. Smarter ones (IQ 10 or more) have $(2d+2)×10,000 loot and 1d+2 magic items; their in-lair check is 1d-4. A smart dragon doesn’t go flying around announcing its presence, much like demon lords.
Plant: There will be 2d-1 such plants. If they have IQ 6 or higher and are not Bestial, they have $(1d-1)×1,000 loot and 1d-3 magic items. For those plants that can move, their in-lair check is 1d-4. For those plants that cannot move, they are always in their lair.
Slime: Slimes come in groups of 1d-3. If they have IQ 6 or higher and are not Bestial, they have $(1d-1)×1,000 loot and 1d-3 magic items if IQ 6 or higher, much like plants. The few slimes that have treasure have an in-lair roll of 1d-2. Most slimes won’t have a lair; that they’re moving dungeon cleanup is the point.
Spirit: Spirits tend to be lonely and come in packs of one. They have $2d×1,000 loot and 1d-3 magic items if they lack either Slave Mentality or Bestial. Their in-lair roll is 1d-2.
Undead: Those undead that have Slave Mentality or Bestial come in gangs of 3d+1. Liches stay alone; others come in groups of 1d-1 otherwise. The undead who lack Slave Mentality of Bestial have $2d×1,000 in loot and 1d-3 magic items. Liches have $1d×10,000 and 1d-3 magic items. Undead other than liches have an in-lair roll of 1d-3; liches roll 1d-5. Like smart dragons and demon lords, liches do not like to alert others to their presence.