* aside from treasure type, which should really be dealt with separately, since treasure is going to be an unholy mess.
Number Appearing jumps around quite a bit, but there are a couple notably consistent features.
- Humans and other intelligent creatures that tend to form communities are found in multiples of d10 x10, with smaller communal creatures being more numerous (4d10 x10) and human groups being right at 3d10 x10.
- Really powerful creatures roll only 1 die (type varies) for number appearing. The more powerful the creature, the smaller the die type.
- Both summoned otherworldly creatures and powerful nuisances (oozes) are listed as appearing singly.
- Other creatures, particularly pack predators, roll more than one die, but don't have a multiplier like communal creatures.
Notes for monster types will make it clear that otherworldly creatures and oozes tend not to appear in groups except under special circumstances.
Add 1d6 (or +1 for small groups) for weaker/smaller creatures, subtract 1d6 (or -1 for small groups) for stronger creatures.
- tribe/herd/flock: 10x 5d6
- pack: 3d6
- small group/family: 1d6
% In Lair is much more unpredictable. It seems to be pretty random, although definitely those monsters without a treasure type have no "% In Lair" entry, even if they would logically have a lair. Only one entry has a 100% value: nixies. We might argue that this is because they require a very unique environment, generalizing that as a rule. Most of the "tribe/herd/flock" creatures are at 50%, except elves (25%) and men (15%). Because of the high randomness, I'm inclined to convert the numbers to situation rolls and get rid of the percentages. We could link different behavior types (settled, nomadic) to different situation types and use just a couple modifiers.
If adventurers stumble upon a monster lair in the wilderness, there's a chance that the occupant isn't present. Make a situation roll appropriate for the type of lair:Not exact, and a significant change, but I think most GMs ignore or change the way this rule works, anyways.
Add +1 to the roll for larger groups or weaker creatures; subtract -1 for restless creatures. Use Avoid Danger for powerful, brooding monsters. Don't roll for creatures which constantly roam over a large area (they will never be in a lair) or for those that require unique environments or are placed as permanent guardians.
- settlement -- Change Situation
- camp, den -- Avoid Accident
Edit: I got the situation rolls in the wrong order. If you stumble into a town or dwarven outpost, you will almost always run into occupants; you are rolling to change that situation. Similarly, if you stumble into a nomad camp, they are out hunting often enough that there's a greater chance they won't be "at home" when you come calling; you are rolling to avoid accidentally running into them.