Sunday, August 14, 2011

% in Lair

The first book of gaming goodness that I ever owned, months before I ever played in a roleplaying game or really even knew what RPG meant, was the AD&D monster manual , 4th edition, which I have sitting on my lap now.
Many of the stats listed for the beasties seemed cryptic to my 11 year old brain, but perhaps none more so than % in Lair.
I think I, along with a great deal of other gamers  thought this little stat meant “How often the monster is home”, and that seemed pretty useless considering the game was supposed (I thought) to revolve around detailed adventure modules in which the designer choose what room or other a particular monster was in.
% in Lair was thus safely ignored for 30 years.
And then I read this little bit in the FFC.For each encounter, consult the Encounter Matrix for the type of creature that lives at each spot…   The normal chances of the creature being in it's lair are worked out as they normally are. So if Encounter Six has a 30% chance of being found in it's lair, then that percentage is used and the number of creatures encountered will then be any number up to the total number present in the hex.  Again to avoid confusion, you may wish to take the maximum number of creatures that are listed on the Monster Matrix as representative of the population in the hex for each encounter, given a plus or minus 10% to keep the players on their toes.   For each time that the creatures are found in their lairs, there will be a chance that a portion of them are out in the countryside.  To determine this number, assume that 40% of the population is always in the camp and that up to 60% (10 - 6O%) are always outside of the camp.”

Wait, what?  Here Arneson is saying percent in lair is not the chance that a creature will be home – that chance he gives as 40 – 90% after being found “in lair”.  hmmm.  Next I turned to my trusted MM in the hope of clarification and read
“% in Lair indicates the chance of encountering the monster where it domiciles…..”


So % in lair, whatever else it might be, it indicates the chance that players have actually found a lair in a given hex, be it a dungeon, a castle, a thieves den, whatever.  It turns out to be a vital statistic for hexcrawling.

Gygax, in the MM goes on to indicate that it will also mean encountering the monster.   But he seems to be missing something here, the fact that not all monsters are singular and multiple type monster populations – bandits lets say, aren’t always all in the same place at the same time.  It would seem that % in Lair was one of Arnesons stats for hexcrawling that Gary may not have fully used or understood in the same way, leaving out the % not home part.  So when we turn to the FFC and read 40 – 90% of a given population may be out of lair when the lair is encountered – it becomes clear that the "in Lair" stats most important function, one very useful to the hexcrawl Referee is telling what the likelihood of randomly finding a lair is, regardless of how many or who may be home.

For single creatures, it gets interesting. Dragons especially so.  The FFC, gives different chances of a dragon being in its lair depending on type and gender and it does so in two different and conflicting entries – one co authored with Richard Snider, the other, older d6/CHAINMAIL based material.  Arneson and Snider’s AiF  also gives a % chance a dragon is home that differs yet again.  None of these are anything like OD&D’s % in Lair stat for dragons.  So in the case of dragons, it’s easy enough to use one of Arneson’s stats for determining when various types of dragons are in their lair, and OD&D’s % in Lair for when the lair is found itself.

In summary, a % lair roll should be made after a positive encounter roll occurs when adventurers enter an area to see if they have stumbled on the lair or some wandering group outside their lair.  if it is a wandering group, it will be some portion of 10 – 60% (1-6 on a d6, split in half for each roll of 6) of the lair population.  


  1. Great revelation, if I use this, instead of seeking out the dungeons to find treasure, PCs may start seeking out the monsters to find the lairs. Also it helps flesh out a dungeon as a network of lairs.

  2. Not got the LBBs with me at the mo, but was % in Lair chance for men 15% - what if they were the only settlements (besides castles), and it's a good chance that they're dodgy chaps like bandits - gives it even more of a dog-eat-dog post-apoc feel rather than ye merrie auld.

  3. Used the % in Lair idea tonight, taking some newbie players through a simple linear dungeon - they rolled a wandering encounter with Goblins - in lair, so I quickly used the goblin complex rules in AiF to generate a lair leading off for the dungeon. It's almost like How to Host a Dungeon.

  4. Very cool Sean. It's awsome to have inspired you to putt this to use so creatively. Tossing in the AiF goblin complex is a terrific idea. How did it go with your players?

  5. Positive reactions all round :)
    One of the guys who had played some 4e 'delves' remarked that it was cool how a chance encounter basically 'unlocked' another level of the dungeon, uncharted territory (for the DM as well), how they acted as a secret door to a hidden kingdom. Another said it felt more like a fairy tale, which given the heavy Poul Anderson influence on AiF, pleased me no end.

  6. Interesting. Just to be sure I understand the mechanic, this implies that most of the time you don't place the lairs beforehand, right? You have a some hexes mapped out in terms of terrain, and an encounter table. When the PCs enter a hex, you roll for an encounter. Say you get one. You the roll the % in lair stat to see if you have encountered a wandering band or stumbled onto the actual lair. If lair, you note on the map that a lair is located there. Correct?

    I find this very interesting, as it is sort of a late-binding method of determining hex contents. It's nice because it does not require as much prep. On the other hand, it also does not allow rumors to factor much into which direction the PCs choose to investigate (though presumably they could learn something about the makeup of the encounter table beforehand).

    1. Even better Brendan - the method is completely flexible. It can be used exactly as you describe - to place a lair wherever the PC's are. However, in the classic Hexcrawl, PC's are often not in a specific known location when they enter a hex (which are often measured in miles), so you can just as well have the lairs planned ahead of time and use the roll to place the PC's!

    2. That's a good point about using the encounter roll as a way to determine where the PCs are. Must consider further.