Cash and Stocks

I have no complete answer for the issues I raised in the post about merchants and how their cash reserves and goods stocked would change from visit to visit. In the past, I skipped updating a merchant's cash after PCs made their purchases. It never actually came up later, but I think I would only treat money received from PCs as cash on hand for that one session; by the next session, presumably a few days have gone by, and the merchant has spent the excess. I also rolled for number of torches, ropes, spikes, etc. in stock if the players tried to buy a large number of these. And I might be prone to make a 5+ on 1d6 roll for rarer items, to see if they're in stock at all. That's almost like the technique FrDave mentioned, and it approaches the way I probably would formally handle it.

What I'm thinking is that it would probably be best to rate merchants as 10 gp, 100, gp, 1000 gp, or some other power of ten; that rating covers both the typical value of any item they stock and a general figure for cash on hand. For any common item a player requests, if the value is less than the rating, the merchant has 2d6 units of that (one unit depends on how much of a given item someone would normally keep on hand; daggers would be sold individually, torches in bundles of five or ten, arrows in bundles of 20.)  if the item's value is higher, roll 3d6-10, so that half the time the number on hand is 0 (out of stock.) If the value of the item is ten or more times the merchant's rating, drop one die (2d6-10.)  For 100 x merchant rating or for atypical items in general, there will be one item in stock on a 5+ (1d6.) Cash on hand can be based on a 2d6 roll as well; the lowest die, minus 1, is multiplied by the rating, then the total of the two dice is added.

Rules summary:

• Merchant Rating: 1, 10, 100, 1000, etc.
• Common Items in Stock:
  • Value < Merch Rating: 2d6 units
  • Value < 10 x Merch Rating: 3d6 - 10 items
  • Value => 10 x Merch Rating: 2d6 - 10 items
• Uncommon Items, or value => 100 x Merch Rating: one in stock on 5+ (1d6)
• Cash on Hand: sum of 2d6, plus (lowest die result -1) x Merch Rating

Reroll every session, or every week. Actually, most of the time, these rolls won't even come up; Cash on Hand only needs to be rolled when the PCs are selling to or robbing from the merchant, and even the merchant's most common wares only need a roll when the players buy more than two of any item.