I''m currently putting together my design document for a game similar to the old multiplayer game M.U.L.E. You old-time gamers know what I''m talking about, right? In any case, the only algorithmic stumbling block I''m coming across is a convincing supply/demand algorithm. For those of you who aren''t familiar with the game: There are three different resources. (Well, four, but the fourth has a different, easier system.) The four players each have however much they''ve produced, and there''s a store that has its own supply of the resources. There''s an auction phase, during this phase the store has a set price at which it will buy the resource in question, and a set price at which it will sell the resource. The difference between the buy price and sell price is a constant for each resource, so all that matters is how much the store will pay to buy the resource. This number depends on how of the resource the store has, and possibly on how much the players have, and how much they''ve been paying each other for it. The prices range from 10 to 265, but that''s not vital. So, any suggestions on a good algorithm I could use? The one the original game used would be nice, but isn''t necessary, since I''m not quite making the exact same game.