frankly I’d be down for making ninja looting dungeons harder as well, it’s equally ridiculous one pc can make hundreds of thousands of fang sneaking thru dungeons solo..
I feel this is a common misunderstanding of cause and effect. Technically the problem there isn't about the items, it's about how much gold has been pumped into the economy by the number of players (a.k.a. "inflation"). Items found in dungeons aren't inherently worth hundreds of thousands of fang, but PCs are willing to pay those prices because they have that much gold. So ironically, making ninja looting harder would drive prices up, not down.
Senna has taught you well! The greatest threat to Civilization is Inflation! Heed the tenets of Abadar!!!
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But on a serious note. There is a very real, very costly (to player count and engagement) method of inflation in games - and that is variable inflation of incentive, reward, and cost. Gaming terms for this are XP/Gold grind, power creep, and Old money vs New money.
In video games - particularly multiplayer MMOs to old school online RPGs like Ultima and Runescape, there was a notable problem in continuing to keep players engaged through growing end-game, or high-level content. The challenge to the developers was to continually create content that would keep players engaged and challenge their characters. This would result in increased level caps, new loot and gear to bolster a character, and new areas that required the absolute best, most optimal gear and strategy to overcome.
Developers are human beings, and along the way, they make mistakes - including the creation of loot that is far too unbalanced, the offering of too large an incentive for certain playstyles, and adjusting the rarity of certain necessary items to cause artificial inflation of price in markets/auctions. In initial creation, these acts cause a notable incentive, and player engagement - but often, they also begin to create an in-game wealth gap between a small percentage of players and the rest. How do we reverse this or at least curb it?
If in a small DnD game with players around my table, I award a magic item that is clearly far too powerful and has elevated one character above the others that it is impacting the game, I can talk with the players and most will agree to tone down that magic item to keep the game going. That personal connection does not exist as well in online RPG-style games. When in-game inflation of currency or items was fixed via the removal of coin or items, entire games have gone to the wayside in response. After all, there are no greater nerfs than that of removing or lessening in-game wealth. Players, regardless of their rationality, hate losing items and coin they rightfully earned - and that is fair!
All of that was a precept to what Porg is talking about. In-game currency has inflated, to a ridiculous amount, because over time, incentives have been found and capitalized upon in order to both secure large amounts of coin and secure dangerously obtained rare items. One only needs to attend an auction to see that the weights of supply and demand, and reasonability in price, are tossed out of the window. Coin has very little weight and value to it, for those who have managed to secure insane amounts of wealth - and they will appear each and every time to utilize that wealth that they have secured.
Progression and gaining incentives are something that cannot be removed without completely destroying the game. This balancing act is too difficult for anyone to truly solve without upsetting numbers of people. Not reacting to it has about as much harm as reacting to it.
This Geistonomics idea does create an incentive for larger parties, which are sometimes more difficult to coordinate. If the best, rarest items appear when only 20+ people are in the dungeon - then those items will become supremely inflated in value, purchased at insane prices by old money. I do like the idea of Geistonomics. I think there should be places in the server that come accompanied with incentives for involving more people - these incentives being unique experiences and rewards - but I believe there is something that can be coupled with it to help prevent it from becoming yet another source of rare, highly inflated items...
...and that is making the reward a quest item that can be gifted to someone present at its awarding, but that is all. Make a command for the character to be able to trash it - but these rewards cannot be traded, sold, etc. The item can only be secured through participation, and because of the large party structure, even the least combat effective persons can participate so long as the difficulty level is not insane.
Unique experiences, and unique rewards that only the participating players can achieve, will help avoid making this another problem of variable inflation imho, and also encourage everyone to go to these places to boot. If you create the Geistonomics situation and refrain from controlling the rewards, however, it will result in a lot of grief and inflation - because getting that item from the geistonomic dungeon to the hands of the wealthiest buyer becomes a rat race.