Economy in Roguelikes - Part I: Thoughts

In games that even roughly follow the RPG template, as the game progresses the player or party increases in power on two axes (axis plural apparently, I love English). One axis is character strength or experience, the other being character equipment and items. As someone who's creating a game, specifically a roguelike, making these areas of the game interesting is critical to my success. I'm going to cover some of my recent thoughts on the second area, equipment and items, in a short series of articles.

Anyone who's played a recent RPGish game has seen the drill. You start off equipped no better that a set of dirty rags and a dull knife and end the game in shiny enchanted plate armor and a +5 sword of awesomeness. This provides both a "carrot" to the player (look at how awesome your equipment is), and a "stick" (get behind on the equipment curve and suffer). In almost every game, the way one goes about this is pretty standard.

• Enemies drop trash items and/or cash that one collects
• Enemies (sometimes bosses) randomly drop items worth keeping
• Unused items can be sold to shops for cash.
  
• Cash can be used to either buy new equipment, gamble for new equipment, or improve existing equipment

There are some consequence to this system, one major one that has come to my attention is what I've seen called the "vacuum cleaner" behavior: Since in roguelike you have one life, people play optimally. Since every item dropped can be converted to cash, which can be converted into power, one should collect every item and return it to town to sell. This is generally boring, so games have come up with "band-aids" to patch over the issue.

• "Town Portal" scrolls, to make return to the market less painful.
• Pack mules or Bag of Holding - Increase amount one can carry, making return trips to sell items less frequent.
• The items enemies drop are low weight and stackable (Final Fantasy XII), also reducing frequency of return trips.
  
• Pets who can return to town and sell items (Seen in Torchlight)
• Transmute spells, which will convert items to cash.
  
• Shops and merchants who are co-located near/in the dungeon at hand.
• Have a time system, either food or a deadline, which punishes players for returning to town more than the item is worth.
  
• Remove the selling system in its entirety (Crawl)

The other half of the issue is returning home to buy better equipment. This almost always follows the Sorting Algorithm of Weapon Effectiveness (read this link). The ways I've seen new equipment introduced into game include:

• As you travel farther from the starting area, or visit new towns, better equipment appears for purchase. 
• As you progress in the plot, items shops everywhere restock with better items
• Many items exist for purchase from the start of the game, but you can't use the good ones due to lack of skill, strength, or level
• Many items exist for purchase from the start of the game, but are priced out of range of all but the most dedicated grinding players

Analysis of these thoughts and my plans for Magecrawl's economy will have to wait for another post. Let me know if I missed something, or your thoughts in the comments.