If your game contains lots of levers that reliably dispense tradable reward pellets, then it's safe to expect that your game will attract minmaxing Achievers. And once they're your predominant player base, your game economy will inflate or deflate according to their whims. Assuming you don't want Achievers to be too discouraged from playing your game, that means changing how collectibles are generated.
I would suggest that the most important tradable collectibles commonly implemented are:
- combat gear (weapons & armor)
If these two really are the the core collectibles, then I'd like to see a two-pronged approach to reducing their "system reward" aspect (and thus their economic impact as Achievers try to generate them):
1. Combat gear can't be purchased or traded -- you can only get it if it's assigned to you.
To merit combat gear, you're assumed to be a member of some in-game profession that's authorized to carry arms, such as a police force or a military organization. Rather than buying gear or taking it from the nearest corpse, you get it by requisitioning it from the organization.
Whether you actually get some bit of gear you've requested could be based on factors such as:
- your rank (based on your contribution to winning difficult battles)
- your need (as perceived by higher-ups and/or Supply bureaucracy)
- your visibility (earned any medals or unit citations lately?)
- availability of government funds authorized for the police/military
- requested gear has been created by crafters or NPCs
- having a logistics expert (i.e., scrounger) in your squad/unit
- random factor (war is hell)
(Note: If you do go this route, it would probably be a good idea to have lots of exciting combat content.)
2. Money can't be looted through combat operations -- you're paid a salary. (Again, if money was something you needed, it would have been assigned to you.)
Making money ought to be the province of the business-oriented character (who IMO should not also be a combat-oriented character). Of course, if you allow players to collect money, then you're back to needing some game rules that discourage the minmaxers from mindless lever-mashing. (I like the idea of business gameplay being balanced by government regulations and media exposure, with players themselves exercising both functions and with other players acting as checks on those two roles in turn. No doubt there are other ways.)
Meanwhile, characters who prefer shooting mobs and blowing things up should join the military... but they shouldn't expect to get rich that way because they're already being rewarded with the excitement of being shot at. ("You're in the Army now...", etc.)
By removing most of the lever-pushing sources of the two major collectibles from the game economy, I think you'd wind up with a more stable game economy. Limiting the collectability of the two most volatile components of most MMOG economies -- combat gear and money -- should reduce the economic impact of minmaxing behavior.
1. Have too many players been conditioned to believe that "no lewt" == "no fun"?
2. Has something like this already been tried? By what game? What happened?