Inventory management is a part of most ongoing D&D games. In some games, it is a background element. The Dungeon Master lets the characters take anything. Adventurers are the ultimate packrats. They love stuff, particularly shiny stuff. And when the time comes to sell off goods, characters can dump their packs’ voluminous contents on the countertop of the nearest shop to receive a proportional amount of gold.
In other games, inventory management is its own mini-game. Players might have to track weight, space, and expendable resources, such as food, water, and ammunition. Neither system is inherently wrong; the usefulness of inventory managements depends on the tone of your game and the degree to which the players are willing to buy into it.
In my recent Dark Sun game, I decided to implement rigorous inventory management standards. In my previous two 4E games, I let players ignore ammunition, weight limits, and resources, and I let them conduct business at shops during off-game time. Managing resources was not integral to the setting or the tone of those two games.
Dark Sun is different, because characters live and die by the resources they carry on their sweaty backs. Characters have to make tough choices about what they carry with them and what they leave behind. In any D&D game, Dark Sun or otherwise, inventory management comes down to two things:
The survival factor of inventory management comes into play only in settings where the natural resources are limited. Gamma World and Dark Sun are examples, although with Gamma World, the tone of the game makes the need for such a system questionable. An average D&D game, in which sojourns into the wilderness are scarcely more than a few days, makes survival-based resource management unimportant. Characters have frequent access to taverns, farmsteads, and bountiful forests filled with delicious woodland creatures. However, if you want to experiment with forcing players to manage their resources in a traditional D&D game, the Underdark is a great place to do so.
In my opinion, money is too abundant in most D&D games. When adventurers are carrying around thousands of gold pieces by level 3, money loses its meaning. In my recent Dark Sun game, I divided all monetary rewards by 10 while leaving costs the same. In other words, when the characters would normally receive 10 gold pieces in treasure, they instead receive one gold piece. As a result, I’ve seen players begin to hoard money and save up to spend it on mundane resources. When gold and silver are limited, the choice between buying an extra survival day and buying a second weapon in case you break your first ones becomes an interesting choice (rather than an obvious one—the obvious choice being to buy both, since you can afford both).
To promote money as a resource that must be managed, I’ve gone back to old school shopping. To buy or sell equipment, particularly when the characters are not in a major city, I require the characters to go find a shop and see what that shop has available. To that effect, I’ve created a Equipment Tables in Microsoft Excel that determines what resources a shop has, and whether the price is inflated or deflated based on supply. I realize that doesn’t sound like the most exciting experience, but it actually gives me some solid hooks for roleplaying and provides a degree of verisimilitude. For example, when the characters come across an elven trader on the road, I can drum up some supplies from my list, and those supplies tell a story about what that elven trader has been doing (crafting weapons, stealing from nearby caravans, buying and selling from Balican mercenaries, etc). Having an inventory list for a shop tells me what a shopkeeper will or will not pay for. If a shopkeeper already has four flails, it’s unlikely he’ll want another one, or at least that he’ll pay well for it.
Having players manage their resources promotes verisimilitude in your game, but it should be used with caution. Inventory management is a mini-game that not every player likes, and it requires fastidious note-taking and players willing to play by the rules. As always, talk to your players about your intentions, and find out whether it’s something that is rewarding for them, or whether they feel like it distracts from what’s important in the game. Manage player expectations. In my game, I asked the players how they felt about it, and they agreed that it made Dark Sun feel more gritty and post-apocalyptic. In another setting, they might feel completely different.