Resource Management is a much maligned term these days.
Back in the early days of D&D, resource management was critical to a successful dungeon delve or wilderness adventure, and important even during urban interludes. There are probably very good reasons why resource management has been all but abandoned in the recent iterations of D&D. I'm guessing it takes time away from the "fun" parts of D&D, and is seen as just another way for the DM to "screw" the players, by designing an encounter where a particular ignored skill or piece of equipment turns out to be critical to success.
I'm probably somewhat unique in this regard, but I always enjoyed the resource management side of the game, and figured that the DM wanted us back next session, so would "play fair."
My renewed interest in old school D&D got me thinking again about resource management.
The character record sheet is where most of this resource management occurs: as characters obtain and consume resources, they add to, or subtract from, their character record sheet. This is wholly appropriate, but the textual record of ones abilities and possessions is not very interesting (visually) and recording changes in resources can sometimes be forgotten (both to the benefit and detriment of players).
In addition, I had recently been bitten by the brevity bug: I have been forcing players to use a 4"x6" file card to keep track of their characters and belongings. Some players would need a magnifying glass to decipher the information on their file card!
As they say, when you have a hammer, everything looks like a nail. Similarly, since I have the game Magic Realm, everything can be solved using one of its game elements. In this case, Magic Realm employs small, 1"x1.25" treasure cards, along with various equipment chits, which a player keeps in front of them to evidence ownership of a particular item. When they exhaust or lose that item, they forfeit and return the treasure card or equipment chit back to the gameboard.
My desire to simplify resource management a la Magic Realm was the impetus behind my search for a suitable set of treasure and equipment cards.