I’m going to be running a game tonight where certain resources are finite and have to be conserved for the right moment.
I was thinking of a supply mechanic that would fit in with the core mechanics of the game and I thought why not use Hearts for the amount of supply a device has to start with (it’s power reserve). When the player uses the device you roll Effort and subtract that from it’s Heart.
The beauty of this system is you can alter the amount of effort used depending on how hungry the device is on the battery or the environmental conditions. For example it would normally it would be Weapon Effort, but what if you were using it for prolonged used, roll Magic or Ultimate Effort.
In this way it is another choice for the players, do they use the device in question now, risk burning it’s uses up or save it for later when needed.
So you can vary the Hearts on how much supply it starts with and alter the effort depending on the mood of the situation or your game. I would not want to use it for supply for everything as it would get tedious tracking several different items, but important equipment that adds tension to the game.