I have a gameplay idea where players need batteries to open doors and power things. Batteries are scarce, but there are lots of places they can be used. So, when a player gets a battery, the counter goes up by one. When they use a battery, the counter goes down by one (so long as they have any).
I've read about the 'game_counter' but what I’ve read is it only works for exact matches (=) and can only count up. Conventional "key"s arn’t suitable here as batteries are not tied to specific doors, and their quantity across the map is arbitrary.
I thought about having two game_counters, one for "found" and one for "used", but I don't know of a way to check the state of
found > used
.