These are so amazing. I just want to thank you for this.
This is a Usage Die chain, for tracking supplies. It's a pretty common mechanic for things like torches, rations, etc. When you deem appropriate, usually after use, or every few rooms, etc. Roll the current die. On a 1 or 2, it is reduced. When the d4 is rolled, and on 1 or 2, you are out of that supply