Howdy! Really impressed with what you've done here. I really like how everything interlocks so that coin value, usage dice, DL, and everything all scales in unison. I did a little solo adventure and was super pleased with the balance you've struck here.
Thought on "forgotten" slots. I considered upping the cost to 15 coin (or even 20) because 10 is the average cost of a 2UD item. This way a player is rewarded for choosing items in advance rather just having a bunch of forgotten slots. Then again, I hate shopping so... I dunno.
Second, I did a little math to try and calculate probabilities and it seems that the DLs of 15, 20, and 25 seem like they might be a little extreme. If you have 11, an average stat, then your chance of success on a 25 is 9% (which actually feels pretty good, 1 in 10) while the chance of failure on a 15 is like 1% (which feels crazy easy.) Have you considered interim DL? A spread of 15, 17, 20, 23, 25 would mean you had some middle ground. If you had an 11 a DL of 17 would mean a 10% chance of failure and a DL of 23 would have a 26% chance of success.
Third, I thought about creating some supplementary material or fan content. What are your thoughts about releasing this as Creative Commons so others can build on the foundation? If I wanted to build my own magic supplement or such, would it be acceptable to do so? What if I wanted to sell such a supplement?
