Programming question

Hi people.
First, thank yo so much for the availability and the quality of your programming work, I really enjoy playing dotp modding decks for a couple of months
, and especially making my decks and cards.
Looking at your code, I've learned how to write some simple cards (I hope to share them someday) like the funny Ovinomancer, Thawing Glaciers or Soratami Rainshaper, but I'm completely stuck with the Offering feature of the Patron of the Moon card as I can't find such a feature implying tests and maths in previously released cards, and as I'm really far from being a real programmer...
How would you code that ?
Thank you very much in advance,
Gopher.
First, thank yo so much for the availability and the quality of your programming work, I really enjoy playing dotp modding decks for a couple of months

Looking at your code, I've learned how to write some simple cards (I hope to share them someday) like the funny Ovinomancer, Thawing Glaciers or Soratami Rainshaper, but I'm completely stuck with the Offering feature of the Patron of the Moon card as I can't find such a feature implying tests and maths in previously released cards, and as I'm really far from being a real programmer...
How would you code that ?
Thank you very much in advance,
Gopher.