During the step where you can use activated abilities with the Reaction tag to Add resources to pay a spell's costs, can you exhaust a rune to produce 1 energy? Is 'Add' different from 'produce'?

Ruling: Yes, you can exhaust a rune to produce 1 energy during this step. In this context, 'Add' and 'produce' are the same.

Nuances:

• The rule specifically allows activated abilities with the Reaction tag that Add resources to be used during this step
• 'Add' and 'produce' function equivalently in this context