So a question keeps cropping up at our weekly game night: one of our players keeps insisting that if a card costs 0 resources to play, then it is perfectly acceptable to play such a card in any deck, regardless of sphere matching. For example, he might play a Lore/Tactics deck and then splash in 3 copies of Daeron's Runes (a Lore sphere card that costs 0 to play) and argue that he can play it because it has a cost of 0. I have always been under the impression that regardless of the cost of a card, you had to be able to "sphere match" the card's symbol to one of your heroes in order to put that card into play. Am I right in my interpretation, or is he right? I think I know the answer already, but thank you all for your help, of course, I may be wrong afterall.