SM is not your standard card game since you are setting up you team and then they auto battle. It’s more about making the best team with what you have for how much mana that fight is. Along with taking advantage to what the ruleset was for that match.

Holybread a browser RPG which is coming out some time this month on Steem is a great example of only taking fees if the item sells.

It would be nice to see more games have internal markets to avoid any transactions until an item has sold when it then needed to be written on a blockchain. While still giving people the choice to shop around and pay other costs if they want to sell in other market places with smart contracts.