Using these custom frost dice in Cthulhu Death May Die is straightforward. Just roll them as required during the game to determine various actions and outcomes. Remember, the dice are a Kickstarter exclusive, so they're unique to this special version of the game. Regarding the paid add - ons from the Kickstarter Campaign, they're not included unless it's specifically mentioned. As for maintenance, keep the dice in a dry and clean place to prevent any damage or discoloration. When you're done with the game, simply store them safely. And if you're unsure about how to use the dice in a particular situation during the game, refer to the game's rulebook. If you still have questions, don't hesitate to contact The Game Steward for help.