Okay people, Reed has not been here for a while. So if you want to improve upon this, just start throwing out comments and ideas.
These cards always struck me as vaguely Amberititic, with a Shadow of a Noble being the card's creator. (Could be of the blood, who knows). They seem to embody cosmic forces, yet at the same time, be a shadow of the trumps.
The story about the witch and the curse and the selling of the card is just odd. So I ignore it.
So there are 11 cards left floating around, each with celestrial script.. balancing the good and the evil to allow for access to the unliving.
The chants? where are those. I would assume they are on the cards.
Now this "cost" works pretty well for manna use/ power points systems. Over expenditure can be lethal. So in a Basic Roleplaying, you would lose one pow point per 3 minutes, thus dying when you reach sufficiently low. Manna would make it easier for a mage to use this, but a fighter with a low manna, would not last as long. In more simplistic systems, harder to resolve... perhaps using long term fatigue or hits lost.
This is a high cost for speaking with the dead, a dark curse as well, I feel this could also be played by aging the summoner, taking a year of life for every minute, but that is harsh as well. Why not just use a cheaper, less deadly way to call the dead. Now, if you could substitute the target of the curse with another in your place, you could sacrifice children in your pursuit of knowledge leaving them old men or tapped. Oh man, this is harsh if used right. Go to Comment