Never played the card game, and didnt know anyone who did
In the video game its measured as Rads, and if you accumulate too many Rads, your stats begin to drop and eventually your character dies
Now if you want to avoid pushing a rights-holder towards actions, it might be best to follow some of the unwritten rules of fan-art, namely: it doesnt claim to be, or at least cant be reasonably mistaken for, official authentic merchandise it doesnt use any existing art assets from official merchandise and therefore is 100% fan produced it doesnt interfere with the rights-holders from being able to sell their own products it isnt something that the rights-holders believes will dilute the perceived public value of their property Long time PA
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For example, if a spell has the text "Destroy target creature," but there are no creatures on the battlefield, you cant cast that spell because it has no valid targets