fascinating. i get how it works, but wonder if it can't be worded more clearly

It should be "a random number of targets chosen at random." Unfortunately, a random number is always equal to infinity. Maybe "a random subset of targets"?

Edit: I just realized this isn't a joke set (I looked at the card and assumed it was). I don't think this can actually be made without a fixed number of targets. The targets can be random, just not how many.

"Roll a die, that number of random targets..."? (Ignoring the whole "This is un! Un Un Un!" thing)

I have a D100; can I roll that? What if I roll the planar die? :)

New wording any better?

Mm, yes, I think this works. (Could be templated slightly differently, but I think the mechanic is fine rules-wise.)

Really, if Pyroclasm is fairly costed, I don't see why this can't cost . Other than that, I rather like the card.

I... guess you can use certain unny cards to try and make thus one sided. This would be SO fiddly to play against a token deck, but very funny.

It's an instant so I think the 2R is fair. How would you template it better?

"For each creature, flip a coin. If you win, ~ deals 2 damage to that creature." maybe? Your wording seems working to me though, and only 2 words longer.

Yep, pretty much how Vitenka put it. Similar to Fighting Chance.

Is this something that should really use win/lose terminology instead of heads/tails? "Yay, I won the flip! That means...I get to deal 2 damage to my Mons's Goblin Raiders. Oh damn."