Created for Challenge # 013.

Completely changed from my first idea ("Whenever ~ attacks choose a creature defending player controls at random. You control how that creature blocks this turn.")

I was going to make it more complicated and have the damage be greater or lesser, but decided to start with the simple version. I'm not sure what proportions give a fun, not too complicated, and not too painful feel; I'd rather both players occasionally felt lucky rather than always feeling like they needed to take bad risks.

There's a one in eight chance that this will turn into a Lightning Bolt (or better). That sounds rather exciting. I don't think it needs to get more complicated than that.

I didn't intend for it to be cumulative. I assumed "additional" meant "one more instead", but I'm not sure what the correct templating would be (Pyromancer's Swath suggests it should be "deals that much damage plus 1 instead").

OTOH, there probably should be a cumulative version, perhaps just a shock variant. I'm not sure if it should just be coin-controlled, or if it should be based on the top card of your deck, or something ("~ deals 1 damage to target creature. Clash with an opponent. If you win, repeat the process, and you may choose new targets for the spell."?).

You want this to say "If a source would deal", not "Whenever a source deals". That's the sane way to do it anyway, and it also gives you the can't-apply-twice-to-the-same-event rule for free.