Huh. Fun name for it.

The past way mtg has done this kind of thing has been Lightning Elemental. But that doesn't let you direct the damage to a specific creature.

Your wording here feels natural, but I bet it'll give the comprules team a migraine. Normally I dvocate making cards shorter - but I think this one would benefit from being made longer:
Choose one -
* Deal 3 damage to target creature.
* Create a 3/1 red elemental token with haste. Sacrifice it at the end of the turn.

Okay that is a good idea. But I don't want the bolt to die to something with first strike before it can deal it's damage. Also I like the idea of being able to initiate an attack-like action outside of the combat phase. Which part makes the rule problems and how?

Proper rules will be needed for something like this. Without rules support, it doesn't seems to work, and is unclear how it is supposed to work, anyways.

If they can "block it as though it were an attack" a first striker would seem to work. If you need to kill the first striker, use the first mode?

As for needed changes - the rules currently assume that the only things that can be attacking are creatures. And they deal damage equal to their attack (which an instant doesn't have).

Certainly, this could be made to work - the natural meaning is obvious (treated as an attacking creature with power equal to the amount of damage it would deal). Though there's still nasty edge cases. What happens if they block this with an Ornithopter. The damage has been blocked - but the attacker isn't dead. So does this "damage" somehow sit on the battlefield? Is it enough of a creature to be affected by things like "All attacking creatures get +X/+X" - or trample? If so (and it feels like those should work) - could an opponent say "I block it with my only defender, that 0/1 that is absolutely vital to my plan. Now I cast Shock at it." Because it feels like that probably shouldn't work?
So some rules decisions would need making to support this. If a whole bunch of cards doing stuff like this were going to get made? Sure, make those rules calls.
For a one-off though? Do the 'nearly the same in terms of normal play, but much simpler' thing.

This is worded far more complicatedly than it needs to be.

"3 damage to any target. If this damage would be dealt to a player or planeswalker, that player or planeswalkers controller may have the damage dealt to a creature they control instead"

Not only do the rules currently assume that the only things that can be attacking are creatures (this is easier to fix perhaps, although this is not even a permanent, which complicates it a bit), but it needs a combat phase, too.

The "natural meaning" is not obvious to me. Maybe to you it is, but not to me.

I think you people are missing the part where it says "as if it were an attack". It's not an attack. It's not a creature. The only similarity this has with an attacking creature is the way it can be blocked. Letting the opponent redirect damage is nice but making them block it instead means they can only redirect it to viable blockers and they get blocking triggers. It can't be affected by any combat or creature related triggers. So obviously this spell resolves then the damage is dealt. You cast the spell targeting a player, they have no response and choose to block it with ornithopter, the spell resolves and then ornithopter takes all the damage and dies. Nice and simple.

Your opponents Blood Reckoning won't trigger but their Noble Stand will trigger. ­Predatory Rampage won't boost this spells damage but it will force your opponent to block this damage with any and all viable blockers.

That could be made more clear. Izaac's suggestion (comment 117370) makes it much more clear, and is supported by the rules. The existing text isn't clear or supported.

To make blocking triggers and other stuff like you mentioned to work, that requires rules support, to make it clear what it does; the existing text is not clear at all. (If making your owon set of custom cards, you can provide these rules with the set; but, that is not automatic.)

I think you're maybe thinking of "declare-blocker-it-takes-damage" as a much simpler step than it actually is. There isn't a magic object "an attack" to be as-if of. Creatures can be declared as attackers, and are then "attacking". The declare-blockers step then uses that to decide which "attacking creature" it is blocking. (And the comp-rules do explicitly call out creatures to block).

Then each creature deals damage equal to its power.

So; while this may seem nitpicky - all of that would need to be modified to support this new kind of card. And then robustly tested to make sure they didn't accidentally make any stupid loopholes or unintended consequences. If this was to be a major new theme, and there wasn't a way to easily reword the effect - then they'd do it. But for a single card, when there are multiple alternate ways to word it to get the result "Damage target creature, or let opponent choose face-or-creature" without needing such changes - I think they'd prefer the card change.

Which is a shame, since it does seem natural to me - "Something heading my way, I can have a creature block it, if I do, that creature takes the damage instead of me".

But.. as I said; it'll give the comprules team conniptions to make it work as-is.

Why do you want it to work that way? The wording I suggested functions exactly the same in every situation besides cards like Noble Stand. There's a decent design space for a burn spell that can be redirected to your creatures but why did you want it to combo with a handful of already unplayed cards?

Okay you're all totally ignoring me. It's not an attack. Stop talking about the rules of attacking because this isn't an attack! It's not that hard to wrap your head around when you remove it from [Mod Edit: Stop it. No need for that kind of language.]

None of you can actually give me an example of a problem so this will remain unchanged until somebody can.

You write "as if it were an attack" and then wonder why we point out that you need rules support for attacks to make that work?

I totally agree, in silver border land, the effect is mostly obvious and a couple of FAQ entries fixes it.

But to make it work for real - either the rules, or the card, needs to change. We have given several examples of missing elements. (There's no combat phase, so none of the attack/block rules apply. Assuming you make them apply, 'damage' isn't a thing you can block - so what does it mean when you do? While 'damage' is being blocked; what kind of an object is it?) These are all answerable, but the rules team (or, you know, you) would have decide on the answers.

Saying all that - it is a natural effect to want. It does feel obvious to me how it should work in the normal case. I just fear that were this to actually be templated, the card would get changes so that the outcome was the same, but the wording was different.

It’d be fine in silver border