Oh, that's interesting. It's usually just "5 dmg to target creature", but sometimes it will matter that you can shrink their creature on their turn and have it still be small on your turn, or vice versa.

I think it should probably cost 2R at least, as it's usually at least as good as "5 dmg to target creature". And note, I think -0/-X is usually black, although I think it could be red.

Red would really like to be allowed to phrase this "Target creature takes 5 damage until the end of next turn"

No wait, that's not red, that's just me.

As written, yeah, this is a black card. But give it the text

> Staying Power - ~ deals 5 damage to target creature. Damage isn't removed from that creature at the end of this turn.

and it's suddenly a red card. (Kind of like Puncture Bolt.)

Yeah, that would work. Or I guess, you could do "~ deals 5 damage to target creature and another 5 damage to it at the beginning of the next upkeep" if you wanted to avoid the funky templating (although I too think the "not wear off" version is interesting).

At seemingly everyone's advice I've changed the -0/-5 to "This damage doesn't wear off until the end of the next turn."

And to save the rules gurus some time, check out the reminder text for Time Stop. "Wears off" is the official wording for what happens to damage during the end step. Any other advice on how I might need to reword this card or is everything good?

I just liked the wrongeness of "takes damage until" It does still seem pretty damn powerful. Incinerate is dealing 3 with an upside; although that's not so maybe 5 with an upside is ok.

I've looked at the cost of cards that deal similar damage and I see stuff like Fiery Conclusion Shrapnel Blast Artillerize Goblin Grenade Lightning Axe and Magma Rift with costs all over the place from to all with additional costs and varying between instants and sorceries...

Maybe this card is a bit under cost... The design skeleton on my computer really just needed a common red damage spell for dealing with creatures. Power level can be adjusted later.

For now, how does the rules text look?

The duration-modification isn't reminder text, so it shouldn't have parentheses. Apart from that it looks fine. I'm not sure you can always argue templating from reminder text (I remember Obsidian Fireheart), but I don't see any reason why this shouldn't work.

I agree the power level is a bit too high (every other 2-mana burn-for-5 has had a card-disadvantage additional cost, not a benefit), but as you say, you can tweak that later.

BTW, suppose a 10/10 is hit with this and a Lightning Bolt. Are you imagining that next turn it will still have all 8 damage, or still have the 5 damage from this but not the 3 from Bolt?

Rules look fine. I agree, I do like "takes damage until" because it's a lovely way of phrasing it, but I don't think it would ever actually be printed.

For now, I'd probably spell out "until the end of the next turn" on staying power cards, but it may be possible to make that an inherent part of staying power -- I wouldn't worry about it, I'd wait and see which cards you design and then you can change the wording later if necessary.

I agree that 5 dmg is too much for RR; even if it didn't have staying power, you rarely get 5 damage for less than 4, and almost never without another drawback as well. Conversely, with a small upside of staying power, this would be a good opportunity to make a combination of costs which is usually unnatractive (such as 1R for 3 dmg) but would be playable, without it being strictly worse than an existing card.

@Alex Only the damage from Deep Wound would remain on the creature. So the Lightning Bolt would wear off normally, but the Deep Wound damage would remain.

It's one of the reasons I think the reminder text needs to be templated this way to explicitly explain what it's doing mechanically. As nice as "takes damage until the end of the next turn" may sound, damage is not treated in the rules as "until end of turn" or "this turn" so it can't be handled exactly the same as those kinds of effects.

In some ways I'm trying to treat Staying Power as a kind of "Rebound" that simply lasts two turns instead of getting a free copy of a spell during your next upkeep (see Emerge Unscathed).

The way you have written Staying Power here means it's an Ability Word and not a keyword. That means that it has no actual rules meaning, and that the reminder text shouldn't be reminder text.
That aside, I like the concept of this card a lot.

One of the things that makes reminder text reminder text is that the card would function exactly the same if it weren't there. It's just spelling out what the non-italic rules text implies. So if you want to modify what the non-italic rules text would do, you need to make that rules text, not reminder text. E.g. Incinerate's "can't be regenerated" clause isn't reminder text, because it's modifying the damage.

I love the idea of applying staying power to damage.

I like this keyword.