Burn damage doesn't do much for creature damage sources. The progression of damage is still linear. All it would do is delay some of the damage at the beginning until after the creature dies:
Turn | Damage |
1 | 4 |
2 | 4 + 3 |
3 | 4 + 3 + 2 |
4 | 4 + 3 + 2 + 1 |
... | ... |
Death - 1 | 4 + 3 + 2 + 1 |
Death | 3 + 2 + 1 |
Death + 1 | 2 + 1 |
Death + 2 | 1 |
Spoiler for snip:
As you can see, this is little different from a 10-attack creature (very similar to graboid actually). It doesn't matter what the burn curve is, it is still going to be linear damage, just like any non-growth non-poison creature.
A single dose of burn damage is more interesting. Assume that the average game lasts 8 turns. Then a 6-damage burn does 21 damage if played on turn 1-3, but 11 damage if played on turn 7. So it is like a 2.625-attack creature when played on the first turn, but like a 5.5 attack creature if played on the 7th turn.
A more general mechanic is "Do X damage in Y turns." Burn 5 is "Do 5 damage in 0 turns + 4 damage in 1 turn + 3 damage in 2 turns, etc." Perhaps the Do X damage in Y turns is more interesting when applied just once. Consider
Stones of Prophecy 2
(Perm) -- Doom: Do 50 damage after 10 turns. Immaterial.
This is a bet that you can make the game last at least 10 turns from when you cast the spell, giving your opponent a 1-card advantage. That's an interesting wager that doesn't exist in the game now.
A single dose of burn damage is also an interesting effect - akin to a creature with attack equal to the turn count when it was played.
Actually, I think the situation for a creature burn source is different.
Consider:
-Creature damage contributes A*p burn counters (where p is the percentage of damage converted to burn)
-Burn counters are consumed at a rate of B*r (where r is the percentage rate of burn release)
-This means that burn counters at turn i, B[ i ], can be expressed as:
B[ i ] = Floor(B[i-1]*(1-r)) + Ceiling(A*p)
...Floor means round down, Ceiling means round up to nearest integer...
-This will eventually lead to a fixed point of approximately A*p / r
-This gives a cap damage per turn of: A+ A*p/r * r -> A*(1+p)
There is an interesting twist here, the cap is purely related to p but the rate at which the cap is approached is controled by r
So in short, we can control the max boost to dpt using p and we can control the rate at which this is approached using r.
This works well for one of my card ideas:
Card Name: Ferrocity
Element: Life
Cost: 6
Text: "
Bleeding Wounds: Your creatures' attacks will inflict an additional 50% damage over several turns"
So with 2 of those in play it would allow the total creature damage per turn to cap out at 2 fold (like having a permanent sky blitz)
Of course, depending on the rate of release chosen, the time it would take to reach the cap could be controled.
I'm still working on the math for number of turns to cap out versus the value bleed rate.
This could easily be adapted to a fire card instead.