Handling asymetrical loops

Asked by BlueScope 9 years ago

The question is specifically about Viridian Joiner and Umbral Mantle.

As far as I'm aware (though I couldn't locate it in the rules), you can repeat an infinite loop a specified amount of times, as long as you can name a set of rules by which the loop will be executed. For example, a Splinter Twin on a Pestermite can be tapped and untapped 1000 times to create 1000 copies - pretty straightforward.

I'm not sure that's the case with the aforementioned cards, as the first time you activate Joiner's ability, you'll add to your mana pool. Paying 3 and untapping it will give it +2/+2, and now if you tap it, you'll get . Doing the same again will give you , and so on. However, every time you activate it, you have to pay to untap it.
If I'm not mistaken, the formula to calculate how much mana you generate from this for a set amount of activations would be A×2+P-(A×3)-2 green mana, where A is the amount of times Joiner has been tapped before (and if you assume that only green mana will be spent to activate Umbral Mantle's ability), P is the Joiner's base Power (normally 1) and 2 accomodates for the mana you have to sink into the Joiner before he goes infinite.

Now, my question is whether that's a reasonable sequence to make, or whether that's going too far. It would also be awesome if someone knew where exactly that rule is located in the rule documents, as I'm at a loss on that one...

Epochalyptik says... Accepted answer #1

You can shortcut this because it is a predictable sequence. You know that Viridian Joiner's P/T will increase by 2 each time and that you will get a corresponding increase in mana for each iteration of the loop. As long as you are able to accurately calculate the total P/T of Viridian Joiner and the total added to your mana pool after the loop is complete, you may propose a shortcut.

716.2a At any point in the game, the player with priority may suggest a shortcut by describing a sequence of game choices, for all players, that may be legally taken based on the current game state and the predictable results of the sequence of choices. This sequence may be a non-repetitive series of choices, a loop that repeats a specified number of times, multiple loops, or nested loops, and may even cross multiple turns. It cant include conditional actions, where the outcome of a game event determines the next action a player takes. The ending point of this sequence must be a place where a player has priority, though it need not be the player proposing the shortcut.

October 11, 2015 9:55 a.m.