undecim wrote: mike-l wrote:
In order that it can't simply be brute forced, you're going to need play to go on indefinitely, so both players are going to need multiple copies of something like http://magiccards.info/query?q=!Quest+f ... nt+Secrets
. You're also going to need a resource that can be accumulated indefinitely, eg counters.
So, something like, each player has a library consisting of one timetwister
. They each have a 0/1 monster with N +1/+1 counters, both have a dismember
, and then a third 'Collatz' card which does the collatz process on all counters on the board. Then it's a tie for all N except for those which the Collatz fails. They each have enough mana, and the counters got there in the first place via other cards that are now exiled with no return condition.
Not necessarily. There are plenty of permanents with optional actions (i.e., when X you may Y). There are several combinations that result in infinite loops if both players continue this infinitely. This can mean that not only a single turn, but a single stack can continue indefinitely.
Also, for those that don't know about it: http://gatherer.wizards.com/
You cannot have an infinite loop caused by choosing to use "may" actions indefinitely. If an optional action is involved, you must show your opponent the loop and then declare how many times you are going to do it, and they have the chance to interrupt it. So an optional combo can not continue indefinitely, since you must define it.
For example: Say you control a Fiend Hunter
, which has exiled another Fiend Hunter you control. If you play another Fiend Hunter, targeting the one on the battlefield, you can create a loop of Fiend Hunters exiling each other. However, since it is a "may" action, the infinity rule requires that you say how many times you are going to do it (say you have a Soul's Attendant
on the battlefield, you say "I do this 1,000,000 times and gain 1,000,000 life.")
Even on a must, if you choose a target (such as Oblivion Ring
) if there is another valid target that would halt the loop, you are required to break the loop. So if you wanted to do the same thing with Oblivion Ring as you did with Fiend Hunter, you may only loop the exiles a definite number of times before declaring another target, UNLESS there is no other valid non-land permanent to target, in which case the game ends in a draw.
So I don't think any kind of looped combo would work for this, unless you say "I repeat this loop until I reach an integer that violates the Collatz Conjecture," but I don't think that qualifies as declaring a number, nor does it really fit the spirit of the problem.