Initially, I started this on Psarketos' Sway of the Stars thread, but it took on a life of its own pretty quickly. The discussion of Sway of the Stars as Shahrazad emulation got me thinking about something from many years ago, and I think there was at least one other Psarketos Magic theory thread in which I wanted to bring it up. So I'm doing it now. Starting a new thread because this is quite the tangent. Firstly, I want to note that while this story is hypothetical, meaning fiction, it's actually a kind of fusion of two different real-life incidents, but neither one individually works for my purposes when it comes to Magic theory, so I have to combine the two real events into one false one and exaggerate a bit. Not that it really matters, but there you have it. Also, both of my "based on a true story" events that I use as inspiration for this fantasy scenario on happened while mana burn was still part of the game. For our purposes, this will be a world without mana burn. I was actually opposed to the removal of mana burn from the game and argued against it here at the CPA, but I digress. Mana burn doesn't actually entirely invalidate the concept I have in mind, but it adds a layer of complexity to it and my scenario is a bit involved already. So to simplify the matter, let's just go with the official rules and have no mana burn... In this scenario, I'll be piloting a 60-card pile consisting entirely of cards from my favorite Magic set ever, Unlimited Edition. Here's my deck (which, alas, I do not own in real life, but perhaps some day)... 4 Black Lotus 4 Ancestral Recall 4 Time Walk 4 Fork 4 Timetwister 4 Wheel of Fortune 4 Demonic Tutor 4 Mox Pearl 4 Mox Sapphire 4 Mox Jet 4 Mox Ruby 4 Mox Emerald 4 Sol Ring 4 Dark Ritual 3 Regrowth 1 Fireball Now, some would call this deck unfair (among other things). In terms of Magic theory, we can pretty easily start to suspect that it is not the ideal first-turn kill deck for an environment with no restricted cards. But what if we want to build such a deck strictly out of cards from the greatest Magic set of all time (Unlimited Edition)? Still probably not ideal, but it looks like an excellent starting point. It's extremely fast, yet also one-dimensional, so opponents might be able to sabotage our attempts at winning. But my opponents, cads that they are, attempt to defeat me with decks consisting of cards from outside the glorious Unlimited Edition. How horrendous. At first, they are caught off-guard by the sheer speed and consistency of my deck. Oh, they try to race me with an early Entomb into Reanimate or to stop me with Force of Will, but their efforts fail. But they're starting to get wise to this. A well-timed Misdirection on my Fireball could be disastrous. It's just not fair: the new cards are so broken. I resolve to update my deck. Tomorrow, that is. Not just yet. And so I find myself sitting across from a new opponent. We'll call him, uh, Eddie Brock. Me: Mox Pearl, Mox Sapphire, Mox Ruby, tap the Pearl for Sol Ring, Time Walk, done. Next turn, I'll tap Sapphire and Ring for Timetwister, Mox Jet, Mox Ruby, tap Pearl for another Sol Ring, Black Lotus, and wow, I guess I fizzle. Pass the turn. Eddie: Island, Extract. Me: Fork the Extract. I search Eddie's library and find nothing of interest. I exile his Seventh Edition Vizzerdrix. Eddie searches my library and exiles my Fireball, of course. Confident that exiling my Fireball has utterly defeated me, Eddie Brock passes the turn. Eddie: You lose. Me: Do I? Black Lotus, Regrowth the Timetwister, cast Timetwister, Mox Jet, Dark Ritual, Dark Ritual, Demonic Tutor twice, Time Walk with Fork on my own Time Walk, done. Next turn, Ancestral Recall, Black Lotus, Mox Sapphire, Mox Emerald, Time Walk, Wheel of Fortune... Eddie: You can't win! I got rid of your kill card. You even wrote, "kill card" on that Fireball. You have no win condition. All you can do is take more turns. You have no way to kill me. But Eddie has it wrong... Here is where we enter the realm of Shahrazad Solitaire. I have lost my "kill card" for my deck. I cannot win through ordinary means. However, my deck has now "stabilized." It is easy for me to use a combination of Timetwister, Wheel of Fortune, and Regrowth to churn through my deck casting Time Walk and Fork (copying Time Walk) to generate multiple turns. I can power this engine with my Mox cards alone if necessary, but with the addition of Black Lotus, Demonic Tutor, and Dark Ritual, this is all even more explosive. It's also not strictly determinate. There is no guarantee that at a given point in the loop I will be able to continue generating extra turns. For example, I might cast Timetwister and draw into the following seven-card hand... Black Lotus Black Lotus Regrowth Dark Ritual Regrowth Black Lotus Dark Ritual But even though that will eventually happen, this deck is constructed such that the average turn can generate far, far more extra turns than would be necessary to make up for the turns in which no extra turns can be generated. Initially, when over half of my draws on average produce mana and do nothing else, it is possible that I get stuck, that I cannot find a way to cast Time Walk and must actually pass the turn to Eddie. But once we've passed a certain threshold, turns without a single Time Walk being cast become increasingly rare, and indeed turns with only one Time Walk become increasingly rare as well. Intuitively, once we know that once we've passed this threshold, we can continue taking extra turns indefinitely, never once allowing Eddie to take another turn. By Eddie's own admission (technically we didn't see his hand off the Forked Extract, so we don't know 100% of his deck but we're assuming it has no cards that can disrupt us on our own turn on the basis that he was up-front about this), he can do nothing to stop us and is effectively out of the game until the extra turns are depleted and he is allowed to untap. Infinite loops in Magic are powerful and can, in many environments, be practical enough to be competitive. But as far as theory goes, most infinite loops are straightforward because they are determinate. Fallen Angel eats Ornithopter and gets bigger, Enduring Renewal brings Ornithopter back, Fallen Angel eats Ornithopter and gets bigger, rinse, repeat. Once the loop is there, it's the same every time and every possible outcome is easy to account for. The loop in my deck, however, is indeterminate. I loop Timetwister, Regrowth, Time Walk, and Fork to generate extra turns, but the order in which those cards come up and in which other support for them in the deck arrives, well, that's random. And like I said, intuitively, we can see that once my deck gets going, it doesn't ever have to stop. That might not be the case for every indeterminate loop! I don't know if Magic has any such case. I do not remember ever having seen one, but it seems logical that such a deck could be constructed. What I mean by this is that we might have a deck of such a composition that it could generate a loop that would, eventually, fail.