All permanents are creatures

There's a quite famous combination of two cards in Magic the Gathering which, if they are on the battlefield at the same time, make all permanents artifact creatures: Mycosynth Lattice and March of the Machines.

(As you may know, or if you have read my previous blog posts, an effect making something an artifact creature has an implicit "in addition to its other types" without the effect having to specifically state it. This means that all permanents retain their other types in addition to being artifact creatures.)

This combination not only causes all kinds of shenanigans, the least of which is most certainly not the fact that all lands die because of being creatures with 0/0 power/toughness (unless there's something else increasing their toughness), but it also allows many interesting interactions with non-creature permanents that are not normally possible (because most of the "interesting" interactions usually target creatures and nothing else.)

Just to mention one of the numerous possibilities, take for example the situation where Clone enters the battlefield as a copy of Garruk Relentless.

Under the current rules (as of writing this blog post) both of them would simply die as a state-based action due to the planeswalker uniqueness rule, so nothing special happens. However, with the soon upcoming Magic 2014 rules change the Clone can remain on the battlefield as a copy of Garruk. (If Clone was cast by an opponent, it just stays. If it was cast by Garruk's controller, he or she can choose which one stays and which one goes to the graveyard.)

(Note that as Clone enters the battlefield as a copy of Garruk, it will have 3 loyalty counters, because that's a property of the Garruk card.)

It was possible to have Clone remain on the battlefield even under the old rules, but it required a much more contrived set of circumstances. The new rules make it much simpler.

So Clone is now a copy of Garruk Relentless. What's so special about this? The special thing is that Garruk Relentless is a double-faced card, while Clone isn't. Clone only copies the "Garruk Relentless" side of the card. And one of the copied abilities is "When Garruk Relentless has two or fewer loyalty counters on him, transform him."

So, what happens if Clone, which is a copy of Garruk, has less than three loyalty counters? It still may not seem like much: The ability tries to transform the clone, but since it can't (because it's not a double-faced card), it just does nothing.

Most people would just leave it at that. However, technically speaking, that's not the end of the story. What really happens is that when the clone's first ability triggers and resolves, it immediately triggers again. (A so-called state-trigger, which is what Garruk's first ability is, does not trigger again while its previous instantiation is still on the stack. However, once it resolves, it's free to trigger again.)

This, technically speaking, causes an unstoppable loop that doesn't allow the game to continue. Every time the ability triggers and resolves (and fails to transform the clone), it immediately triggers again, and so on, ad infinitum. The game cannot proceed because of this, unless something kills the clone (such as someone casting a Lightning Bolt on it.)

The proper result of this would be that the game ends in a draw.