Some of you may have heard of this format before, but I hadn't until about a week ago. It is on the Wizards website of casual formats and it's name is Freeform. The rules are: 40+ cards. That's it. No ban list, UN sets legal, and you may have as many copies of a card as you want in your deck. It is traditionally played online, but can be proxied too. A meta has already developed, which I'll discuss in the next section.
Because of the low cost and card restrictions, Black Lotus and Spirit Guides have become the mana producers of choice (for obvious reasons). There are 3 primary archetypes that a Freeform deck needs to be or beat: Chancellor, Flames, and Leylines.
Chancellor
The typical Chancellor build is:
40x Chancellor of the Dross
This is the simplest deck in Freeform. All you do is draw seven cards, then win on the first upkeep by leeching 21 life out of your opponent. Despite being pretty unversatile and absolutely useless after the first turn, there are very few ways to beat this deck.
*Variation: Some decks have more than 40 cards in order to beat the mirror matchup by drawing them out. This is practically the only deck that can dramatically increase the number of cards, though, as it doesn't detract from consistency.
Flames
The typical Flames build is:
20x Simian Spirit Guide
20x Surging Flame
This deck works at instant speed by exiling 2 Spirit Guides from your hand, then casting Surging Flame, rippling through your entire deck, and winning. Flames will almost always beat Chancellor, as Chancellor's trigger happens at one set time, whereas Flames can respond.
*Variation: Some Flames decks add Leyline of Sanctity in order to beat the mirror matchup. Which brings us to the final major archetype...
Leylines
The typical Leylines build is:
29x Leyline of Sanctity
5x Serra's Sanctum
6x Opalescence
Leylines is a more controlling-type deck, as opposed to the other two that win almost instantly. Because of the very high number of Leylines of Sanctities, Flames won't be able to target it and the deck will go on to beat its opponent down with 4/4s. However, since Chancellor's ability doesn't target, Leylines will always lose to Chancellor.
*Variation: Starfield of Nyx is sometimes mixed in with Opalescence on the off chance that opponents find a way to destroy Opalescence then Surgical Extraction it.
These decks form a sort of rock-paper-scissors game in the format, which would make it purely a game of chance. But with every deck that is created that can consistently beat any two of these "Power Three", a new dimension is added to the format which makes games more complex and fun.
That is what I've aimed to do with the above deck: it will beat any of the Three about 75% of the time. The hoped-for result is a beatdown with Sphinx of the Chimes and Zephid. Here's how it beats any of the three decks:
Against Chancellor, what this deck needs is an Elvish Spirit Guide and a Healing Leaves in its opening hand. In response to the Chancellor trigger, it simply gains 3 life. The Chancellor deck cannot do more than 21 damage a game, so they will probably scoop (although they wouldn't have any cards to do so) after their strategy fails.
Against Flames, this deck wins in much the same way Leylines does: Leyline of Sanctity. Once its out there, the Flames deck can only win by drawing you out. But that's where Zephid comes in. You need an untargetable creature to beat down with, or Flames will burn it down.
Against Leylines, the key card is Back to Nature. It is a 4-of because Leylines can't win immediately and there's a chance it won't have Opalescence in its opening hand anyway. The god hand-refiller Sphinx of the Chimes helps out here. In your opening hand, there's about a 90% chance you will have 2 of any card. Once you draw 4 more, there's an even better chance. So, with Turn-1 potential, finding an early Back to Nature isn't hard.
The ultimate dream hand would be 2x Black Lotus, 1x Leyline, 1x Healing Leaves, 1x Back to Nature, 1x Elvish Spirit Guide, and 1x Sphinx.
I hope you liked this introduction to a quirky, fun format. I challenge you to also create a deck that would decently compete against these Three . Good deckbuilding to you all.