It wouldn't be straight up domain-esque, but I'm also too distracted by PT JOU to really think of something.

The win-con I can do easily.

"At the beginning of your upkeep, you may reveal your hand. If you do, and you have an artifact card, a creature card, an enchantment card, and instant card, a land card, a sorcery card, and a planeswalker card in your hand, you win the game."

Planeswalker is under consideration for removing, but the completeness is just too tempting to leave incomplete.

The permanent card types are artifact, creature, enchantment, land, and planeswalker thus the only way I can see a domain abilty is by overcosting cards (because you'll always have at least 1 card type on the battlefield, and it'll be to easy to get at the very least 2 and more likely 3). or by saying "If you control four or more card types among permanents you control, [effect]."

I'm still working on it between matches lol.

The problem with card types on the battlefield is that it will nearly always be 2. Most decks play many creatures and lands, no artifacts, enchantments, or planeswalkers, and some instants or sorceries that don't count.

But in this set it will almost always be three, probably four.
The point of the ability is to be built around.

What about TYPE Abilityname - Do cool stuff when you play type?

Creaturefall!
That could work, but I feel it should be limited to creatures if only because they have storm for instants / sorceries (i mean spells in general, but lets be honest here) or even Izzet, landfall for lands, affinty for artifacts, constellation for enchantments. The last real missing piece is planeswalkers and creatures. Creatures are the only ones that can go common.

...
What are you talking about?

How this is similar to landfall but for other types.
And how that because they have a specific ability lands artifacts enchantments, and practically one for instants / sorceries, why not do one for creatures?

I'm not necessarily on board with that idea but it should trigger on ETB rather than on cast so that it works with relics.

This.

Alright guys. I'm about to blow your minds.

Disclaimer: This isn't an entirely original idea. turnip_song came up with the design space years ago on the old forums, but it didn't really work within the rules. I think my way works, though.

New card type: Subzone.

Subzones aren't permanents. They can't be targeted or destroyed. Think of them like emblems. You do, however, cast them from your hand.

Artistically, I imagine them like regular-sized plane cards – horizontal, with the art filling up the whole card.

Each subzone has one of six subtypes: Library, Hand, Stack, Battlefield, Graveyard, or Exile. Usually Battlefield, although theoretically any of them could work. Library would be the trickiest.

Whenever a permanent would enter the zone of the subzone's subtype, you may have it enter the subzone instead. A card can be in any number of subzones of the same subtype at a time. They don't function like legendary cards or world enchantments.

I don't know how to explain it any further besides posting examples:

Forgotten Factory –
Subzone – Battlefield
(Whenever a permanent would enter the battlefield, you may have it enter Forgotten Factory instead.)
Permanents in Forgotten Factory are artifacts in addition to their other types.

Pastures of Enlightenment –
Subzone – Battlefield
(Whenever a permanent would enter the battlefield, you may have it enter Pastures of Enlightenment instead.)
Permanents in Pastures of Enlightenment are enchantments in addition to their other types.

Realm of Vapor –
Subzone – Battlefield
(Whenever a permanent would enter the battlefield, you may have it enter Realm of Vapor instead.)
Creatures in Realm of Vapor can only block or be blocked by other creatures in Realm of Vapor.

Eerie Cemetary –
Subzone – Graveyard
(Whenever a card would be put into your graveyard, you may put it into Eerie Cemetary instead.)
At the beginning of your upkeep, you may return a creature card in Eerie Cemetary to its owner's hand.

Pyromancer's Tower –
Subzone – Hand
(Whenever a card would be put into your hand, you may put it into Pyromancer's Tower instead.)
Whenever a spell cast from Pyromancer's Tower would deal damage, it deals that much damage plus 1 instead.

Lion's Den –
Subzone – Hand
(Whenever a card would be put into your hand, you may put it into Lion's Den instead.)
Creature spells cast from Lion's Den cost less to cast.

Zone Control –
Enchantment
At the beginning of your upkeep, if you control a Battlefield subzone, a Graveyard subzone, and a Hand subzone, you win the game.

Does all that make sense? What do you guys think? My heart is literally beating very fast right now; that's how excited I am about this idea.

That has been done before but I could see it working here. But I cab see a lot of people not liking it.

I'm interested in the idea, but it might be a bit confusing especially having them be in any number of the same subzone type. I would think it could only be one.
I've toyed with the idea of "buildings" before where you can attach creatures to it.

I feel like there would be a bit too much complication.
If I have a creature in a subzone - battlefield, can it attack or block? If so, is it limited to other things in that subzone, or does it then leave the subzone?
I'm not overly enthused by subzone library, if only that it's very awkward.
Not being able to be targeted is a bad thing. I'd say let it be targeted, but (obviously) don't design something that can destroy it... or do (Worldfire, Beast Within etc.)
Is there a limit to how many things can be in a subzone?

That's all I can think of for now... I think it's an interesting idea, but it will need fine tuning before we should use it.

Regarding the Set Map: I did some math. All the Wizards sets since they shrinked the average big set size except for Innistrad (which was special because of the double-faced cards) has had 101 Commons, 60 Uncommons, 53 Rares, and 15 Mythics. It was important to me that the ratios between the rarities were the same, but that the set be just a little bit bigger than that. So that leaves us with 108 Commons, 64 Uncommons, 57 Rares, and 16 Mythics. Before it was 108 Commons, 72 Uncommons, 60 Rares, and 16 Mythics, which I did because I like multiples of 12. But I figured it was more important that the ratios stay the same. So I had to cut 8 Uncommons and 3 Rares, or 11 cards total, leaving us with 245 cards to design instead of 256.

There are now 18 Commons, 10 Uncommons, 8 Rares, and 3 Mythics in each color.
There are now 13 Commons, 9 Uncommons, 5 Rares, and 1 Mythic in Artifacts.
There are now 10 Rares in Multicolor. (A 10-card cycle, one for each two- or three-color combination.)
There are now 5 Commons, 5 Uncommons, and 2 Rares in Lands. (A cycle each of Commons and Uncommons, plus 2 Rares for any cool Land ideas we might have.)

Does that work for everyone?

One thing that was brought up with one of the sets we were designing on the old forums was High Noon. It was an ability word similar in effect to the transform mechanic.

At a certain time, cards had a certain ability.
Things like, "As long as it's high noon,"
"When it becomes high noon,"

Sometimes it was a good thing, sometimes it was a negative thing.
If we could implement this we could do one for hot and one for cold High Noon, versus Deep Freeze.

Those could be our "factions".

It feels like all of these could be done in a way that didn't tear a gaping hole in the rules system.

Yeah, but then we wouldn't have a new card type.

I just think it would be really awesome to have a new card type, and everything else has been done before.

One suggestion I have...
Do one cycle of either Common or Uncommon.
Do one cycle of Rare.
Have a few in the other rarity.

Mostly because I like designing rare lands the best, especially if we think we are going to do triple colors this could be important.
I think having a cycle of commons and a cycle of rares would be best, with a few limited oriented uncommons? That really depends though on the triple color push.

I we want triple colors, then I think rare land cycle is needed. Otherwise what you have suggested is fine.

@Parad: We could always implement conspiracy cards

OK, I can swing that.

+1 Uncommon in each color (+5 Uncommons)
-1 Rare in each color (-5 Rares)

-2 Artifact Uncommons
+2 Artifact Rares

-3 Land Uncommons
+3 Land Rares

That leaves us with:

18 Commons, 11 Uncommons, 7 Rares, and 3 Mythics in each color;
13 Commons, 7 Uncommons, 7 Rares, and 1 Mythic in Artifacts;
10 Multicolor Rares;
and 5 Commons, 2 Uncommons, and 5 Rares in Lands.

Does that sound good?

I like those numbers.
The artifacts might need to be tweaked, it depends on how the set turns out. I think double digits is particularly high for a common slot, but that will be largely dependant on the set. It seems that it could be fine for now.
But, for a comparison...
Scars of Mirrodin had 88 total artifacts (35 common)
Theors had 18 total artifacts (5 common)