Planescape: Comments

>"Prismatic - (This card is all colors at all times.)

Resonant - (This spell's colors are the colors of mana spent to cast it.)"

These two mechanics seem redundant.

They are similar. Resonant is the one that you can do more interesting things with, and in a choice between the two I'd keep Resonant. Prismatic seems like something I'd likely use relatively rarely as a non-keyworded ability on a handful of cards, like the effect on Transguild Courier (which almost begs to be a reprint here).

So far I'm getting the feeling as well that Prismatic would be hard to use as a mechanic in all colors and at common, without flavor fails.

I'm still getting a feel for what the mechanics are going to be here. Aside from nonbasic landcycling I'm scratching my head about what to do with "land matters" without giving in to the temptatation to simply port Discovery over to this. It'd be too simple to do that.

Explore seems like an intuitive possibility to use as a returning land-matters mechanic.

Another possibility I'm kicking around is if Devoid would actually fit into this set, particularly representing the Modrons and the more neutral artifact side of the equation, but that also clashes with the multicolor-matters thing, unless I could work it within the set into a dominant tension between the two (Multicolor vs. Colorless).

Minor Update:

I have scrapped the Prismatic keyword, but moved it over to a non-keyworded mechanic to be used sparingly, mainly via a reprint of Transguild Courier.

I placed the Nathri race in a more fitting color (), while putting the Tuladhara in an additional color ().

I may re-map the races to the colors a little bit, without all of them being necessarily represented by just one color. As long as the flavor is right, I suppose the chips can fall where they may about that a little. What matters is that the races feel like their color(s).

I'm also considering adding a mechanic like this:

Vibrant - Whenever you cast a spell that shares a color with this, [effect].

This creates combos with Resonant while further representing the color matters theme. On the face of it, it may appear to be more of a "mono-color matters" type of mechanic, but in the same set as Resonant and otherwise with lots of multicolor stuff, it does not function that way.

A more straight forward variant might simply be "Whenever you cast a multicolor spell", but I'm not sure about that approach here.

Or perhaps something more specific, like "Whenever you cast a [Color] spell", as an off-color thing. That would more explicitly encourage specific multicolor combinations.

Update:

I have scrapped the entire premise of using color/multicolor as a set theme, and instead opted for "exile matters" and DFC as a set themes, and altered the list of set themes and mechanics accordingly.

I have added the Portal Mechanic for instants and sorceries, which potentially enables a lot of designs.

Portal - [Cost] (Exile this spell as it resolves. You may cast it transformed from exile for its portal cost.)

I also have assigned some provisional archetypes to the factions which seem fairly fitting. For example, Dustmen have Graveyard and Exile matters archetypes, while The Mind's Eye have Library and Hand matters archetypes.

I'm considering scrapping Explore and replacing it with some other sort of creature ability.

Update:

I've added a color scheme for the outer planes, though it required skipping one of them (there are 16, and I am using 15 of them). There are 5 planes associated with a single color, and 10 planes associated with dual color pairs. I tried to match the flavor as much as possible and it seems mostly to fit decent, with some possible finagling.

There is no way to perfectly map MTG's colors to DnD's alignment system, but the colors are usable and somewhat bendable to represent the more specific flavor of particular planes.