I just want to add that party is brilliant draft mechanic for "how to do tribal the right way" in this set.
Pretend green doesn't exist for a moment (because they get to play with lands this set). Each color gets a major tribe and a minor tribe, and the gold cards are payoffs for the tribal decks.
: Major: Clerics, minor Warriors. Tribal Common: Expedition Healer
: Major: Wizards, minor Rogues. Tribal Common: Expedition Diviner
: Major: Rogues, minor Clerics. Tribal Common: Expedition Skulker
: Major: Warriors, minor Wizards. Tribal Common: Expedition Champion
Match a major and minor color, and you've got a tribal deck:
So that sets the stage for tribal drafting, but how do you keep tension in the draft once players are in their lanes? The biggest problem with tribal is it can tend to be poisonous. Introducing the Party mechanic, which incentivizes players who are not drafting tribal decks to compete for tribal cards.
If you're in a non-green color, and miss the tribal boat, you can pick up bits and pieces of the other drafters' tribes, and play party. Of course, the two color pairs which don't have major/minor pairs that line up, pair perfectly for this concept:
: White: Clerics, Warriors. Blue: Wizards, Rogues. Party!
: Black: Rogues, Clerics. Red: Warriors, Wizards. Party!
And the sign-post uncommons help anchor these pairs. And a colorless payoff for on-color stragglers
I also quite like the second set of tribal uncommons, which obviously work best in the on-color tribal decks, but are playable anywhere with a critical mass. Any blue deck, for instance, can play Relic Amulet with confidence that spells and blue wizards will make it a strong card.
So there's some ability to mix-and-match tribal colors, and while not the focus of green, there are a few good green cards which are party types as well.
Then you have the "off-pair" cards. These cards are less than average but provide their color with unique card types (Farsight Adept, for example, is the only White Wizard at common).
What's very cool here, is the ability text on Farsight Adept is "Wizard". For a deck with party cards at all, this can be worth a half card or more. It can get you an extra scry, and extra drain, or even save you a mana each time you cast a spell with party.
Unfortunately, the Cleric and Vampire are misses here, they're still
too weak even with this advantage.
Finally, we get to the cog-iest cog card maybe ever.
Wizards has been trying to make (Bronze Sable
, Field Creeper
, etc) work in retail sets for a long time, and they've finally got it right. It hits the right power level as a two-drop with upside without being oppressive, and opens up a huge swath of options for deck construction. The tribal color pairs love this card as extra hits to their tribal synergy cards while being off-type to boost party. The off-tribal party decks love this card to hit party more consistently. And off-color and green decks love the ability to get creative and join in on the tribal strategies when they normally wouldn't be able to.
Party is a brilliant mechanic and enables a very unique draft structure and inventive color wheel, supporting cohesive tribal play while encouraging all drafters to fight for tribal cards.