BT Knights 12.15.16 (Modern)

Any creature type in Magic outside of a select few are eligible to be used (more on that later). Once you've chosen your "Tribe", you build a (minimum) 60 card deck (no sideboards are used) that has at least 25 creatures from the chosen Tribe. Everything else in the deck has to follow the current Modern format rules (including Banned List), but your tribe's creatures can go back to Alpha, if you want to, as any sets are allowed! (keep in mind that OTHER creatures in your deck that aren't related to your tribe have to be Modern legal).

Now, for the Banned Tribes List!:

(some are color-specific, for example, you can't use BLUE Wizards, but any other color Wizards are fine): Beasts, White Clerics, Green Elves, Blue Faeries, Zombies, Red Goblins, Merfolk, Slivers, White Soldiers, Blue Wizards, and Black Vampires. No creatures from these tribes can be used in this tournament. Note that Shapeshifters that have the "Changeling" keyword ability are exempted from this rule and may be used to represent any tribe. (Wanna build Elementals? This rule will help.) Oh yeah, and Elementals are still unbanned, so you can use them in this event.

Nowadays, we also have a specific Banned List for Bad Tribal!
The following cards are banned:

-Riders of Gavony