Brilliant Ultimatum — ruling 2

One of the piles may have zero cards in it if the opponent wishes.

Brilliant Ultimatum — ruling 3

You play cards from the chosen pile as part of the resolution of Brilliant Ultimatum. You may play them in any order. Timing restrictions based on the card’s type (such as creature or sorcery) are ignored. Other play restrictions are not (such as “Cast [this card] only during combat”). You play all of the cards you like, putting land onto the battlefield and spells on the stack, then Brilliant Ultimatum finishes resolving and is put into your graveyard. The spells you cast this way will then resolve as normal, one at a time, in the opposite order that they were put on the stack.

Brilliant Ultimatum — ruling 4

You can play a land card from the chosen pile only if it’s your turn (which it probably is, since Brilliant Ultimatum is a sorcery) and you haven’t yet played a land this turn. That means that if there are two lands in the chosen pile, you’ll be able to play a maximum of one of them.

Brilliant Ultimatum — ruling 5

If you cast a card “without paying its mana cost,” you can’t pay any alternative costs. You can pay additional costs, such as conspire costs and kicker costs.

Brilliant Ultimatum — ruling 6

The cards in the pile that wasn’t chosen remain exiled. Likewise, any cards in the chosen pile that you can’t play or you choose not to play remain exiled.

Brilliant Ultimatum : règles, fonctionnement et interactions (MTG)

Brilliant Ultimatum is one of those cards players keep asking about. Here is, in plain words, what its official text says, the rulings published by Wizards of the Coast, and the combos players actually run.

Official card text

Exile the top five cards of your library. An opponent separates those cards into two piles. You may play lands and cast spells from one of those piles. If you cast a spell this way, you cast it without paying its mana cost.

How it works : Brilliant Ultimatum

Original English text — Wizards of the Coast / Scryfall

#1October 1, 2008· Wizards of the Coast
The cards are exiled face up.
No other card is named in this ruling.
#2October 1, 2008· Wizards of the Coast
One of the piles may have zero cards in it if the opponent wishes.
No other card is named in this ruling.
#3October 1, 2008· Wizards of the Coast
You play cards from the chosen pile as part of the resolution of Brilliant Ultimatum. You may play them in any order. Timing restrictions based on the card’s type (such as creature or sorcery) are ignored. Other play restrictions are not (such as “Cast [this card] only during combat”). You play all of the cards you like, putting land onto the battlefield and spells on the stack, then Brilliant Ultimatum finishes resolving and is put into your graveyard. The spells you cast this way will then resolve as normal, one at a time, in the opposite order that they were put on the stack.
No other card is named in this ruling.
#4October 1, 2008· Wizards of the Coast
You can play a land card from the chosen pile only if it’s your turn (which it probably is, since Brilliant Ultimatum is a sorcery) and you haven’t yet played a land this turn. That means that if there are two lands in the chosen pile, you’ll be able to play a maximum of one of them.
No other card is named in this ruling.
#5October 1, 2008· Wizards of the Coast
If you cast a card “without paying its mana cost,” you can’t pay any alternative costs. You can pay additional costs, such as conspire costs and kicker costs.
No other card is named in this ruling.
#6October 1, 2008· Wizards of the Coast
The cards in the pile that wasn’t chosen remain exiled. Likewise, any cards in the chosen pile that you can’t play or you choose not to play remain exiled.
No other card is named in this ruling.