Omnispell Adept — ruling 1

You may cast a sorcery this way even if it’s not your turn.

Omnispell Adept — ruling 2

If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, such as that of Severed Strands, those must be paid to cast the card.

Omnispell Adept — ruling 3

If a spell has {X} in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.

Omnispell Adept : règles, fonctionnement et interactions (MTG)

Omnispell Adept 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

, : You may cast an instant or sorcery spell from your hand without paying its mana cost.

How it works : Omnispell Adept

Original English text — Wizards of the Coast / Scryfall

#1October 5, 2018· Wizards of the Coast
You may cast a sorcery this way even if it’s not your turn.
No other card is named in this ruling.
#2October 5, 2018· Wizards of the Coast
If you cast a spell “without paying its mana cost,” you can’t choose to cast it for any alternative costs. You can, however, pay additional costs, such as kicker costs. If the card has any mandatory additional costs, such as that of Severed Strands, those must be paid to cast the card.
No other card is named in this ruling.
#3October 5, 2018· Wizards of the Coast
If a spell has in its mana cost, you must choose 0 as the value of X when casting it without paying its mana cost.
No other card is named in this ruling.