Foreign cards

[clavio]

I use Italian tabernacles, because they are cheaper. I played one against a goblin deck. He went, didn't pay any upkeeps, and drew his card. I told him all of his creatures needed to be sacrificed. He said that it was unfair, because he didn't know Italian.

He didn't ask what the card did when I played it.

Who is correct?

[Nightmare]

I use Italian tabernacles, because they are cheaper. I played one against a goblin deck. He went, didn't pay any upkeeps, and drew his card. I told him all of his creatures needed to be sacrificed. He said that it was unfair, because he didn't know Italian.

He didn't ask what the card did when I played it.

Who is correct?
Neither of you.

While it is legal to play foreign cards, and it is your opponent's responsibility to know what cards do and keep track of the gamestate, it is also yours. It's also against the rules to use foreign cards to garner an advantage. That being said, your opponent's creatures would be sacrificed, as it is an optional payment, and he has drawn a card, signifying both of you passing priority on an empty stack in the upkeep.