Como dizer "trunfo" em inglês

I have an Ace in the hole.

Talvez em referência ao naipe completo, diriamos "I have trump." "Trump suit" seria o naipe escolhido (ou predeterminado pelas regras) como trunfo. "Trump card" seria a carta que ganha a jogada.

"Trump" é um substantivo e verbo. O verbo "to trump" é usado frequentemente:

This trumps all other considerations. = Isso vale mais do que todas as outras considerações.
He won the bridge hand by trumping skillfully.

Regards

Olá Pessoal,

Complemento:

I have a trump card.

..."Second, even if defeated electorally, the Islamists and their regimes have a trump card: guns. Guns trump cellphones. Bang-bang beats tweet-tweet. The Sunni Awakening in Iraq succeeded because the moderates there were armed. I doubt Ahmadinejad will go peacefully."

http://www.nytimes.com/2009/06/17/opini ... edman.html
http://www.ldoceonline.com/dictionary/trump_1

Boa sorte!

Olá!!

Só pra adicionar mais uma sugestão às dadas pelo pessoal.

have something up one's sleeve and have an ace up one's sleeve
Fig. to have a secret or surprise plan or solution (to a problem). (Alludes to cheating at cards by having a card hidden in one's sleeve.) I've got something up my sleeve, and it should solve all your problems. I'll tell you what it is after I'm elected. The manager has an ace up her sleeve. She'll surprise us with it later.

Fonte: http://idioms.thefreedictionary.com/sleeve