play dirty

"I don't play dirty tricks myself," replied Antonia, with dignity.

But be careful, because if Jupiter Equilateral is involved in it, they're going to play dirty.

Now what is this but making use of religion to play dirty politics?

"My dear General, when you play dirty tricks it is necessary that they be successful!"

Oh, they dont play dirty, if you mean that; but they dont let any chances slip, believe me!