word choice - Which is correct: "is it worth it?" or "does it worth it?"

Which one should I prefer?

Is it worth it?

or

Does it worth it?

Additionally, is the following form (without it) correct?

Is it worth?

Answer

Which one should I prefer?

Is it worth it?

or

Does it worth it?

"Is it worth it?" is correct.

Additionally, is the following form (without it) correct?

Is it worth?

No, that's wrong, worth always needs another word, like "worth twenty pounds" or something.