How widely is “catch-22” used?

Solution 1:

It's the title of a classic Joseph Heller novel about World War II, published in 1961 and adapted for film in 1970. Heller invented the term to describe absurd, impossible-to-escape situations; he actually uses it rather loosely, so that it can cover almost anything. The main statement of the concept:

There was only one catch and that was Catch-22, which specified that a concern for one's own safety in the face of dangers that were real and immediate was the process of a rational mind. Orr was crazy and could be grounded. All he had to do was ask; and as soon as he did, he would no longer be crazy and would have to fly more missions. Orr would be crazy to fly more missions and sane if he didn't, but if he was sane, he had to fly them. If he flew them, he was crazy and didn't have to; but if he didn't want to, he was sane and had to. Yossarian was moved very deeply by the absolute simplicity of this clause of Catch-22 and let out a respectful whistle.

"That's some catch, that Catch-22," he observed.

"It's the best there is," Doc Daneeka agreed.

Some other examples:

Catch-22 states that agents enforcing Catch-22 need not prove that Catch-22 actually contains whatever provision the accused violator is accused of violating.

and

Catch-22 says they have a right to do anything we can’t stop them from doing.

Catch-22 is an enhanced version of the classic "Damned if you do, and damned if you don't."

Now, how widely known is the phrase? In the United States, very nearly universal - even among people who've never read or heard of the book and movie. In the rest of the English-speaking world? I have no idea...

http://en.wikipedia.org/wiki/Catch-22_(disambiguation)

Even if people don't fully understand "catch-22" they probably get that it means basically "to be stuck between a rock and a hard place".

Solution 2:

Google NGrams shows "catch-22" flatlining, but "catch 22" has had some interesting play:

Nevertheless, a Google search for "catch-22" (which will be case insensitive and treating the hyphen as optional), shows 5,300,000 hits.

In my own experience it's a fairly common usage and well understood.

EDIT:

Actually, with the hyphen is preferred; Google Ngrams just needs the hyphen to be delimited by spaces: