What’s the difference between a “little used car” and a “little-used car”? Between “more critical attacks” and “more-critical attacks”? Or, for that matter, between “toxic tort litigation” and “toxic-tort litigation”?
That’s why grammarians invented rules for multiword phrases known as “compound modifiers” or “phrasal adjectives.” In general, if two or more words modify another word and precede that word, hyphenate them.
If you think this country has too many lawsuits, you may very well complain to your buddies about the “toxic tort litigation” that’s ruining the economy. But if you’re on the plaintiff’s side, you likely believe that “toxic-tort litigation” helps make us safer. No need to obsess here: if your meaning is obvious, don’t feel obliged to hyphenate. So “criminal law attorney” and “affirmative action plan” are fine as is.
Now you can understand why the boldfaced phrases are hyphenated in the following two sentences from a recent New Yorker article about defense spending:
And if you want legal models, consider these examples from a brief written by the Chief Justice, who is also known to be one of the profession’s Chief Grammarians:
John Roberts, Alaska v. EPA
One more thing: If the first word in a multiword phrase ends in -ly, no hyphenation is required:
John Roberts, Alaska v. EPA