If any lawyer has ever told you that your "free speech" rights allow you to create a video game called Grand Theft Auto using the same font without being sued for trademark infringement, that lawyer should be disbarred.
Trademarks are designed to indicate source, and in this case, one of the most sucessul video games can register the name of their game as trademark for their game and related products. I've got no idea what you mean by "making a trademark out of a 'legal term'," but it seems to me you need to do some background reading before you attempt to create any IP.
Avvo doesn't pay us for these responses, and I'm not your lawyer just because I answer this question or respond to any follow-up comments. If you want to hire me, please contact me. Otherwise, please don't expect a further response. We need an actual written agreement to form an attorney-client relationship. I'm only licensed in CA and you shouldn't rely on this answer, since each state has different laws, each situation is fact specific, and it's impossible to evaluate a legal problem without a comprehensive consultation and review of all the facts and documents at issue.
You clearly cannot lawfully sell a video game entitled "Grand Theft Auto." Why? The explanation is far beyond the scope of this forum. You can understand why by reading the article linked to below. And note: active learning is a joy and an endeavor that builds character and wisdom -- do not rely on factoids haphazardly directed your way to learn about your world. Good luck.
The above is general information ONLY and is not legal advice, does not form an attorney-client relationship, and should NOT be relied upon to take or refrain from taking any action. I am not your attorney. You should seek the advice of competent counsel before taking any action related to your inquiry.
I hate that expression "some lawyers might tell". No competent lawyer "might tell you" free speech lets you use an immensely valuable trademark like GRAND THEFT AUTO for video games without a license from the trademark owner. It is absolutely fair for someone to make a trademark out of a common term if, through huge advertising and promotion and popularity, they can get the public to associate that term with them rather than what it formerly was. When you hear PREMIUM saltines do you think of all high priced saltines or do you think of Nabisco's famous brand of saltines? When you hear of APPLE computers do you think that the computer is shaped like an apple or made from apples or do you think of Steve Jobs and the best computer products in the world? It is the way it should be. You should not be free to use those terms for your products because the consuming public would be deceived and you would be free-riding on the investment and work and creativity of someone else.
I am not your lawyer and you are not my client. Free advice here is without recourse and any reliance thereupon is at your sole risk. This is done without compensation as a free public service. I am licensed in IL, MO, TX and I am a Reg. Pat. Atty. so advice in any other jurisdiction is strictly general advice and should be confirmed with an attorney licensed in that jurisdiction.
You appear to have some misconceptions regarding trademark law. Your main gripe appears to be that "grand theft auto" is commonly used to describe motor vehicle theft, and you would argue that "grand theft auto" is merely descriptive of a video game about stealing cars. Normally, one cannot obtain trademark rights for a descriptive term, but if that merely descriptive term comes to be known by the public as specifically designating that video game product, then it has developed secondary meaning that may support trademark rights. "Grand Theft Auto" is now a well-known video game (as you appear to recognize) and should be able to establish secondary meaning in the marketplace. If you were to sell a video game called Grand Theft Auto using the same font, consumers would likely be confused into thinking this was part of the existing series of Grand Theft Auto games, and you probably would be liable for trademark infringement. You are less likely to have a problem if you wanted to start a chain of restaurants called Grand Theft Auto because the goods and services are different which makes confusion less likely. This is not a question of "free speech" but one of fair competition.
This answer is for informational purposes only. It is not intended as specific legal advice regarding your question. The answer could be different if all of the facts were known. This answer does not establish an attorney-client relationship.
On what planet might this seem OK? No. Find another name.
The author is a Maryland attorney; however no answer given on Avvo is intended as legal advice or intended to create an attorney-client relationship. Dan's expertise lies in the electronic entertainment (video game) industry, as well as complex internet law issues, electronic free speech, entertainment law, copyright and trademark law, and computer fraud. He primarily represents game developers and founders of emergent internet technologies.