united-states trademark
Is a name of a fictional character, location or universe free to use if it is not trademarked?
<p>After searching on USPTO names of characters fron Dota 2 and Warcraft, I found that most names are  not trademarked. Does this means these names are free to use as a software name?</p>

<p>Under US law, trademarks are only protected if they are &quot;used in commerce&quot;. In general this means the mark is used to describe or label a product or service, or to advertise it.</p>
<p>Note that words and images used in this way may get a degree of trademark protection even if they are not registered. Proof of use in commerce is sufficient to grant this protection.</p>
<p>However, the names of characters are not usually used as identifications of a product or service, nor as designations of source. If they are not so used, they do not have trademark protection.</p>
<p>If a reasonable person would be led by the use of a character name to incorrectly believe that the product had been authorized, sponsored, or endorsed by the creator of the character or a related entity, then that use might constitute an infringement. But usually this would not be the case.</p>
<p>For example, a software company calling itself &quot;SauronWare&quot; and distributing a word processor called &quot;SauronWriter&quot; would probably not infringe on the intelelctual property of the Tolkien Estate.</p>
<p>But trademark  law can be complex, and a would-be user wouldf be wise to consult a trademark lawyer.</p>
<p>Note also that song, book, and story titles, character names, and other short phrases are not subject to copyright protection under US law (see Copyright Office Circular 33.)</p>
