Most definately no. The exact same principles apply. The maps and textures are owned by iD, so you're not allowed to just use them.

The map format and editors for it you can use freely, I'm doing so as well.

Quote:Original post by rick_appleton
[...]The map format and editors for it you can use freely, I'm doing so as well.

While you can certainly use whatever format you want (barring patents on required algorithms), I'm fairly certain that id has restricted use of it's editing tools to its own games only.
Third party editors might be fine, but you'll need to read the EULAs for any tools you use.

Although I didn't expect it to be a problem, I did a quick search and found this page

http://www.qeradiant.com/?data=legal

saying the use of the editor is free for non-commercial use.

The use of the term "commercial" in this contest is kind of interesting. Us as competitors would want to consider these projects as non-commercial projects, but a copyright holder might just as easily say that it is commercial. Here's why:

#1 - The site that is running the contest is a for-profit corporation. The people that are sponsoring it are for-profit corporations as well.
#2 - While you may not be selling it, there is still a potential exchange for value: A prize which could be product and/or money.

Now its unlikely that someone will send off a cease and desist letter for a contest entry which won't yeild significant profit (in some cases *cough*), but those are just some things to consider.