The Chainmail miniatures wargame, grandaddy to D&D, is once again available in PDF format at One Book Shelf for $4.99. Apparently this is the 7th printing of the 3rd Edition, so many (or all?) of the Tolkien references have been omitted or changed. But still worth the price if you’d like to look at a piece of gaming history. Cheers!
Edit: I can confirm that hobbits have been changed to halflings, and balrogs have been removed entirely. There may be other changes as well, but those are the two big ones I noticed right away.