Typical article size when going from Word to PDF/Print is 4-5 pages in word to 3-4 pages in print. This is due to a lowered PT size and tricks with layout software that allow us to cram more into a smaller space.

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You can get away with 8pt print (6pt reduced is hardly used but can be done as well) with kerning, mortising, and proper letting. This allows for more information to be presented in a readable format.
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Typical technical articles run anywhere from 3-6 pages in print. Some magazines (Servo, CircuitCellar, EE Times, etc) allow for more on feature articles and use smaller articles as "fillers" on pages with a lot of ad space.

The best bet is to write your article long (really long in some cases) and then put it down, walk away, and let it sit. Go back, re-read it and remove all the irrelevant crap that manged to find its way in. Of course, having a copy editor makes this easier as they do the minimizing for you

Also, writing it long will give you the advantage of exploring future topics. If you can break a large subject (game engines) into smaller subjects (graphics, scripting, playability, input, etc) then you have just created value for the future. So starting big works in both favors. Maybe you can cover a complex topic at a high level promising more detail in a later article. Julian Bucknall used to use this approach quite a bit with Algorithms Alfresco.

I talked to WILL about this earlier, and am looking to find the non docx format template we use for our magazines. If I can find it I'll post it up for ppl to utilize as they see fit. Of course I'll have to remove most of what directly pertains to our company, but most of that doesn't matter anyways

PS: Short version of my response:
4-5 pages at 10pt in word translates to about 3-4 pages in print.